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  • Unable to PPTP through NAT on Cisco 881

    - by MasterRoot24
    I'm trying to connect to a PPTP server which is sat behind a Cisco 881 NAT router. The server is running Ubuntu Server 12.04 and is running Poptop pptpd as the PPTP daemon listening for connections. As discussed in my other question, I'm trying to setup a Cisco 881 router to replace my old Linksys WAG320N. This same server and WAN connection worked fine with the WAG320N with no special configuration, other than allowing 1723 in through the firewall. On the Cisco 881, I'm using the newer ip nat enable or NAT NVI to setup static routes in through the firewall for the services running behind the router. My reason being that I can't run another copy of my live DNS domains internally with local IP addresses in. For the purposes of this question, though, I have rebuilt the router with ip nat inside/outside style NAT'ing, but this issue is still apparent. HTTP/SMTP/IMAP etc. all work ok from both the WAN and LAN interfaces of the router. I'm only having issues with SIP (see other question) and PPTP. My issue is that the GRE doesn't appear to be passing through NAT correctly and one end of the connection is not receiving GRE traffic when it should be, so the server hangs up the connection. Here's an example of /var/log/syslog with debug enabled in /etc/pptpd.conf: Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: MGR: Launching /usr/sbin/pptpctrl to handle client Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: local address = 192.168.1.50 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: remote address = 192.168.1.51 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: pppd options file = /etc/ppp/pptpd-options Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Client 82.132.248.216 control connection started Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 1) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Made a START CTRL CONN RPLY packet Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: I wrote 156 bytes to the client. Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Sent packet to client Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 7) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Set parameters to 100000000 maxbps, 64 window size Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Made a OUT CALL RPLY packet Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Starting call (launching pppd, opening GRE) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: pty_fd = 6 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: tty_fd = 7 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: I wrote 32 bytes to the client. Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Sent packet to client Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): program binary = /usr/sbin/pppd Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): local address = 192.168.1.50 Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): remote address = 192.168.1.51 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded. Dec 11 21:06:30 <HOSTNAME> pppd[22627]: pppd 2.4.5 started by root, uid 0 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Using interface ppp0 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Connect: ppp0 <--> /dev/pts/3 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: GRE: Bad checksum from pppd. Dec 11 21:06:31 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 15) Dec 11 21:06:31 <HOSTNAME> pptpd[22626]: CTRL: Got a SET LINK INFO packet with standard ACCMs Dec 11 21:07:00 <HOSTNAME> pppd[22627]: LCP: timeout sending Config-Requests Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Connection terminated. Dec 11 21:07:00 <HOSTNAME> avahi-daemon[1042]: Withdrawing workstation service for ppp0. Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Modem hangup Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Exit. Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: GRE: read(fd=6,buffer=6075a0,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7) Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Reaping child PPP[22627] Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Client 82.132.248.216 control connection finished Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Exiting now Dec 11 21:07:00 <HOSTNAME> pptpd[5803]: MGR: Reaped child 22626 As far as Cisco are concerned, all I need is ip nat source static tcp <SERVER LAN IP> 1723 interface FastEthernet4 1723 but of course this doesn't seem to the be helping the GRE traffic through as it should. Trying the connection to the LAN IP of the server from the same LAN as the server (behind the router), the PPTP connection works fine, so I'm confident that the server's config is ok. Furthermore, all I needed on my WAG320N was to open 1723 in the firewall. Here's my current router config: ! ! Last configuration change at 20:20:15 UTC Tue Dec 11 2012 by xxx version 15.2 no service pad service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! hostname xxx ! boot-start-marker boot-end-marker ! ! enable secret 4 xxxx ! aaa new-model ! ! aaa authentication login local_auth local ! ! ! ! ! aaa session-id common ! memory-size iomem 10 ! crypto pki trustpoint TP-self-signed-xxx enrollment selfsigned subject-name cn=IOS-Self-Signed-Certificate-xxx revocation-check none rsakeypair TP-self-signed-xxx ! ! crypto pki certificate chain TP-self-signed-xxx certificate self-signed 01 xxx quit ip gratuitous-arps ip auth-proxy max-login-attempts 5 ip admission max-login-attempts 5 ! ! ! ! ! ip domain list dmz.xxx.local ip domain list xxx.local ip domain name dmz.xxx.local ip name-server 192.168.1.x ip cef login block-for 3 attempts 3 within 3 no ipv6 cef ! ! multilink bundle-name authenticated license udi pid CISCO881-SEC-K9 sn xxx ! ! username admin privilege 15 secret 4 xxx username joe secret 4 xxx ! ! ! ! ! ip ssh time-out 60 ! ! ! ! ! ! ! ! ! interface FastEthernet0 no ip address ! interface FastEthernet1 no ip address ! interface FastEthernet2 no ip address ! interface FastEthernet3 switchport access vlan 2 no ip address ! interface FastEthernet4 ip address dhcp ip nat enable duplex auto speed auto ! interface Vlan1 ip address 192.168.1.x 255.255.255.0 no ip redirects no ip unreachables no ip proxy-arp ip nat enable ! interface Vlan2 ip address 192.168.0.x 255.255.255.0 ! ip forward-protocol nd ip http server ip http access-class 1 ip http authentication local ip http secure-server ! ! ip nat source list 1 interface FastEthernet4 overload ip nat source list 2 interface FastEthernet4 overload ip nat source static tcp 192.168.1.x 1723 interface FastEthernet4 1723 ! ! access-list 1 permit 192.168.0.0 0.0.0.255 access-list 2 permit 192.168.1.0 0.0.0.255 ! ! ! ! control-plane ! ! banner motd Authorized Access only ! line con 0 exec-timeout 15 0 login authentication local_auth line aux 0 exec-timeout 15 0 login authentication local_auth line vty 0 4 access-class 2 in login authentication local_auth length 0 transport input all ! ! end UPDATE 16/12/2012: The only progress that I have been able to make on this issue is that I'm confident that the issue is caused by the GRE tunnels (which are required for the PPTP connection to complete) are being blocked. When attempting a connection, I can see in show ip nat nvi translations that both a TCP translation on 1723 is setup and also a GRE translation is setup also. I appear to be able to see GRE related packets on the LAN that the server is on, so I am lead to believe that the server is sending(?) GRE packets, however running Wireshark on a client PC when attempting a connection shows absolutely no GRE packets. Whilst there are no configuration directives in my config posted above (that I can pin point) which would specifically block them, it would appear that the GRE packets are not being allowed in/out of the router's firewall, even though a NAT translation entry is setup to the server's LAN address. Would anyone be able to provide me with some help to ensure that GRE packets are not blocked by the router's firewall, so that this can be ruled out as a possible issue please?

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  • Unusually high dentry cache usage

    - by Wolfgang Stengel
    Problem A CentOS machine with kernel 2.6.32 and 128 GB physical RAM ran into trouble a few days ago. The responsible system administrator tells me that the PHP-FPM application was not responding to requests in a timely manner anymore due to swapping, and having seen in free that almost no memory was left, he chose to reboot the machine. I know that free memory can be a confusing concept on Linux and a reboot perhaps was the wrong thing to do. However, the mentioned administrator blames the PHP application (which I am responsible for) and refuses to investigate further. What I could find out on my own is this: Before the restart, the free memory (incl. buffers and cache) was only a couple of hundred MB. Before the restart, /proc/meminfo reported a Slab memory usage of around 90 GB (yes, GB). After the restart, the free memory was 119 GB, going down to around 100 GB within an hour, as the PHP-FPM workers (about 600 of them) were coming back to life, each of them showing between 30 and 40 MB in the RES column in top (which has been this way for months and is perfectly reasonable given the nature of the PHP application). There is nothing else in the process list that consumes an unusual or noteworthy amount of RAM. After the restart, Slab memory was around 300 MB If have been monitoring the system ever since, and most notably the Slab memory is increasing in a straight line with a rate of about 5 GB per day. Free memory as reported by free and /proc/meminfo decreases at the same rate. Slab is currently at 46 GB. According to slabtop most of it is used for dentry entries: Free memory: free -m total used free shared buffers cached Mem: 129048 76435 52612 0 144 7675 -/+ buffers/cache: 68615 60432 Swap: 8191 0 8191 Meminfo: cat /proc/meminfo MemTotal: 132145324 kB MemFree: 53620068 kB Buffers: 147760 kB Cached: 8239072 kB SwapCached: 0 kB Active: 20300940 kB Inactive: 6512716 kB Active(anon): 18408460 kB Inactive(anon): 24736 kB Active(file): 1892480 kB Inactive(file): 6487980 kB Unevictable: 8608 kB Mlocked: 8608 kB SwapTotal: 8388600 kB SwapFree: 8388600 kB Dirty: 11416 kB Writeback: 0 kB AnonPages: 18436224 kB Mapped: 94536 kB Shmem: 6364 kB Slab: 46240380 kB SReclaimable: 44561644 kB SUnreclaim: 1678736 kB KernelStack: 9336 kB PageTables: 457516 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 72364108 kB Committed_AS: 22305444 kB VmallocTotal: 34359738367 kB VmallocUsed: 480164 kB VmallocChunk: 34290830848 kB HardwareCorrupted: 0 kB AnonHugePages: 12216320 kB HugePages_Total: 2048 HugePages_Free: 2048 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 5604 kB DirectMap2M: 2078720 kB DirectMap1G: 132120576 kB Slabtop: slabtop --once Active / Total Objects (% used) : 225920064 / 226193412 (99.9%) Active / Total Slabs (% used) : 11556364 / 11556415 (100.0%) Active / Total Caches (% used) : 110 / 194 (56.7%) Active / Total Size (% used) : 43278793.73K / 43315465.42K (99.9%) Minimum / Average / Maximum Object : 0.02K / 0.19K / 4096.00K OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME 221416340 221416039 3% 0.19K 11070817 20 44283268K dentry 1123443 1122739 99% 0.41K 124827 9 499308K fuse_request 1122320 1122180 99% 0.75K 224464 5 897856K fuse_inode 761539 754272 99% 0.20K 40081 19 160324K vm_area_struct 437858 223259 50% 0.10K 11834 37 47336K buffer_head 353353 347519 98% 0.05K 4589 77 18356K anon_vma_chain 325090 324190 99% 0.06K 5510 59 22040K size-64 146272 145422 99% 0.03K 1306 112 5224K size-32 137625 137614 99% 1.02K 45875 3 183500K nfs_inode_cache 128800 118407 91% 0.04K 1400 92 5600K anon_vma 59101 46853 79% 0.55K 8443 7 33772K radix_tree_node 52620 52009 98% 0.12K 1754 30 7016K size-128 19359 19253 99% 0.14K 717 27 2868K sysfs_dir_cache 10240 7746 75% 0.19K 512 20 2048K filp VFS cache pressure: cat /proc/sys/vm/vfs_cache_pressure 125 Swappiness: cat /proc/sys/vm/swappiness 0 I know that unused memory is wasted memory, so this should not necessarily be a bad thing (especially given that 44 GB are shown as SReclaimable). However, apparently the machine experienced problems nonetheless, and I'm afraid the same will happen again in a few days when Slab surpasses 90 GB. Questions I have these questions: Am I correct in thinking that the Slab memory is always physical RAM, and the number is already subtracted from the MemFree value? Is such a high number of dentry entries normal? The PHP application has access to around 1.5 M files, however most of them are archives and not being accessed at all for regular web traffic. What could be an explanation for the fact that the number of cached inodes is much lower than the number of cached dentries, should they not be related somehow? If the system runs into memory trouble, should the kernel not free some of the dentries automatically? What could be a reason that this does not happen? Is there any way to "look into" the dentry cache to see what all this memory is (i.e. what are the paths that are being cached)? Perhaps this points to some kind of memory leak, symlink loop, or indeed to something the PHP application is doing wrong. The PHP application code as well as all asset files are mounted via GlusterFS network file system, could that have something to do with it? Please keep in mind that I can not investigate as root, only as a regular user, and that the administrator refuses to help. He won't even run the typical echo 2 > /proc/sys/vm/drop_caches test to see if the Slab memory is indeed reclaimable. Any insights into what could be going on and how I can investigate any further would be greatly appreciated. Updates Some further diagnostic information: Mounts: cat /proc/self/mounts rootfs / rootfs rw 0 0 proc /proc proc rw,relatime 0 0 sysfs /sys sysfs rw,relatime 0 0 devtmpfs /dev devtmpfs rw,relatime,size=66063000k,nr_inodes=16515750,mode=755 0 0 devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0 tmpfs /dev/shm tmpfs rw,relatime 0 0 /dev/mapper/sysvg-lv_root / ext4 rw,relatime,barrier=1,data=ordered 0 0 /proc/bus/usb /proc/bus/usb usbfs rw,relatime 0 0 /dev/sda1 /boot ext4 rw,relatime,barrier=1,data=ordered 0 0 tmpfs /phptmp tmpfs rw,noatime,size=1048576k,nr_inodes=15728640,mode=777 0 0 tmpfs /wsdltmp tmpfs rw,noatime,size=1048576k,nr_inodes=15728640,mode=777 0 0 none /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0 cgroup /cgroup/cpuset cgroup rw,relatime,cpuset 0 0 cgroup /cgroup/cpu cgroup rw,relatime,cpu 0 0 cgroup /cgroup/cpuacct cgroup rw,relatime,cpuacct 0 0 cgroup /cgroup/memory cgroup rw,relatime,memory 0 0 cgroup /cgroup/devices cgroup rw,relatime,devices 0 0 cgroup /cgroup/freezer cgroup rw,relatime,freezer 0 0 cgroup /cgroup/net_cls cgroup rw,relatime,net_cls 0 0 cgroup /cgroup/blkio cgroup rw,relatime,blkio 0 0 /etc/glusterfs/glusterfs-www.vol /var/www fuse.glusterfs rw,relatime,user_id=0,group_id=0,default_permissions,allow_other,max_read=131072 0 0 /etc/glusterfs/glusterfs-upload.vol /var/upload fuse.glusterfs rw,relatime,user_id=0,group_id=0,default_permissions,allow_other,max_read=131072 0 0 sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0 172.17.39.78:/www /data/www nfs rw,relatime,vers=3,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp,port=38467,timeo=600,retrans=2,sec=sys,mountaddr=172.17.39.78,mountvers=3,mountport=38465,mountproto=tcp,local_lock=none,addr=172.17.39.78 0 0 Mount info: cat /proc/self/mountinfo 16 21 0:3 / /proc rw,relatime - proc proc rw 17 21 0:0 / /sys rw,relatime - sysfs sysfs rw 18 21 0:5 / /dev rw,relatime - devtmpfs devtmpfs rw,size=66063000k,nr_inodes=16515750,mode=755 19 18 0:11 / /dev/pts rw,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=000 20 18 0:16 / /dev/shm rw,relatime - tmpfs tmpfs rw 21 1 253:1 / / rw,relatime - ext4 /dev/mapper/sysvg-lv_root rw,barrier=1,data=ordered 22 16 0:15 / /proc/bus/usb rw,relatime - usbfs /proc/bus/usb rw 23 21 8:1 / /boot rw,relatime - ext4 /dev/sda1 rw,barrier=1,data=ordered 24 21 0:17 / /phptmp rw,noatime - tmpfs tmpfs rw,size=1048576k,nr_inodes=15728640,mode=777 25 21 0:18 / /wsdltmp rw,noatime - tmpfs tmpfs rw,size=1048576k,nr_inodes=15728640,mode=777 26 16 0:19 / /proc/sys/fs/binfmt_misc rw,relatime - binfmt_misc none rw 27 21 0:20 / /cgroup/cpuset rw,relatime - cgroup cgroup rw,cpuset 28 21 0:21 / /cgroup/cpu rw,relatime - cgroup cgroup rw,cpu 29 21 0:22 / /cgroup/cpuacct rw,relatime - cgroup cgroup rw,cpuacct 30 21 0:23 / /cgroup/memory rw,relatime - cgroup cgroup rw,memory 31 21 0:24 / /cgroup/devices rw,relatime - cgroup cgroup rw,devices 32 21 0:25 / /cgroup/freezer rw,relatime - cgroup cgroup rw,freezer 33 21 0:26 / /cgroup/net_cls rw,relatime - cgroup cgroup rw,net_cls 34 21 0:27 / /cgroup/blkio rw,relatime - cgroup cgroup rw,blkio 35 21 0:28 / /var/www rw,relatime - fuse.glusterfs /etc/glusterfs/glusterfs-www.vol rw,user_id=0,group_id=0,default_permissions,allow_other,max_read=131072 36 21 0:29 / /var/upload rw,relatime - fuse.glusterfs /etc/glusterfs/glusterfs-upload.vol rw,user_id=0,group_id=0,default_permissions,allow_other,max_read=131072 37 21 0:30 / /var/lib/nfs/rpc_pipefs rw,relatime - rpc_pipefs sunrpc rw 39 21 0:31 / /data/www rw,relatime - nfs 172.17.39.78:/www rw,vers=3,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp,port=38467,timeo=600,retrans=2,sec=sys,mountaddr=172.17.39.78,mountvers=3,mountport=38465,mountproto=tcp,local_lock=none,addr=172.17.39.78 GlusterFS config: cat /etc/glusterfs/glusterfs-www.vol volume remote1 type protocol/client option transport-type tcp option remote-host 172.17.39.71 option ping-timeout 10 option transport.socket.nodelay on # undocumented option for speed # http://gluster.org/pipermail/gluster-users/2009-September/003158.html option remote-subvolume /data/www end-volume volume remote2 type protocol/client option transport-type tcp option remote-host 172.17.39.72 option ping-timeout 10 option transport.socket.nodelay on # undocumented option for speed # http://gluster.org/pipermail/gluster-users/2009-September/003158.html option remote-subvolume /data/www end-volume volume remote3 type protocol/client option transport-type tcp option remote-host 172.17.39.73 option ping-timeout 10 option transport.socket.nodelay on # undocumented option for speed # http://gluster.org/pipermail/gluster-users/2009-September/003158.html option remote-subvolume /data/www end-volume volume remote4 type protocol/client option transport-type tcp option remote-host 172.17.39.74 option ping-timeout 10 option transport.socket.nodelay on # undocumented option for speed # http://gluster.org/pipermail/gluster-users/2009-September/003158.html option remote-subvolume /data/www end-volume volume replicate1 type cluster/replicate option lookup-unhashed off # off will reduce cpu usage, and network option local-volume-name 'hostname' subvolumes remote1 remote2 end-volume volume replicate2 type cluster/replicate option lookup-unhashed off # off will reduce cpu usage, and network option local-volume-name 'hostname' subvolumes remote3 remote4 end-volume volume distribute type cluster/distribute subvolumes replicate1 replicate2 end-volume volume iocache type performance/io-cache option cache-size 8192MB # default is 32MB subvolumes distribute end-volume volume writeback type performance/write-behind option cache-size 1024MB option window-size 1MB subvolumes iocache end-volume ### Add io-threads for parallel requisitions volume iothreads type performance/io-threads option thread-count 64 # default is 16 subvolumes writeback end-volume volume ra type performance/read-ahead option page-size 2MB option page-count 16 option force-atime-update no subvolumes iothreads end-volume

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  • 26 Days: Countdown to Oracle OpenWorld 2012

    - by Michael Snow
    Welcome to our countdown to Oracle OpenWorld! Oracle OpenWorld 2012 is just around the corner. In less than 26 days, San Francisco will be invaded by an expected 50,000 people from all over the world. Here on the Oracle WebCenter team, we’ve all been working to help make the experience a great one for all our WebCenter customers. For a sneak peak  – we’ll be spending this week giving you a teaser of what to look forward to if you are joining us in San Francisco from September 30th through October 4th. We have Oracle WebCenter sessions covering all topics imaginable. Take a look and use the tools we provide to build out your schedule in advance and reserve your seats in your favorite sessions.  That gives you plenty of time to plan for your week with us in San Francisco. If unfortunately, your boss denied your request to attend - there are still some ways that you can join in the experience virtually On-Demand. This year - we are expanding even more up North of Market Street and will be taking over Union Square as well. Check out this map of San Francisco to get a sense of how much of a footprint Oracle OpenWorld has grown to this year. With so much to see and so many sessions to learn from - its no wonder that people get excited. Add to that a good mix of fun and all of the possible WebCenter sessions you could attend - you won't want to sleep at all to take full advantage of such an opportunity. We'll also have our annual WebCenter Customer Appreciation reception - stay tuned this week for some more info on registration to make sure you'll be able to join us. If you've been following the America's Cup at all and believe in EXTREME PERFORMANCE you'll definitely want to take a look at this video from last year's OpenWorld Keynote. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Important OpenWorld Links:  Attendee / Presenters Toolkit Oracle Schedule Builder WebCenter Sessions (listed in the catalog under Fusion Middleware as "Portals, Sites, Content, and Collaboration" ) Oracle Music Festival - AMAZING Line up!!  Oracle Customer Appreciation Night -LOOK HERE!! Oracle OpenWorld LIVE On-Demand Here are all the WebCenter sessions broken down by day for your viewing pleasure. Monday, October 1st CON8885 - Simplify CRM Engagement with Contextual Collaboration Are your sales teams disconnected and disengaged? Do you want a tool for easily connecting expertise across your organization and providing visibility into the complete sales process? Do you want a way to enhance and retain organization knowledge? Oracle Social Network is the answer. Attend this session to learn how to make CRM easy, effective, and efficient for use across virtual sales teams. Also learn how Oracle Social Network can drive sales force collaboration with natural conversations throughout the sales cycle, promote sales team productivity through purposeful social networking without the noise, and build cross-team knowledge by integrating conversations with CRM and other business applications. CON8268 - Oracle WebCenter Strategy: Engaging Your Customers. Empowering Your Business Oracle WebCenter is a user engagement platform for social business, connecting people and information. Attend this session to learn about the Oracle WebCenter strategy, and understand where Oracle is taking the platform to help companies engage customers, empower employees, and enable partners. Business success starts with ensuring that everyone is engaged with the right people and the right information and can access what they need through the channel of their choice—Web, mobile, or social. Are you giving customers, employees, and partners the best-possible experience? Come learn how you can! ¶ HOL10208 - Add Social Capabilities to Your Enterprise Applications Oracle Social Network enables you to add real-time collaboration capabilities into your enterprise applications, so that conversations can happen directly within your business systems. In this hands-on lab, you will try out the Oracle Social Network product to collaborate with other attendees, using real-time conversations with document sharing capabilities. Next you will embed social capabilities into a sample Web-based enterprise application, using embedded UI components. Experts will also write simple REST-based integrations, using the Oracle Social Network API to programmatically create social interactions. ¶ CON8893 - Improve Employee Productivity with Intuitive and Social Work Environments Social technologies have already transformed the ways customers, employees, partners, and suppliers communicate and stay informed. Forward-thinking organizations today need technologies and infrastructures to help them advance to the next level and integrate social activities with business applications to deliver a user experience that simplifies business processes and enterprise application engagement. Attend this session to hear from an innovative Oracle Social Network customer and learn how you can improve productivity with intuitive and social work environments and empower your employees with innovative social tools to enable contextual access to content and dynamic personalization of solutions. ¶ CON8270 - Oracle WebCenter Content Strategy and Vision Oracle WebCenter provides a strategic content infrastructure for managing documents, images, e-mails, and rich media files. With a single repository, organizations can address any content use case, such as accounts payable, HR onboarding, document management, compliance, records management, digital asset management, or Website management. In this session, learn about future plans for how Oracle WebCenter will address new use cases as well as new integrations with Oracle Fusion Middleware and Oracle Applications, leveraging your investments by making your users more productive and error-free. ¶ CON8269 - Oracle WebCenter Sites Strategy and Vision Oracle’s Web experience management solution, Oracle WebCenter Sites, enables organizations to use the online channel to drive customer acquisition and brand loyalty. It helps marketers and business users easily create and manage contextually relevant, social, interactive online experiences across multiple channels on a global scale. In this session, learn about future plans for how Oracle WebCenter Sites will provide you with the tools, capabilities, and integrations you need in order to continue to address your customers’ evolving requirements for engaging online experiences and keep moving your business forward. ¶ CON8896 - Living with SharePoint SharePoint is a popular platform, but it’s not always the best fit for Oracle customers. In this session, you’ll discover the technical and nontechnical limitations and pitfalls of SharePoint and learn about Oracle alternatives for collaboration, portals, enterprise and Web content management, social computing, and application integration. The presentation shows you how to integrate with SharePoint when business or IT requirements dictate and covers cloud-based (Office 365) and on-premises versions of SharePoint. Presented by a former Microsoft director of SharePoint product management and backed by independent customer research, this session will prepare you to answer the question “Why don’t we just use SharePoint for that?’ the next time it comes up in your organization. ¶ CON7843 - Content-Enabling Enterprise Processes with Oracle WebCenter Organizations today continually strive to automate business processes, reduce costs, and improve efficiency. Many business processes are content-intensive and unstructured, requiring ad hoc collaboration, and distributed in nature, requiring many approvals and generating huge volumes of paper. In this session, learn how Oracle and SYSTIME have partnered to help a customer content-enable its enterprise with Oracle WebCenter Content and Oracle WebCenter Imaging 11g and integrate them with Oracle Applications. ¶ CON6114 - Tape Robotics’ Newest Superhero: Now Fueled by Oracle Software For small, midsize, and rapidly growing businesses that want the most energy-efficient, scalable storage infrastructure to meet their rapidly growing data demands, Oracle’s most recent addition to its award-winning tape portfolio leverages several pieces of Oracle software. With Oracle Linux, Oracle WebLogic, and Oracle Fusion Middleware tools, the library achieves a higher level of usability than previous products while offering customers a familiar interface for management, plus ease of use. This session examines the competitive advantages of the tape library and how Oracle software raises customer satisfaction. Learn how the combination of Oracle engineered systems, Oracle Secure Backup, and Oracle’s StorageTek tape libraries provide end-to-end coverage of your data. ¶ CON9437 - Mobile Access Management With more than five billion mobile devices on the planet and an increasing number of users using their own devices to access corporate data and applications, securely extending identity management to mobile devices has become a hot topic. This session focuses on how to extend your existing identity management infrastructure and policies to securely and seamlessly enable mobile user access. CON7815 - Customer Experience Online in Cloud: Oracle WebCenter Sites, Oracle ATG Apps, Oracle Exalogic Oracle WebCenter Sites and Oracle’s ATG product line together can provide a compelling marketing and e-commerce experience. When you couple them with the extreme performance of Oracle Exalogic, you’ll see unmatched scalability that provides you with a true cloud-based solution. In this session, you’ll learn how running Oracle WebCenter Sites and ATG applications on Oracle Exalogic delivers both a private and a public cloud experience. Find out what it takes to get these systems working together and delivering engaging Web experiences. Even if you aren’t considering Oracle Exalogic today, the rich Web experience of Oracle WebCenter, paired with the depth of the ATG product line, can provide your business full support, from merchandising through sale completion. ¶ CON8271 - Oracle WebCenter Portal Strategy and Vision To innovate and keep a competitive edge, organizations need to leverage the power of agile and responsive Web applications. Oracle WebCenter Portal enables you to do just that, by delivering intuitive user experiences for enterprise applications to drive innovation with composite applications and mashups. Attend this session to learn firsthand from customers how Oracle WebCenter Portal extends the value of existing enterprise applications, business processes, and content; delivers a superior business user experience; and maximizes limited IT resources. ¶ CON8880 - The Connected Customer Experience Begins with the Online Channel There’s a lot of talk these days about how to connect the customer journey across various touchpoints—from Websites and e-commerce to call centers and in-store—to provide experiences that are more relevant and engaging and ultimately gain competitive edge. Doing it all at once isn’t a realistic objective, so where do you start? Come to this session, and hear about three steps you can take that can help you begin your journey toward delivering the connected customer experience. You’ll hear how Oracle now has an integrated digital marketing platform for your corporate Website, your e-commerce site, your self-service portal, and your marketing and loyalty campaigns, and you’ll learn what you can do today to begin executing on your customer experience initiatives. ¶ GEN11451 - General Session: Building Mobile Applications with Oracle Cloud With the prevalence of smart mobile devices, companies are facing an increased demand to provide access to data and applications from new channels. However, developing applications for mobile devices poses some unique challenges. Come to this session to learn how Oracle addresses these challenges, offering a simpler way to develop and deploy cross-device mobile applications. See how Oracle Cloud enables you to access applications, data, and services from mobile channels in an easier way.  CON8272 - Oracle Social Network Strategy and Vision One key way of increasing employee productivity is by bringing people, processes, and information together—providing new social capabilities to enable business users to quickly correspond and collaborate on business activities. Oracle WebCenter provides a user engagement platform with social and collaborative technologies to empower business users to focus on their key business processes, applications, and content in the context of their role and process. Attend this session to hear how the latest social capabilities in Oracle Social Network are enabling organizations to transform themselves into social businesses.  --- Tuesday, October 2nd HOL10194 - Enterprise Content Management Simplified: Oracle WebCenter Content’s Next-Generation UI Regardless of the nature of your business, unstructured content underpins many of its daily functions. Whether you are working with traditional presentations, spreadsheets, or text documents—or even with digital assets such as images and multimedia files—your content needs to be accessible and manageable in convenient and intuitive ways to make working with the content easier. Additionally, you need the ability to easily share documents with coworkers to facilitate a collaborative working environment. Come to this session to see how Oracle WebCenter Content’s next-generation user interface helps modern knowledge workers easily manage personal and enterprise documents in a collaborative environment.¶ CON8877 - Develop a Mobile Strategy with Oracle WebCenter: Engage Customers, Employees, and Partners Mobile technology has gone from nice-to-have to a cornerstone of user engagement. Mobile access enables users to have information available at their fingertips, enabling them to take action the moment they make a decision, interact in the moment of convenience, and take advantage of new service offerings in their preferred channels. All your employees have your mobile applications in their pocket; now what are you going to do? It is a critical step for companies to think through what their employees, customers, and partners really need on their devices. Attend this session to see how Oracle WebCenter enables you to better engage your customers, employees, and partners by providing a unified experience across multiple channels. ¶ CON9447 - Enabling Access for Hundreds of Millions of Users How do you grow your business by identifying, authenticating, authorizing, and federating users on the Web, leveraging social identity and the open source OAuth protocol? How do you scale your access management solution to support hundreds of millions of users? With social identity support out of the box, Oracle’s access management solution is also benchmarked for 250-million-user deployment according to real-world customer scenarios. In this session, you will learn about the social identity capability and the 250-million-user benchmark testing of Oracle Access Manager and Oracle Adaptive Access Manager running on Oracle Exalogic and Oracle Exadata. ¶ HOL10207 - Build an Intranet Portal with Oracle WebCenter In this hands-on lab, you’ll work with Oracle WebCenter Portal and Oracle WebCenter Content to build out an enterprise portal that maximizes the productivity of teams and individual contributors. Using browser-based tools, you’ll manage site resources such as page styles, templates, and navigation. You’ll edit content stored in Oracle WebCenter Content directly from your portal. You’ll also experience the latest features that promote collaboration, social networking, and personal productivity. ¶ CON2906 - Get Proactive: Best Practices for Maintaining Oracle Fusion Middleware You chose Oracle Fusion Middleware products to help your organization deliver superior business results. Now learn how to take full advantage of your software with all the great tools, resources, and product updates you’re entitled to through Oracle Support. In this session, Oracle product experts provide proven best practices to help you work more efficiently, plan and prepare for upgrades and patching more effectively, and manage risk. Topics include configuration management tools, remote diagnostics, My Oracle Support Community, and My Oracle Support Lifecycle Advisors. New users and Oracle Fusion Middleware experts alike are guaranteed to leave with fresh ideas and practical, easy-to-implement next steps. ¶ CON8878 - Oracle WebCenter’s Cloud Strategy: From Social and Platform Services to Mashups Cloud computing represents a paradigm shift in how we build applications, automate processes, collaborate, and share and in how we secure our enterprise. Additionally, as you adopt cloud-based services in your organization, it’s likely that you will still have many critical on-premises applications running. With these mixed environments, multiple user interfaces, different security, and multiple datasources and content sources, how do you start evolving your strategy to account for these challenges? Oracle WebCenter offers a complete array of technologies enabling you to solve these challenges and prepare you for the cloud. Attend this session to learn how you can use Oracle WebCenter in the cloud as well as create on-premises and cloud application mash-ups. ¶ CON8901 - Optimize Enterprise Business Processes with Oracle WebCenter and Oracle BPM Do you have business processes that span multiple applications? Are you grappling with how to have visibility across these business processes; how to manage content that is associated with these processes; and, most importantly, how to model and optimize these business processes? Attend this session to hear how Oracle WebCenter and Oracle Business Process Management provide a unique set of integrated solutions to provide a composite application dashboard across these business processes and offer a solution for content-centric business processes. ¶ CON8883 - Deliver Engaging Interfaces to Oracle Applications with Oracle WebCenter Critical business processes live within enterprise applications, and application users need to manage and execute these processes as effectively as possible. Oracle provides a comprehensive user engagement platform to increase user productivity and optimize overall processes within Oracle Applications—Oracle E-Business Suite and Oracle’s Siebel, PeopleSoft, and JD Edwards product families—and third-party applications. Attend this session to learn how you can integrate these applications with Oracle WebCenter to deliver composite application dashboards to your end users—whether they are your customers, partners, or employees—for enhanced usability and Web 2.0–enabled enterprise portals.¶ Wednesday, October 3rd CON8895 - Future-Ready Intranets: How Aramark Re-engineered the Application Landscape There are essential techniques and technologies you can use to deliver employee portals that garner higher productivity, improve business efficiency, and increase user engagement. Attend this session to learn how you can leverage Oracle WebCenter Portal as a user engagement platform for bringing together business process management, enterprise content management, and business intelligence into a highly relevant and integrated experience. Hear how Aramark has leveraged Oracle WebCenter Portal and Oracle WebCenter Content to deliver a unified workspace providing simpler navigation and processing, consolidation of tools, easy access to information, integrated search, and single sign-on. ¶ CON8886 - Content Consolidation: Save Money, Increase Efficiency, and Eliminate Silos Organizations are looking for ways to save money and be more efficient. With content in many different places, it’s difficult to know where to look for a document and whether the document is the most current version. With Oracle WebCenter, content can be consolidated into one best-of-breed repository that is secure, scalable, and integrated with your business processes and applications. Users can find the content they need, where they need it, and ensure that it is the right content. This session covers content challenges that affect your business; content consolidation that can lead to savings in storage and administration costs and can lower risks; and how companies are realizing savings. ¶ CON8911 - Improve Online Experiences for Customers and Partners with Self-Service Portals Are you able to provide your customers and partners an easy-to-use online self-service experience? Are you processing high-volume transactions and struggling with call center bottlenecks or back-end systems that won’t integrate, causing order delays and customer frustration? Are you looking to target content such as product and service offerings to your end users? This session shares approaches to providing targeted delivery as well as strategies and best practices for transforming your business by providing an intuitive user experience for your customers and partners. ¶ CON6156 - Top 10 Ways to Integrate Oracle WebCenter Content This session covers 10 common ways to integrate Oracle WebCenter Content with other enterprise applications and middleware. It discusses out-of-the-box modules that provide expanded features in Oracle WebCenter Content—such as enterprise search, SOA, and BPEL—as well as developer tools you can use to create custom integrations. The presentation also gives guidance on which integration option may work best in your environment. ¶ HOL10207 - Build an Intranet Portal with Oracle WebCenter In this hands-on lab, you’ll work with Oracle WebCenter Portal and Oracle WebCenter Content to build out an enterprise portal that maximizes the productivity of teams and individual contributors. Using browser-based tools, you’ll manage site resources such as page styles, templates, and navigation. You’ll edit content stored in Oracle WebCenter Content directly from your portal. You’ll also experience the latest features that promote collaboration, social networking, and personal productivity. ¶ CON7817 - Migration to Oracle WebCenter Imaging 11g Customers today continually strive to automate business processes, reduce costs, and improve efficiency. The accounts payable process—which is often distributed in nature, requires many approvals, and generates huge volumes of paper invoices—is automated by many customers. In this session, learn how Oracle and SYSTIME have partnered to help a customer migrate its existing Oracle Imaging and Process Management Release 7.6 to the latest Oracle WebCenter Imaging 11g and integrate it with Oracle’s JD Edwards family of products. ¶ CON8910 - How to Engage Customers Across Web, Mobile, and Social Channels Whether on desktops at the office, on tablets at home, or on mobile phones when on the go, today’s customers are always connected. To engage today’s customers, you need to make the online customer experience connected and consistent across a host of devices and multiple channels, including Web, mobile, and social networks. Managing this multichannel environment can result in lots of headaches without the right tools. Attend this session to learn how Oracle WebCenter Sites solves the challenge of multichannel customer engagement. ¶ HOL10206 - Oracle WebCenter Sites 11g: Transforming the Content Contributor Experience Oracle WebCenter Sites 11g makes it easy for marketers and business users to contribute to and manage Websites with the new visual, contextual, and intuitive Web authoring interface. In this hands-on lab, you will create and manage content for a sports-themed Website, using many of the new and enhanced features of the 11g release. ¶ CON8900 - Building Next-Generation Portals: An Interactive Customer Panel Discussion Social and collaborative technologies have changed how people interact, learn, and collaborate, and providing a modern, social Web presence is imperative to remain competitive in today’s market. Can your business benefit from a more collaborative and interactive portal environment for employees, customers, and partners? Attend this session to hear from Oracle WebCenter Portal customers as they share their strategies and best practices for providing users with a modern experience that adapts to their needs and includes personalized access to content in context. The panel also addresses how customers have benefited from creating next-generation portals by migrating from older portal technologies to Oracle WebCenter Portal. ¶ CON9625 - Taking Control of Oracle WebCenter Security Organizations are increasingly looking to extend their Oracle WebCenter portal for social business, to serve external users and provide seamless access to the right information. In particular, many organizations are extending Oracle WebCenter in a business-to-business scenario requiring secure identification and authorization of business partners and their users. This session focuses on how customers are leveraging, securing, and providing access control to Oracle WebCenter portal and mobile solutions. You will learn best practices and hear real-world examples of how to provide flexible and granular access control for Oracle WebCenter deployments, using Oracle Platform Security Services and Oracle Access Management Suite product offerings. ¶ CON8891 - Extending Social into Enterprise Applications and Business Processes Oracle Social Network is an extensible social platform that enables contextual collaboration within enterprise applications and business processes, providing relevant data from across various enterprise systems in one place. Attend this session to see how an Oracle Social Network customer is integrating multiple applications—such as CRM, HCM, and business processes—into Oracle Social Network and Oracle WebCenter to enable individuals and teams to solve complex cross-organizational business problems more effectively by utilizing the social enterprise. ¶ Thursday, October 4th CON8899 - Becoming a Social Business: Stories from the Front Lines of Change What does it really mean to be a social business? How can you change our organization to embrace social approaches? What pitfalls do you need to avoid? In this lively panel discussion, customer and industry thought leaders in social business explore these topics and more as they share their stories of the good, the bad, and the ugly that can happen when embracing social methods and technologies to improve business success. Using moderated questions and open Q&A from the audience, the panel discusses vital topics such as the critical factors for success, the major issues to avoid, how to gain senior executive support for social efforts, how to handle undesired behavior, and how to measure business impact. It takes a thought-provoking look at becoming a social business from the inside. ¶ CON6851 - Oracle WebCenter and Oracle Business Intelligence Enterprise Edition to Create Vendor Portals Large manufacturers of grocery items routinely find themselves depending on the inventory management expertise of their wholesalers and distributors. Inventory costs can be managed more efficiently by the manufacturers if they have better insight into the inventory levels of items carried by their distributors. This creates a unique opportunity for distributors and wholesalers to leverage this knowledge into a revenue-generating subscription service. Oracle Business Intelligence Enterprise Edition and Oracle WebCenter Portal play a key part in enabling creation of business-managed business intelligence portals for vendors. This session discusses one customer that implemented this by leveraging Oracle WebCenter and Oracle Business Intelligence Enterprise Edition. ¶ CON8879 - Provide a Personalized and Consistent Customer Experience in Your Websites and Portals Your customers engage with your company online in different ways throughout their journey—from prospecting by acquiring information on your corporate Website to transacting through self-service applications on your customer portal—and then the cycle begins again when they look for new products and services. Ensuring that the customer experience is consistent and personalized across online properties—from branding and content to interactions and transactions—can be a daunting task. Oracle WebCenter enables you to speak and interact with your customers with one voice across your Websites and portals by providing an integrated platform for delivery of self-service and engagement that unifies and personalizes the online experience. Learn more in this session. ¶ CON8898 - Land Mines, Potholes, and Dirt Roads: Navigating the Way to ECM Nirvana Ten years ago, people were predicting that by this time in history, we’d be some kind of utopian paperless society. As we all know, we’re not there yet, but are we getting closer? What is keeping companies from driving down the road to enterprise content management bliss? Most people understand that using ECM as a central platform enables organizations to expedite document-centric processes, but most business processes in organizations are still heavily paper-based. Many of these processes could be automated and improved with an ECM platform infrastructure. In this panel discussion, you’ll hear from Oracle WebCenter customers that have already solved some of these challenges as they share their strategies for success and roads to avoid along your journey. ¶ CON8908 - Oracle WebCenter Portal: Creating and Using Content Presenter Templates Oracle WebCenter Portal applications use task flows to display and integrate content stored in the Oracle WebCenter Content server. Among the most flexible task flows is Content Presenter, which renders various types of content on an Oracle WebCenter Portal page. Although Oracle WebCenter Portal comes with a set of predefined Content Presenter templates, developers can create their own templates for specific rendering needs. This session shows the lifecycle of developing Content Presenter task flows, including how to create, package, import, modify at runtime, and use such templates. In addition to simple examples with Oracle Application Development Framework (Oracle ADF) UI elements to render the content, it shows how to use other UI technologies, CSS files, and JavaScript libraries. ¶ CON8897 - Using Web Experience Management to Drive Online Marketing Success Every year, the online channel becomes more imperative for driving organizational top-line revenue, but for many companies, mastering how to best market their products and services in a fast-evolving online world with high customer expectations for personalized experiences can be a complex proposition. Come to this panel discussion, and hear directly from online marketers how they are succeeding today by using Web experience management to drive marketing success, using capabilities such as targeting and optimization, user-generated content, mobile site publishing, and site visitor personalization to deliver engaging online experiences. ¶ CON8892 - Oracle’s Journey to Social Business Social business is a revolution, one that is causing rapidly accelerating change in how companies and customers engage with one another and how employees work together. Oracle’s goal in becoming a social business is to create a socially connected organization in which working collaboratively across geographical locations, lines of business, and management chains is second nature, enabling innovative solutions to business challenges. We can achieve this by connecting the right people, finding the right content, communicating with the right people, collaborating at the right time, and building the right communities in the right context—all ready in the CLOUD. Attend this session to see how Oracle is transforming itself into a social business. ¶  ------------ If you've read all the way to the end here - we are REALLY looking forward to seeing you in San Francisco.

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  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "\n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • AngularJS on top of ASP.NET: Moving the MVC framework out to the browser

    - by Varun Chatterji
    Heavily drawing inspiration from Ruby on Rails, MVC4’s convention over configuration model of development soon became the Holy Grail of .NET web development. The MVC model brought with it the goodness of proper separation of concerns between business logic, data, and the presentation logic. However, the MVC paradigm, was still one in which server side .NET code could be mixed with presentation code. The Razor templating engine, though cleaner than its predecessors, still encouraged and allowed you to mix .NET server side code with presentation logic. Thus, for example, if the developer required a certain <div> tag to be shown if a particular variable ShowDiv was true in the View’s model, the code could look like the following: Fig 1: To show a div or not. Server side .NET code is used in the View Mixing .NET code with HTML in views can soon get very messy. Wouldn’t it be nice if the presentation layer (HTML) could be pure HTML? Also, in the ASP.NET MVC model, some of the business logic invariably resides in the controller. It is tempting to use an anti­pattern like the one shown above to control whether a div should be shown or not. However, best practice would indicate that the Controller should not be aware of the div. The ShowDiv variable in the model should not exist. A controller should ideally, only be used to do the plumbing of getting the data populated in the model and nothing else. The view (ideally pure HTML) should render the presentation layer based on the model. In this article we will see how Angular JS, a new JavaScript framework by Google can be used effectively to build web applications where: 1. Views are pure HTML 2. Controllers (in the server sense) are pure REST based API calls 3. The presentation layer is loaded as needed from partial HTML only files. What is MVVM? MVVM short for Model View View Model is a new paradigm in web development. In this paradigm, the Model and View stuff exists on the client side through javascript instead of being processed on the server through postbacks. These frameworks are JavaScript frameworks that facilitate the clear separation of the “frontend” or the data rendering logic from the “backend” which is typically just a REST based API that loads and processes data through a resource model. The frameworks are called MVVM as a change to the Model (through javascript) gets reflected in the view immediately i.e. Model > View. Also, a change on the view (through manual input) gets reflected in the model immediately i.e. View > Model. The following figure shows this conceptually (comments are shown in red): Fig 2: Demonstration of MVVM in action In Fig 2, two text boxes are bound to the same variable model.myInt. Thus, changing the view manually (changing one text box through keyboard input) also changes the other textbox in real time demonstrating V > M property of a MVVM framework. Furthermore, clicking the button adds 1 to the value of model.myInt thus changing the model through JavaScript. This immediately updates the view (the value in the two textboxes) thus demonstrating the M > V property of a MVVM framework. Thus we see that the model in a MVVM JavaScript framework can be regarded as “the single source of truth“. This is an important concept. Angular is one such MVVM framework. We shall use it to build a simple app that sends SMS messages to a particular number. Application, Routes, Views, Controllers, Scope and Models Angular can be used in many ways to construct web applications. For this article, we shall only focus on building Single Page Applications (SPAs). Many of the approaches we will follow in this article have alternatives. It is beyond the scope of this article to explain every nuance in detail but we shall try to touch upon the basic concepts and end up with a working application that can be used to send SMS messages using Sent.ly Plus (a service that is itself built using Angular). Before you read on, we would like to urge you to forget what you know about Models, Views, Controllers and Routes in the ASP.NET MVC4 framework. All these words have different meanings in the Angular world. Whenever these words are used in this article, they will refer to Angular concepts and not ASP.NET MVC4 concepts. The following figure shows the skeleton of the root page of an SPA: Fig 3: The skeleton of a SPA The skeleton of the application is based on the Bootstrap starter template which can be found at: http://getbootstrap.com/examples/starter­template/ Apart from loading the Angular, jQuery and Bootstrap JavaScript libraries, it also loads our custom scripts /app/js/controllers.js /app/js/app.js These scripts define the routes, views and controllers which we shall come to in a moment. Application Notice that the body tag (Fig. 3) has an extra attribute: ng­app=”smsApp” Providing this tag “bootstraps” our single page application. It tells Angular to load a “module” called smsApp. This “module” is defined /app/js/app.js angular.module('smsApp', ['smsApp.controllers', function () {}]) Fig 4: The definition of our application module The line shows above, declares a module called smsApp. It also declares that this module “depends” on another module called “smsApp.controllers”. The smsApp.controllers module will contain all the controllers for our SPA. Routing and Views Notice that in the Navbar (in Fig 3) we have included two hyperlinks to: “#/app” “#/help” This is how Angular handles routing. Since the URLs start with “#”, they are actually just bookmarks (and not server side resources). However, our route definition (in /app/js/app.js) gives these URLs a special meaning within the Angular framework. angular.module('smsApp', ['smsApp.controllers', function () { }]) //Configure the routes .config(['$routeProvider', function ($routeProvider) { $routeProvider.when('/binding', { templateUrl: '/app/partials/bindingexample.html', controller: 'BindingController' }); }]); Fig 5: The definition of a route with an associated partial view and controller As we can see from the previous code sample, we are using the $routeProvider object in the configuration of our smsApp module. Notice how the code “asks for” the $routeProvider object by specifying it as a dependency in the [] braces and then defining a function that accepts it as a parameter. This is known as dependency injection. Please refer to the following link if you want to delve into this topic: http://docs.angularjs.org/guide/di What the above code snippet is doing is that it is telling Angular that when the URL is “#/binding”, then it should load the HTML snippet (“partial view”) found at /app/partials/bindingexample.html. Also, for this URL, Angular should load the controller called “BindingController”. We have also marked the div with the class “container” (in Fig 3) with the ng­view attribute. This attribute tells Angular that views (partial HTML pages) defined in the routes will be loaded within this div. You can see that the Angular JavaScript framework, unlike many other frameworks, works purely by extending HTML tags and attributes. It also allows you to extend HTML with your own tags and attributes (through directives) if you so desire, you can find out more about directives at the following URL: http://www.codeproject.com/Articles/607873/Extending­HTML­with­AngularJS­Directives Controllers and Models We have seen how we define what views and controllers should be loaded for a particular route. Let us now consider how controllers are defined. Our controllers are defined in the file /app/js/controllers.js. The following snippet shows the definition of the “BindingController” which is loaded when we hit the URL http://localhost:port/index.html#/binding (as we have defined in the route earlier as shown in Fig 5). Remember that we had defined that our application module “smsApp” depends on the “smsApp.controllers” module (see Fig 4). The code snippet below shows how the “BindingController” defined in the route shown in Fig 5 is defined in the module smsApp.controllers: angular.module('smsApp.controllers', [function () { }]) .controller('BindingController', ['$scope', function ($scope) { $scope.model = {}; $scope.model.myInt = 6; $scope.addOne = function () { $scope.model.myInt++; } }]); Fig 6: The definition of a controller in the “smsApp.controllers” module. The pieces are falling in place! Remember Fig.2? That was the code of a partial view that was loaded within the container div of the skeleton SPA shown in Fig 3. The route definition shown in Fig 5 also defined that the controller called “BindingController” (shown in Fig 6.) was loaded when we loaded the URL: http://localhost:22544/index.html#/binding The button in Fig 2 was marked with the attribute ng­click=”addOne()” which added 1 to the value of model.myInt. In Fig 6, we can see that this function is actually defined in the “BindingController”. Scope We can see from Fig 6, that in the definition of “BindingController”, we defined a dependency on $scope and then, as usual, defined a function which “asks for” $scope as per the dependency injection pattern. So what is $scope? Any guesses? As you might have guessed a scope is a particular “address space” where variables and functions may be defined. This has a similar meaning to scope in a programming language like C#. Model: The Scope is not the Model It is tempting to assign variables in the scope directly. For example, we could have defined myInt as $scope.myInt = 6 in Fig 6 instead of $scope.model.myInt = 6. The reason why this is a bad idea is that scope in hierarchical in Angular. Thus if we were to define a controller which was defined within the another controller (nested controllers), then the inner controller would inherit the scope of the parent controller. This inheritance would follow JavaScript prototypal inheritance. Let’s say the parent controller defined a variable through $scope.myInt = 6. The child controller would inherit the scope through java prototypical inheritance. This basically means that the child scope has a variable myInt that points to the parent scopes myInt variable. Now if we assigned the value of myInt in the parent, the child scope would be updated with the same value as the child scope’s myInt variable points to the parent scope’s myInt variable. However, if we were to assign the value of the myInt variable in the child scope, then the link of that variable to the parent scope would be broken as the variable myInt in the child scope now points to the value 6 and not to the parent scope’s myInt variable. But, if we defined a variable model in the parent scope, then the child scope will also have a variable model that points to the model variable in the parent scope. Updating the value of $scope.model.myInt in the parent scope would change the model variable in the child scope too as the variable is pointed to the model variable in the parent scope. Now changing the value of $scope.model.myInt in the child scope would ALSO change the value in the parent scope. This is because the model reference in the child scope is pointed to the scope variable in the parent. We did no new assignment to the model variable in the child scope. We only changed an attribute of the model variable. Since the model variable (in the child scope) points to the model variable in the parent scope, we have successfully changed the value of myInt in the parent scope. Thus the value of $scope.model.myInt in the parent scope becomes the “single source of truth“. This is a tricky concept, thus it is considered good practice to NOT use scope inheritance. More info on prototypal inheritance in Angular can be found in the “JavaScript Prototypal Inheritance” section at the following URL: https://github.com/angular/angular.js/wiki/Understanding­Scopes. Building It: An Angular JS application using a .NET Web API Backend Now that we have a perspective on the basic components of an MVVM application built using Angular, let’s build something useful. We will build an application that can be used to send out SMS messages to a given phone number. The following diagram describes the architecture of the application we are going to build: Fig 7: Broad application architecture We are going to add an HTML Partial to our project. This partial will contain the form fields that will accept the phone number and message that needs to be sent as an SMS. It will also display all the messages that have previously been sent. All the executable code that is run on the occurrence of events (button clicks etc.) in the view resides in the controller. The controller interacts with the ASP.NET WebAPI to get a history of SMS messages, add a message etc. through a REST based API. For the purposes of simplicity, we will use an in memory data structure for the purposes of creating this application. Thus, the tasks ahead of us are: Creating the REST WebApi with GET, PUT, POST, DELETE methods. Creating the SmsView.html partial Creating the SmsController controller with methods that are called from the SmsView.html partial Add a new route that loads the controller and the partial. 1. Creating the REST WebAPI This is a simple task that should be quite straightforward to any .NET developer. The following listing shows our ApiController: public class SmsMessage { public string to { get; set; } public string message { get; set; } } public class SmsResource : SmsMessage { public int smsId { get; set; } } public class SmsResourceController : ApiController { public static Dictionary<int, SmsResource> messages = new Dictionary<int, SmsResource>(); public static int currentId = 0; // GET api/<controller> public List<SmsResource> Get() { List<SmsResource> result = new List<SmsResource>(); foreach (int key in messages.Keys) { result.Add(messages[key]); } return result; } // GET api/<controller>/5 public SmsResource Get(int id) { if (messages.ContainsKey(id)) return messages[id]; return null; } // POST api/<controller> public List<SmsResource> Post([FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { SmsResource res = (SmsResource) value; res.smsId = currentId++; messages.Add(res.smsId, res); //SentlyPlusSmsSender.SendMessage(value.to, value.message); return Get(); } } // PUT api/<controller>/5 public List<SmsResource> Put(int id, [FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { if (messages.ContainsKey(id)) { //Update the message messages[id].message = value.message; messages[id].to = value.message; } return Get(); } } // DELETE api/<controller>/5 public List<SmsResource> Delete(int id) { if (messages.ContainsKey(id)) { messages.Remove(id); } return Get(); } } Once this class is defined, we should be able to access the WebAPI by a simple GET request using the browser: http://localhost:port/api/SmsResource Notice the commented line: //SentlyPlusSmsSender.SendMessage The SentlyPlusSmsSender class is defined in the attached solution. We have shown this line as commented as we want to explain the core Angular concepts. If you load the attached solution, this line is uncommented in the source and an actual SMS will be sent! By default, the API returns XML. For consumption of the API in Angular, we would like it to return JSON. To change the default to JSON, we make the following change to WebApiConfig.cs file located in the App_Start folder. public static class WebApiConfig { public static void Register(HttpConfiguration config) { config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); var appXmlType = config.Formatters.XmlFormatter. SupportedMediaTypes. FirstOrDefault( t => t.MediaType == "application/xml"); config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType); } } We now have our backend REST Api which we can consume from Angular! 2. Creating the SmsView.html partial This simple partial will define two fields: the destination phone number (international format starting with a +) and the message. These fields will be bound to model.phoneNumber and model.message. We will also add a button that we shall hook up to sendMessage() in the controller. A list of all previously sent messages (bound to model.allMessages) will also be displayed below the form input. The following code shows the code for the partial: <!--­­ If model.errorMessage is defined, then render the error div -­­> <div class="alert alert-­danger alert-­dismissable" style="margin­-top: 30px;" ng­-show="model.errorMessage != undefined"> <button type="button" class="close" data­dismiss="alert" aria­hidden="true">&times;</button> <strong>Error!</strong> <br /> {{ model.errorMessage }} </div> <!--­­ The input fields bound to the model --­­> <div class="well" style="margin-­top: 30px;"> <table style="width: 100%;"> <tr> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Phone number (eg; +44 7778 609466)" ng­-model="model.phoneNumber" class="form-­control" style="width: 90%" onkeypress="return checkPhoneInput();" /> </td> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Message" ng­-model="model.message" class="form-­control" style="width: 90%" /> </td> <td style="text-­align: center;"> <button class="btn btn-­danger" ng-­click="sendMessage();" ng-­disabled="model.isAjaxInProgress" style="margin­right: 5px;">Send</button> <img src="/Content/ajax-­loader.gif" ng­-show="model.isAjaxInProgress" /> </td> </tr> </table> </div> <!--­­ The past messages ­­--> <div style="margin-­top: 30px;"> <!­­-- The following div is shown if there are no past messages --­­> <div ng­-show="model.allMessages.length == 0"> No messages have been sent yet! </div> <!--­­ The following div is shown if there are some past messages --­­> <div ng-­show="model.allMessages.length == 0"> <table style="width: 100%;" class="table table-­striped"> <tr> <td>Phone Number</td> <td>Message</td> <td></td> </tr> <!--­­ The ng-­repeat directive is line the repeater control in .NET, but as you can see this partial is pure HTML which is much cleaner --> <tr ng-­repeat="message in model.allMessages"> <td>{{ message.to }}</td> <td>{{ message.message }}</td> <td> <button class="btn btn-­danger" ng-­click="delete(message.smsId);" ng­-disabled="model.isAjaxInProgress">Delete</button> </td> </tr> </table> </div> </div> The above code is commented and should be self explanatory. Conditional rendering is achieved through using the ng-­show=”condition” attribute on various div tags. Input fields are bound to the model and the send button is bound to the sendMessage() function in the controller as through the ng­click=”sendMessage()” attribute defined on the button tag. While AJAX calls are taking place, the controller sets model.isAjaxInProgress to true. Based on this variable, buttons are disabled through the ng-­disabled directive which is added as an attribute to the buttons. The ng-­repeat directive added as an attribute to the tr tag causes the table row to be rendered multiple times much like an ASP.NET repeater. 3. Creating the SmsController controller The penultimate piece of our application is the controller which responds to events from our view and interacts with our MVC4 REST WebAPI. The following listing shows the code we need to add to /app/js/controllers.js. Note that controller definitions can be chained. Also note that this controller “asks for” the $http service. The $http service is a simple way in Angular to do AJAX. So far we have only encountered modules, controllers, views and directives in Angular. The $http is new entity in Angular called a service. More information on Angular services can be found at the following URL: http://docs.angularjs.org/guide/dev_guide.services.understanding_services. .controller('SmsController', ['$scope', '$http', function ($scope, $http) { //We define the model $scope.model = {}; //We define the allMessages array in the model //that will contain all the messages sent so far $scope.model.allMessages = []; //The error if any $scope.model.errorMessage = undefined; //We initially load data so set the isAjaxInProgress = true; $scope.model.isAjaxInProgress = true; //Load all the messages $http({ url: '/api/smsresource', method: "GET" }). success(function (data, status, headers, config) { this callback will be called asynchronously //when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { //called asynchronously if an error occurs //or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); $scope.delete = function (id) { //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource/' + id, method: "DELETE" }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } $scope.sendMessage = function () { $scope.model.errorMessage = undefined; var message = ''; if($scope.model.message != undefined) message = $scope.model.message.trim(); if ($scope.model.phoneNumber == undefined || $scope.model.phoneNumber == '' || $scope.model.phoneNumber.length < 10 || $scope.model.phoneNumber[0] != '+') { $scope.model.errorMessage = "You must enter a valid phone number in international format. Eg: +44 7778 609466"; return; } if (message.length == 0) { $scope.model.errorMessage = "You must specify a message!"; return; } //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource', method: "POST", data: { to: $scope.model.phoneNumber, message: $scope.model.message } }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status // We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } }]); We can see from the previous listing how the functions that are called from the view are defined in the controller. It should also be evident how easy it is to make AJAX calls to consume our MVC4 REST WebAPI. Now we are left with the final piece. We need to define a route that associates a particular path with the view we have defined and the controller we have defined. 4. Add a new route that loads the controller and the partial This is the easiest part of the puzzle. We simply define another route in the /app/js/app.js file: $routeProvider.when('/sms', { templateUrl: '/app/partials/smsview.html', controller: 'SmsController' }); Conclusion In this article we have seen how much of the server side functionality in the MVC4 framework can be moved to the browser thus delivering a snappy and fast user interface. We have seen how we can build client side HTML only views that avoid the messy syntax offered by server side Razor views. We have built a functioning app from the ground up. The significant advantage of this approach to building web apps is that the front end can be completely platform independent. Even though we used ASP.NET to create our REST API, we could just easily have used any other language such as Node.js, Ruby etc without changing a single line of our front end code. Angular is a rich framework and we have only touched on basic functionality required to create a SPA. For readers who wish to delve further into the Angular framework, we would recommend the following URL as a starting point: http://docs.angularjs.org/misc/started. To get started with the code for this project: Sign up for an account at http://plus.sent.ly (free) Add your phone number Go to the “My Identies Page” Note Down your Sender ID, Consumer Key and Consumer Secret Download the code for this article at: https://docs.google.com/file/d/0BzjEWqSE31yoZjZlV0d0R2Y3eW8/edit?usp=sharing Change the values of Sender Id, Consumer Key and Consumer Secret in the web.config file Run the project through Visual Studio!

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  • What&rsquo;s New in ASP.NET 4.0 Part Two: WebForms and Visual Studio Enhancements

    - by Rick Strahl
    In the last installment I talked about the core changes in the ASP.NET runtime that I’ve been taking advantage of. In this column, I’ll cover the changes to the Web Forms engine and some of the cool improvements in Visual Studio that make Web and general development easier. WebForms The WebForms engine is the area that has received most significant changes in ASP.NET 4.0. Probably the most widely anticipated features are related to managing page client ids and of ViewState on WebForm pages. Take Control of Your ClientIDs Unique ClientID generation in ASP.NET has been one of the most complained about “features” in ASP.NET. Although there’s a very good technical reason for these unique generated ids - they guarantee unique ids for each and every server control on a page - these unique and generated ids often get in the way of client-side JavaScript development and CSS styling as it’s often inconvenient and fragile to work with the long, generated ClientIDs. In ASP.NET 4.0 you can now specify an explicit client id mode on each control or each naming container parent control to control how client ids are generated. By default, ASP.NET generates mangled client ids for any control contained in a naming container (like a Master Page, or a User Control for example). The key to ClientID management in ASP.NET 4.0 are the new ClientIDMode and ClientIDRowSuffix properties. ClientIDMode supports four different ClientID generation settings shown below. For the following examples, imagine that you have a Textbox control named txtName inside of a master page control container on a WebForms page. <%@Page Language="C#"      MasterPageFile="~/Site.Master"     CodeBehind="WebForm2.aspx.cs"     Inherits="WebApplication1.WebForm2"  %> <asp:Content ID="content"  ContentPlaceHolderID="content"               runat="server"               ClientIDMode="Static" >       <asp:TextBox runat="server" ID="txtName" /> </asp:Content> The four available ClientIDMode values are: AutoID This is the existing behavior in ASP.NET 1.x-3.x where full naming container munging takes place. <input name="ctl00$content$txtName" type="text"        id="ctl00_content_txtName" /> This should be familiar to any ASP.NET developer and results in fairly unpredictable client ids that can easily change if the containership hierarchy changes. For example, removing the master page changes the name in this case, so if you were to move a block of script code that works against the control to a non-Master page, the script code immediately breaks. Static This option is the most deterministic setting that forces the control’s ClientID to use its ID value directly. No naming container naming at all is applied and you end up with clean client ids: <input name="ctl00$content$txtName"         type="text" id="txtName" /> Note that the name property which is used for postback variables to the server still is munged, but the ClientID property is displayed simply as the ID value that you have assigned to the control. This option is what most of us want to use, but you have to be clear on that because it can potentially cause conflicts with other controls on the page. If there are several instances of the same naming container (several instances of the same user control for example) there can easily be a client id naming conflict. Note that if you assign Static to a data-bound control, like a list child control in templates, you do not get unique ids either, so for list controls where you rely on unique id for child controls, you’ll probably want to use Predictable rather than Static. I’ll write more on this a little later when I discuss ClientIDRowSuffix. Predictable The previous two values are pretty self-explanatory. Predictable however, requires some explanation. To me at least it’s not in the least bit predictable. MSDN defines this value as follows: This algorithm is used for controls that are in data-bound controls. The ClientID value is generated by concatenating the ClientID value of the parent naming container with the ID value of the control. If the control is a data-bound control that generates multiple rows, the value of the data field specified in the ClientIDRowSuffix property is added at the end. For the GridView control, multiple data fields can be specified. If the ClientIDRowSuffix property is blank, a sequential number is added at the end instead of a data-field value. Each segment is separated by an underscore character (_). The key that makes this value a bit confusing is that it relies on the parent NamingContainer’s ClientID to build its own ClientID value. This effectively means that the value is not predictable at all but rather very tightly coupled to the parent naming container’s ClientIDMode setting. For my simple textbox example, if the ClientIDMode property of the parent naming container (Page in this case) is set to “Predictable” you’ll get this: <input name="ctl00$content$txtName" type="text"         id="content_txtName" /> which gives an id that based on walking up to the currently active naming container (the MasterPage content container) and starting the id formatting from there downward. Think of this as a semi unique name that’s guaranteed unique only for the naming container. If, on the other hand, the Page is set to “AutoID” you get the following with Predictable on txtName: <input name="ctl00$content$txtName" type="text"         id="ctl00_content_txtName" /> The latter is effectively the same as if you specified AutoID because it inherits the AutoID naming from the Page and Content Master Page control of the page. But again - predictable behavior always depends on the parent naming container and how it generates its id, so the id may not always be exactly the same as the AutoID generated value because somewhere in the NamingContainer chain the ClientIDMode setting may be set to a different value. For example, if you had another naming container in the middle that was set to Static you’d end up effectively with an id that starts with the NamingContainers id rather than the whole ctl000_content munging. The most common use for Predictable is likely to be for data-bound controls, which results in each data bound item getting a unique ClientID. Unfortunately, even here the behavior can be very unpredictable depending on which data-bound control you use - I found significant differences in how template controls in a GridView behave from those that are used in a ListView control. For example, GridView creates clean child ClientIDs, while ListView still has a naming container in the ClientID, presumably because of the template container on which you can’t set ClientIDMode. Predictable is useful, but only if all naming containers down the chain use this setting. Otherwise you’re right back to the munged ids that are pretty unpredictable. Another property, ClientIDRowSuffix, can be used in combination with ClientIDMode of Predictable to force a suffix onto list client controls. For example: <asp:GridView runat="server" ID="gvItems"              AutoGenerateColumns="false"             ClientIDMode="Static"              ClientIDRowSuffix="Id">     <Columns>     <asp:TemplateField>         <ItemTemplate>             <asp:Label runat="server" id="txtName"                        Text='<%# Eval("Name") %>'                   ClientIDMode="Predictable"/>         </ItemTemplate>     </asp:TemplateField>     <asp:TemplateField>         <ItemTemplate>         <asp:Label runat="server" id="txtId"                     Text='<%# Eval("Id") %>'                     ClientIDMode="Predictable" />         </ItemTemplate>     </asp:TemplateField>     </Columns>  </asp:GridView> generates client Ids inside of a column in the master page described earlier: <td>     <span id="txtName_0">Rick</span> </td> where the value after the underscore is the ClientIDRowSuffix field - in this case “Id” of the item data bound to the control. Note that all of the child controls require ClientIDMode=”Predictable” in order for the ClientIDRowSuffix to be applied, and the parent GridView controls need to be set to Static either explicitly or via Naming Container inheritance to give these simple names. It’s a bummer that ClientIDRowSuffix doesn’t work with Static to produce this automatically. Another real problem is that other controls process the ClientIDMode differently. For example, a ListView control processes the Predictable ClientIDMode differently and produces the following with the Static ListView and Predictable child controls: <span id="ctrl0_txtName_0">Rick</span> I couldn’t even figure out a way using ClientIDMode to get a simple ID that also uses a suffix short of falling back to manually generated ids using <%= %> expressions instead. Given the inconsistencies inside of list controls using <%= %>, ids for the ListView might not be a bad idea anyway. Inherit The final setting is Inherit, which is the default for all controls except Page. This means that controls by default inherit the parent naming container’s ClientIDMode setting. For more detailed information on ClientID behavior and different scenarios you can check out a blog post of mine on this subject: http://www.west-wind.com/weblog/posts/54760.aspx. ClientID Enhancements Summary The ClientIDMode property is a welcome addition to ASP.NET 4.0. To me this is probably the most useful WebForms feature as it allows me to generate clean IDs simply by setting ClientIDMode="Static" on either the page or inside of Web.config (in the Pages section) which applies the setting down to the entire page which is my 95% scenario. For the few cases when it matters - for list controls and inside of multi-use user controls or custom server controls) - I can use Predictable or even AutoID to force controls to unique names. For application-level page development, this is easy to accomplish and provides maximum usability for working with client script code against page controls. ViewStateMode Another area of large criticism for WebForms is ViewState. ViewState is used internally by ASP.NET to persist page-level changes to non-postback properties on controls as pages post back to the server. It’s a useful mechanism that works great for the overall mechanics of WebForms, but it can also cause all sorts of overhead for page operation as ViewState can very quickly get out of control and consume huge amounts of bandwidth in your page content. ViewState can also wreak havoc with client-side scripting applications that modify control properties that are tracked by ViewState, which can produce very unpredictable results on a Postback after client-side updates. Over the years in my own development, I’ve often turned off ViewState on pages to reduce overhead. Yes, you lose some functionality, but you can easily implement most of the common functionality in non-ViewState workarounds. Relying less on heavy ViewState controls and sticking with simpler controls or raw HTML constructs avoids getting around ViewState problems. In ASP.NET 3.x and prior, it wasn’t easy to control ViewState - you could turn it on or off and if you turned it off at the page or web.config level, you couldn’t turn it back on for specific controls. In short, it was an all or nothing approach. With ASP.NET 4.0, the new ViewStateMode property gives you more control. It allows you to disable ViewState globally either on the page or web.config level and then turn it back on for specific controls that might need it. ViewStateMode only works when EnableViewState="true" on the page or web.config level (which is the default). You can then use ViewStateMode of Disabled, Enabled or Inherit to control the ViewState settings on the page. If you’re shooting for minimal ViewState usage, the ideal situation is to set ViewStateMode to disabled on the Page or web.config level and only turn it back on particular controls: <%@Page Language="C#"      CodeBehind="WebForm2.aspx.cs"     Inherits="Westwind.WebStore.WebForm2"        ClientIDMode="Static"                ViewStateMode="Disabled"     EnableViewState="true"  %> <!-- this control has viewstate  --> <asp:TextBox runat="server" ID="txtName"  ViewStateMode="Enabled" />       <!-- this control has no viewstate - it inherits  from parent container --> <asp:TextBox runat="server" ID="txtAddress" /> Note that the EnableViewState="true" at the Page level isn’t required since it’s the default, but it’s important that the value is true. ViewStateMode has no effect if EnableViewState="false" at the page level. The main benefit of ViewStateMode is that it allows you to more easily turn off ViewState for most of the page and enable only a few key controls that might need it. For me personally, this is a perfect combination as most of my WebForm apps can get away without any ViewState at all. But some controls - especially third party controls - often don’t work well without ViewState enabled, and now it’s much easier to selectively enable controls rather than the old way, which required you to pretty much turn off ViewState for all controls that you didn’t want ViewState on. Inline HTML Encoding HTML encoding is an important feature to prevent cross-site scripting attacks in data entered by users on your site. In order to make it easier to create HTML encoded content, ASP.NET 4.0 introduces a new Expression syntax using <%: %> to encode string values. The encoding expression syntax looks like this: <%: "<script type='text/javascript'>" +     "alert('Really?');</script>" %> which produces properly encoded HTML: &lt;script type=&#39;text/javascript&#39; &gt;alert(&#39;Really?&#39;);&lt;/script&gt; Effectively this is a shortcut to: <%= HttpUtility.HtmlEncode( "<script type='text/javascript'>" + "alert('Really?');</script>") %> Of course the <%: %> syntax can also evaluate expressions just like <%= %> so the more common scenario applies this expression syntax against data your application is displaying. Here’s an example displaying some data model values: <%: Model.Address.Street %> This snippet shows displaying data from your application’s data store or more importantly, from data entered by users. Anything that makes it easier and less verbose to HtmlEncode text is a welcome addition to avoid potential cross-site scripting attacks. Although I listed Inline HTML Encoding here under WebForms, anything that uses the WebForms rendering engine including ASP.NET MVC, benefits from this feature. ScriptManager Enhancements The ASP.NET ScriptManager control in the past has introduced some nice ways to take programmatic and markup control over script loading, but there were a number of shortcomings in this control. The ASP.NET 4.0 ScriptManager has a number of improvements that make it easier to control script loading and addresses a few of the shortcomings that have often kept me from using the control in favor of manual script loading. The first is the AjaxFrameworkMode property which finally lets you suppress loading the ASP.NET AJAX runtime. Disabled doesn’t load any ASP.NET AJAX libraries, but there’s also an Explicit mode that lets you pick and choose the library pieces individually and reduce the footprint of ASP.NET AJAX script included if you are using the library. There’s also a new EnableCdn property that forces any script that has a new WebResource attribute CdnPath property set to a CDN supplied URL. If the script has this Attribute property set to a non-null/empty value and EnableCdn is enabled on the ScriptManager, that script will be served from the specified CdnPath. [assembly: WebResource(    "Westwind.Web.Resources.ww.jquery.js",    "application/x-javascript",    CdnPath =  "http://mysite.com/scripts/ww.jquery.min.js")] Cool, but a little too static for my taste since this value can’t be changed at runtime to point at a debug script as needed, for example. Assembly names for loading scripts from resources can now be simple names rather than fully qualified assembly names, which make it less verbose to reference scripts from assemblies loaded from your bin folder or the assembly reference area in web.config: <asp:ScriptManager runat="server" id="Id"          EnableCdn="true"         AjaxFrameworkMode="disabled">     <Scripts>         <asp:ScriptReference          Name="Westwind.Web.Resources.ww.jquery.js"         Assembly="Westwind.Web" />     </Scripts>        </asp:ScriptManager> The ScriptManager in 4.0 also supports script combining via the CompositeScript tag, which allows you to very easily combine scripts into a single script resource served via ASP.NET. Even nicer: You can specify the URL that the combined script is served with. Check out the following script manager markup that combines several static file scripts and a script resource into a single ASP.NET served resource from a static URL (allscripts.js): <asp:ScriptManager runat="server" id="Id"          EnableCdn="true"         AjaxFrameworkMode="disabled">     <CompositeScript          Path="~/scripts/allscripts.js">         <Scripts>             <asp:ScriptReference                    Path="~/scripts/jquery.js" />             <asp:ScriptReference                    Path="~/scripts/ww.jquery.js" />             <asp:ScriptReference            Name="Westwind.Web.Resources.editors.js"                 Assembly="Westwind.Web" />         </Scripts>     </CompositeScript> </asp:ScriptManager> When you render this into HTML, you’ll see a single script reference in the page: <script src="scripts/allscripts.debug.js"          type="text/javascript"></script> All you need to do to make this work is ensure that allscripts.js and allscripts.debug.js exist in the scripts folder of your application - they can be empty but the file has to be there. This is pretty cool, but you want to be real careful that you use unique URLs for each combination of scripts you combine or else browser and server caching will easily screw you up royally. The script manager also allows you to override native ASP.NET AJAX scripts now as any script references defined in the Scripts section of the ScriptManager trump internal references. So if you want custom behavior or you want to fix a possible bug in the core libraries that normally are loaded from resources, you can now do this simply by referencing the script resource name in the Name property and pointing at System.Web for the assembly. Not a common scenario, but when you need it, it can come in real handy. Still, there are a number of shortcomings in this control. For one, the ScriptManager and ClientScript APIs still have no common entry point so control developers are still faced with having to check and support both APIs to load scripts so that controls can work on pages that do or don’t have a ScriptManager on the page. The CdnUrl is static and compiled in, which is very restrictive. And finally, there’s still no control over where scripts get loaded on the page - ScriptManager still injects scripts into the middle of the HTML markup rather than in the header or optionally the footer. This, in turn, means there is little control over script loading order, which can be problematic for control developers. MetaDescription, MetaKeywords Page Properties There are also a number of additional Page properties that correspond to some of the other features discussed in this column: ClientIDMode, ClientTarget and ViewStateMode. Another minor but useful feature is that you can now directly access the MetaDescription and MetaKeywords properties on the Page object to set the corresponding meta tags programmatically. Updating these values programmatically previously required either <%= %> expressions in the page markup or dynamic insertion of literal controls into the page. You can now just set these properties programmatically on the Page object in any Control derived class on the page or the Page itself: Page.MetaKeywords = "ASP.NET,4.0,New Features"; Page.MetaDescription = "This article discusses the new features in ASP.NET 4.0"; Note, that there’s no corresponding ASP.NET tag for the HTML Meta element, so the only way to specify these values in markup and access them is via the @Page tag: <%@Page Language="C#"      CodeBehind="WebForm2.aspx.cs"     Inherits="Westwind.WebStore.WebForm2"      ClientIDMode="Static"                MetaDescription="Article that discusses what's                      new in ASP.NET 4.0"     MetaKeywords="ASP.NET,4.0,New Features" %> Nothing earth shattering but quite convenient. Visual Studio 2010 Enhancements for Web Development For Web development there are also a host of editor enhancements in Visual Studio 2010. Some of these are not Web specific but they are useful for Web developers in general. Text Editors Throughout Visual Studio 2010, the text editors have all been updated to a new core engine based on WPF which provides some interesting new features for various code editors including the nice ability to zoom in and out with Ctrl-MouseWheel to quickly change the size of text. There are many more API options to control the editor and although Visual Studio 2010 doesn’t yet use many of these features, we can look forward to enhancements in add-ins and future editor updates from the various language teams that take advantage of the visual richness that WPF provides to editing. On the negative side, I’ve noticed that occasionally the code editor and especially the HTML and JavaScript editors will lose the ability to use various navigation keys like arrows, back and delete keys, which requires closing and reopening the documents at times. This issue seems to be well documented so I suspect this will be addressed soon with a hotfix or within the first service pack. Overall though, the code editors work very well, especially given that they were re-written completely using WPF, which was one of my big worries when I first heard about the complete redesign of the editors. Multi-Targeting Visual Studio now targets all versions of the .NET framework from 2.0 forward. You can use Visual Studio 2010 to work on your ASP.NET 2, 3.0 and 3.5 applications which is a nice way to get your feet wet with the new development environment without having to make changes to existing applications. It’s nice to have one tool to work in for all the different versions. Multi-Monitor Support One cool feature of Visual Studio 2010 is the ability to drag windows out of the Visual Studio environment and out onto the desktop including onto another monitor easily. Since Web development often involves working with a host of designers at the same time - visual designer, HTML markup window, code behind and JavaScript editor - it’s really nice to be able to have a little more screen real estate to work on each of these editors. Microsoft made a welcome change in the environment. IntelliSense Snippets for HTML and JavaScript Editors The HTML and JavaScript editors now finally support IntelliSense scripts to create macro-based template expansions that have been in the core C# and Visual Basic code editors since Visual Studio 2005. Snippets allow you to create short XML-based template definitions that can act as static macros or real templates that can have replaceable values that can be embedded into the expanded text. The XML syntax for these snippets is straight forward and it’s pretty easy to create custom snippets manually. You can easily create snippets using XML and store them in your custom snippets folder (C:\Users\rstrahl\Documents\Visual Studio 2010\Code Snippets\Visual Web Developer\My HTML Snippets and My JScript Snippets), but it helps to use one of the third-party tools that exist to simplify the process for you. I use SnippetEditor, by Bill McCarthy, which makes short work of creating snippets interactively (http://snippeteditor.codeplex.com/). Note: You may have to manually add the Visual Studio 2010 User specific Snippet folders to this tool to see existing ones you’ve created. Code snippets are some of the biggest time savers and HTML editing more than anything deals with lots of repetitive tasks that lend themselves to text expansion. Visual Studio 2010 includes a slew of built-in snippets (that you can also customize!) and you can create your own very easily. If you haven’t done so already, I encourage you to spend a little time examining your coding patterns and find the repetitive code that you write and convert it into snippets. I’ve been using CodeRush for this for years, but now you can do much of the basic expansion natively for HTML and JavaScript snippets. jQuery Integration Is Now Native jQuery is a popular JavaScript library and recently Microsoft has recently stated that it will become the primary client-side scripting technology to drive higher level script functionality in various ASP.NET Web projects that Microsoft provides. In Visual Studio 2010, the default full project template includes jQuery as part of a new project including the support files that provide IntelliSense (-vsdoc files). IntelliSense support for jQuery is now also baked into Visual Studio 2010, so unlike Visual Studio 2008 which required a separate download, no further installs are required for a rich IntelliSense experience with jQuery. Summary ASP.NET 4.0 brings many useful improvements to the platform, but thankfully most of the changes are incremental changes that don’t compromise backwards compatibility and they allow developers to ease into the new features one feature at a time. None of the changes in ASP.NET 4.0 or Visual Studio 2010 are monumental or game changers. The bigger features are language and .NET Framework changes that are also optional. This ASP.NET and tools release feels more like fine tuning and getting some long-standing kinks worked out of the platform. It shows that the ASP.NET team is dedicated to paying attention to community feedback and responding with changes to the platform and development environment based on this feedback. If you haven’t gotten your feet wet with ASP.NET 4.0 and Visual Studio 2010, there’s no reason not to give it a shot now - the ASP.NET 4.0 platform is solid and Visual Studio 2010 works very well for a brand new release. Check it out. © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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  • C# serial port driver wrapper class code and concept quality

    - by Ruben Trancoso
    Hi folks, Would like to know from all you guys what you think about my Serial Wrapper class. Had be a while I've beem working with serial port but never shared the code what somekind make closed to my very own vision. Would like to know if it's a good/bad approach, if the interface is enough and what more you see on it. I know that Stackoverflow is for question but at the same time there's a lot of very good skilled people here and share code and opinion can also bennefit everybody, it's why I decided to post it anyway. thanks! using System.Text; using System.IO; using System.IO.Ports; using System; namespace Driver { class SerialSingleton { // The singleton instance reference private static SerialSingleton instance = null; // System's serial port interface private SerialPort serial; // Current com port identifier private string comPort = null; // Configuration parameters private int confBaudRate; private int confDataBits; private StopBits confStopBits; private Parity confParityControl; ASCIIEncoding encoding = new ASCIIEncoding(); // ================================================================================== // Constructors public static SerialSingleton getInstance() { if (instance == null) { instance = new SerialSingleton(); } return instance; } private SerialSingleton() { serial = new SerialPort(); } // =================================================================================== // Setup Methods public string ComPort { get { return comPort; } set { if (value == null) { throw new SerialException("Serial port name canot be null."); } if (nameIsComm(value)) { close(); comPort = value; } else { throw new SerialException("Serial Port '" + value + "' is not a valid com port."); } } } public void setSerial(string baudRate, int dataBits, StopBits stopBits, Parity parityControl) { if (baudRate == null) { throw new SerialException("Baud rate cannot be null"); } string[] baudRateRef = { "300", "600", "1200", "1800", "2400", "3600", "4800", "7200", "9600", "14400", "19200", "28800", "38400", "57600", "115200" }; int confBaudRate; if (findString(baudRateRef, baudRate) != -1) { confBaudRate = System.Convert.ToInt32(baudRate); } else { throw new SerialException("Baurate parameter invalid."); } int confDataBits; switch (dataBits) { case 5: confDataBits = 5; break; case 6: confDataBits = 6; break; case 7: confDataBits = 7; break; case 8: confDataBits = 8; break; default: throw new SerialException("Databits parameter invalid"); } if (stopBits == StopBits.None) { throw new SerialException("StopBits parameter cannot be NONE"); } this.confBaudRate = confBaudRate; this.confDataBits = confDataBits; this.confStopBits = stopBits; this.confParityControl = parityControl; } // ================================================================================== public string[] PortList { get { return SerialPort.GetPortNames(); } } public int PortCount { get { return SerialPort.GetPortNames().Length; } } // ================================================================================== // Open/Close Methods public void open() { open(comPort); } private void open(string comPort) { if (isOpen()) { throw new SerialException("Serial Port is Already open"); } else { if (comPort == null) { throw new SerialException("Serial Port not defined. Cannot open"); } bool found = false; if (nameIsComm(comPort)) { string portId; string[] portList = SerialPort.GetPortNames(); for (int i = 0; i < portList.Length; i++) { portId = (portList[i]); if (portId.Equals(comPort)) { found = true; break; } } } else { throw new SerialException("The com port identifier '" + comPort + "' is not a valid serial port identifier"); } if (!found) { throw new SerialException("Serial port '" + comPort + "' not found"); } serial.PortName = comPort; try { serial.Open(); } catch (UnauthorizedAccessException uaex) { throw new SerialException("Cannot open a serial port in use by another application", uaex); } try { serial.BaudRate = confBaudRate; serial.DataBits = confDataBits; serial.Parity = confParityControl; serial.StopBits = confStopBits; } catch (Exception e) { throw new SerialException("Serial port parameter invalid for '" + comPort + "'.\n" + e.Message, e); } } } public void close() { if (serial.IsOpen) { serial.Close(); } } // =================================================================================== // Auxiliary private Methods private int findString(string[] set, string search) { if (set != null) { for (int i = 0; i < set.Length; i++) { if (set[i].Equals(search)) { return i; } } } return -1; } private bool nameIsComm(string name) { int comNumber; int.TryParse(name.Substring(3), out comNumber); if (name.Substring(0, 3).Equals("COM")) { if (comNumber > -1 && comNumber < 256) { return true; } } return false; } // ================================================================================= // Device state Methods public bool isOpen() { return serial.IsOpen; } public bool hasData() { int amount = serial.BytesToRead; if (amount > 0) { return true; } else { return false; } } // ================================================================================== // Input Methods public char getChar() { int data = serial.ReadByte(); return (char)data; } public int getBytes(ref byte[] b) { int size = b.Length; char c; int counter = 0; for (counter = 0; counter < size; counter++) { if (tryGetChar(out c)) { b[counter] = (byte)c; } else { break; } } return counter; } public string getStringUntil(char x) { char c; string response = ""; while (tryGetChar(out c)) { response = response + c; if (c == x) { break; } } return response; } public bool tryGetChar(out char c) { c = (char)0x00; byte[] b = new byte[1]; long to = 10; long ft = System.Environment.TickCount + to; while (System.Environment.TickCount < ft) { if (hasData()) { int data = serial.ReadByte(); c = (char)data; return true; } } return false; } // ================================================================================ // Output Methods public void sendString(string data) { byte[] bytes = encoding.GetBytes(data); serial.Write(bytes, 0, bytes.Length); } public void sendChar(char c) { char[] data = new char[1]; data[0] = c; serial.Write(data, 0, 1); } public void sendBytes(byte[] data) { serial.Write(data, 0, data.Length); } public void clearBuffer() { if (serial.IsOpen) { serial.DiscardInBuffer(); serial.DiscardOutBuffer(); } } } }

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  • Snort's problems in generating alert from Darpa 1998 intrusion detection dataset.

    - by manofseven2
    Hi. I’m working on DARPA 1998 intrusion detection dataset. When I run snort on this dataset (outside.tcpdump file), snort don’t generate complete list of alerts. It means snort start from last few hours of tcpdump file and generate alerts about this section of file and all of packets in first hours are ignored. Another problem in generatin alert is in time stamp of generated alerts. This means when I run snort on a specific day of dataset, snort insert incorrect time stamp for that alert. The configuration and command line statement and other information about my research are: Snort version: 2.8.6 Operating system: windows XP Rule version: snortrules-snapshot-2860_s.tar.gz -———————————————————————— Command line: snort_2.8.6 c D:\programs\Snort_2.8.6\snort\etc\snort.conf -r d:\users\amir\docs\darpa\training_data\week_3\monday\outside.tcpdump -l D:\users\amir\current-task\research\thesis\snort\890230 -————————————————————————— Snort.config Hi. I'm working on DARPA 1998 intrusion detection dataset. When I run snort on this dataset (outside.tcpdump file), snort don't generate complete list of alerts. It means snort start from last few hours of tcpdump file and generate alerts about this section of file and all of packets in first hours are ignored. Another problem in generatin alert is in time stamp of generated alerts. This means when I run snort on a specific day of dataset, snort insert incorrect time stamp for that alert. The configuration and command line statement and other information about my research are: Snort version: 2.8.6 Operating system: windows XP Rule version: snortrules-snapshot-2860_s.tar.gz Command line: snort_2.8.6 -c D:\programs\Snort_2.8.6\snort\etc\snort.conf -r d:\users\amir\docs\darpa\training_data\week_3\monday\outside.tcpdump -l D:\users\amir\current-task\research\thesis\snort\890230 Snort.config # Setup the network addresses you are protecting var HOME_NET any # Set up the external network addresses. Leave as "any" in most situations var EXTERNAL_NET any # List of DNS servers on your network var DNS_SERVERS $HOME_NET # List of SMTP servers on your network var SMTP_SERVERS $HOME_NET # List of web servers on your network var HTTP_SERVERS $HOME_NET # List of sql servers on your network var SQL_SERVERS $HOME_NET # List of telnet servers on your network var TELNET_SERVERS $HOME_NET # List of ssh servers on your network var SSH_SERVERS $HOME_NET # List of ports you run web servers on portvar HTTP_PORTS [80,1220,2301,3128,7777,7779,8000,8008,8028,8080,8180,8888,9999] # List of ports you want to look for SHELLCODE on. portvar SHELLCODE_PORTS !80 # List of ports you might see oracle attacks on portvar ORACLE_PORTS 1024: # List of ports you want to look for SSH connections on: portvar SSH_PORTS 22 # other variables, these should not be modified var AIM_SERVERS [64.12.24.0/23,64.12.28.0/23,64.12.161.0/24,64.12.163.0/24,64.12.200.0/24,205.188.3.0/24,205.188.5.0/24,205.188.7.0/24,205.188.9.0/24,205.188.153.0/24,205.188.179.0/24,205.188.248.0/24] var RULE_PATH ../rules var SO_RULE_PATH ../so_rules var PREPROC_RULE_PATH ../preproc_rules # Stop generic decode events: config disable_decode_alerts # Stop Alerts on experimental TCP options config disable_tcpopt_experimental_alerts # Stop Alerts on obsolete TCP options config disable_tcpopt_obsolete_alerts # Stop Alerts on T/TCP alerts config disable_tcpopt_ttcp_alerts # Stop Alerts on all other TCPOption type events: config disable_tcpopt_alerts # Stop Alerts on invalid ip options config disable_ipopt_alerts # Alert if value in length field (IP, TCP, UDP) is greater th elength of the packet # config enable_decode_oversized_alerts # Same as above, but drop packet if in Inline mode (requires enable_decode_oversized_alerts) # config enable_decode_oversized_drops # Configure IP / TCP checksum mode config checksum_mode: all config pcre_match_limit: 1500 config pcre_match_limit_recursion: 1500 # Configure the detection engine See the Snort Manual, Configuring Snort - Includes - Config config detection: search-method ac-split search-optimize max-pattern-len 20 # Configure the event queue. For more information, see README.event_queue config event_queue: max_queue 8 log 3 order_events content_length dynamicpreprocessor directory D:\programs\Snort_2.8.6\snort\lib\snort_dynamicpreprocessor dynamicengine D:\programs\Snort_2.8.6\snort\lib\snort_dynamicengine\sf_engine.dll # path to dynamic rules libraries #dynamicdetection directory /usr/local/lib/snort_dynamicrules preprocessor frag3_global: max_frags 65536 preprocessor frag3_engine: policy windows detect_anomalies overlap_limit 10 min_fragment_length 100 timeout 180 preprocessor stream5_global: max_tcp 8192, track_tcp yes, track_udp yes, track_icmp no preprocessor stream5_tcp: policy windows, detect_anomalies, require_3whs 180, \ overlap_limit 10, small_segments 3 bytes 150, timeout 180, \ ports client 21 22 23 25 42 53 79 109 110 111 113 119 135 136 137 139 143 \ 161 445 513 514 587 593 691 1433 1521 2100 3306 6665 6666 6667 6668 6669 \ 7000 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, \ ports both 80 443 465 563 636 989 992 993 994 995 1220 2301 3128 6907 7702 7777 7779 7801 7900 7901 7902 7903 7904 7905 \ 7906 7908 7909 7910 7911 7912 7913 7914 7915 7916 7917 7918 7919 7920 8000 8008 8028 8080 8180 8888 9999 preprocessor stream5_udp: timeout 180 preprocessor http_inspect: global iis_unicode_map unicode.map 1252 compress_depth 20480 decompress_depth 20480 preprocessor http_inspect_server: server default \ chunk_length 500000 \ server_flow_depth 0 \ client_flow_depth 0 \ post_depth 65495 \ oversize_dir_length 500 \ max_header_length 750 \ max_headers 100 \ ports { 80 1220 2301 3128 7777 7779 8000 8008 8028 8080 8180 8888 9999 } \ non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \ enable_cookie \ extended_response_inspection \ inspect_gzip \ apache_whitespace no \ ascii no \ bare_byte no \ directory no \ double_decode no \ iis_backslash no \ iis_delimiter no \ iis_unicode no \ multi_slash no \ non_strict \ u_encode yes \ webroot no preprocessor rpc_decode: 111 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779 no_alert_multiple_requests no_alert_large_fragments no_alert_incomplete preprocessor bo preprocessor ftp_telnet: global inspection_type stateful encrypted_traffic no preprocessor ftp_telnet_protocol: telnet \ ayt_attack_thresh 20 \ normalize ports { 23 } \ detect_anomalies preprocessor ftp_telnet_protocol: ftp server default \ def_max_param_len 100 \ ports { 21 2100 3535 } \ telnet_cmds yes \ ignore_telnet_erase_cmds yes \ ftp_cmds { ABOR ACCT ADAT ALLO APPE AUTH CCC CDUP } \ ftp_cmds { CEL CLNT CMD CONF CWD DELE ENC EPRT } \ ftp_cmds { EPSV ESTA ESTP FEAT HELP LANG LIST LPRT } \ ftp_cmds { LPSV MACB MAIL MDTM MIC MKD MLSD MLST } \ ftp_cmds { MODE NLST NOOP OPTS PASS PASV PBSZ PORT } \ ftp_cmds { PROT PWD QUIT REIN REST RETR RMD RNFR } \ ftp_cmds { RNTO SDUP SITE SIZE SMNT STAT STOR STOU } \ ftp_cmds { STRU SYST TEST TYPE USER XCUP XCRC XCWD } \ ftp_cmds { XMAS XMD5 XMKD XPWD XRCP XRMD XRSQ XSEM } \ ftp_cmds { XSEN XSHA1 XSHA256 } \ alt_max_param_len 0 { ABOR CCC CDUP ESTA FEAT LPSV NOOP PASV PWD QUIT REIN STOU SYST XCUP XPWD } \ alt_max_param_len 200 { ALLO APPE CMD HELP NLST RETR RNFR STOR STOU XMKD } \ alt_max_param_len 256 { CWD RNTO } \ alt_max_param_len 400 { PORT } \ alt_max_param_len 512 { SIZE } \ chk_str_fmt { ACCT ADAT ALLO APPE AUTH CEL CLNT CMD } \ chk_str_fmt { CONF CWD DELE ENC EPRT EPSV ESTP HELP } \ chk_str_fmt { LANG LIST LPRT MACB MAIL MDTM MIC MKD } \ chk_str_fmt { MLSD MLST MODE NLST OPTS PASS PBSZ PORT } \ chk_str_fmt { PROT REST RETR RMD RNFR RNTO SDUP SITE } \ chk_str_fmt { SIZE SMNT STAT STOR STRU TEST TYPE USER } \ chk_str_fmt { XCRC XCWD XMAS XMD5 XMKD XRCP XRMD XRSQ } \ chk_str_fmt { XSEM XSEN XSHA1 XSHA256 } \ cmd_validity ALLO \ cmd_validity EPSV \ cmd_validity MACB \ cmd_validity MDTM \ cmd_validity MODE \ cmd_validity PORT \ cmd_validity PROT \ cmd_validity STRU \ cmd_validity TYPE preprocessor ftp_telnet_protocol: ftp client default \ max_resp_len 256 \ bounce yes \ ignore_telnet_erase_cmds yes \ telnet_cmds yes preprocessor smtp: ports { 25 465 587 691 } \ inspection_type stateful \ normalize cmds \ normalize_cmds { MAIL RCPT HELP HELO ETRN EHLO EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET SEND SAML SOML AUTH TURN DATA QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \ max_command_line_len 512 \ max_header_line_len 1000 \ max_response_line_len 512 \ alt_max_command_line_len 260 { MAIL } \ alt_max_command_line_len 300 { RCPT } \ alt_max_command_line_len 500 { HELP HELO ETRN EHLO } \ alt_max_command_line_len 255 { EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET } \ alt_max_command_line_len 246 { SEND SAML SOML AUTH TURN ETRN DATA RSET QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \ valid_cmds { MAIL RCPT HELP HELO ETRN EHLO EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET SEND SAML SOML AUTH TURN DATA QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \ xlink2state { enabled } preprocessor ssh: server_ports { 22 } \ autodetect \ max_client_bytes 19600 \ max_encrypted_packets 20 \ max_server_version_len 100 \ enable_respoverflow enable_ssh1crc32 \ enable_srvoverflow enable_protomismatch preprocessor dcerpc2: memcap 102400, events [co ] preprocessor dcerpc2_server: default, policy WinXP, \ detect [smb [139,445], tcp 135, udp 135, rpc-over-http-server 593], \ autodetect [tcp 1025:, udp 1025:, rpc-over-http-server 1025:], \ smb_max_chain 3 preprocessor dns: ports { 53 } enable_rdata_overflow preprocessor ssl: ports { 443 465 563 636 989 992 993 994 995 7801 7702 7900 7901 7902 7903 7904 7905 7906 6907 7908 7909 7910 7911 7912 7913 7914 7915 7916 7917 7918 7919 7920 }, trustservers, noinspect_encrypted # SDF sensitive data preprocessor. For more information see README.sensitive_data preprocessor sensitive_data: alert_threshold 25 output alert_full: alert.log output database: log, mysql, user=root password=123456 dbname=snort host=localhost include classification.config include reference.config include $RULE_PATH/local.rules include $RULE_PATH/attack-responses.rules include $RULE_PATH/backdoor.rules include $RULE_PATH/bad-traffic.rules include $RULE_PATH/chat.rules include $RULE_PATH/content-replace.rules include $RULE_PATH/ddos.rules include $RULE_PATH/dns.rules include $RULE_PATH/dos.rules include $RULE_PATH/exploit.rules include $RULE_PATH/finger.rules include $RULE_PATH/ftp.rules include $RULE_PATH/icmp.rules include $RULE_PATH/icmp-info.rules include $RULE_PATH/imap.rules include $RULE_PATH/info.rules include $RULE_PATH/misc.rules include $RULE_PATH/multimedia.rules include $RULE_PATH/mysql.rules include $RULE_PATH/netbios.rules include $RULE_PATH/nntp.rules include $RULE_PATH/oracle.rules include $RULE_PATH/other-ids.rules include $RULE_PATH/p2p.rules include $RULE_PATH/policy.rules include $RULE_PATH/pop2.rules include $RULE_PATH/pop3.rules include $RULE_PATH/rpc.rules include $RULE_PATH/rservices.rules include $RULE_PATH/scada.rules include $RULE_PATH/scan.rules include $RULE_PATH/shellcode.rules include $RULE_PATH/smtp.rules include $RULE_PATH/snmp.rules include $RULE_PATH/specific-threats.rules include $RULE_PATH/spyware-put.rules include $RULE_PATH/sql.rules include $RULE_PATH/telnet.rules include $RULE_PATH/tftp.rules include $RULE_PATH/virus.rules include $RULE_PATH/voip.rules include $RULE_PATH/web-activex.rules include $RULE_PATH/web-attacks.rules include $RULE_PATH/web-cgi.rules include $RULE_PATH/web-client.rules include $RULE_PATH/web-coldfusion.rules include $RULE_PATH/web-frontpage.rules include $RULE_PATH/web-iis.rules include $RULE_PATH/web-misc.rules include $RULE_PATH/web-php.rules include $RULE_PATH/x11.rules include threshold.conf -————————————————————————————- Can anyone help me to solve this problem? Thanks.

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  • Implementing an async "read all currently available data from stream" operation

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a console's standard output Stream. Console output streams are of type FileStream; the implementation can cast to that, if needed. There is also an associated StreamReader already present to leverage. There is only one thing I need to implement in this class to achieve my desired functionality: an async "read all the data available this moment" operation. Reading to the end of the stream is not viable because the stream will not end unless the process closes the console output handle, and it will not do that because it is interactive and expecting input before continuing. I will be using that hypothetical async operation to implement event-based notification, which will be more convenient for my callers. The public interface of the class is this: public class ConsoleAutomator { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Remember that the goal here is to read all of the chunk and call event subscribers exactly once for each chunk. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream. private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer (in which case we know that there was no more data to be read during the last read operation), all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Never more than one event for each time data is available to be read Is almost agnostic to the buffer size The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this. Update: I definitely did not communicate the scenario well in my initial writeup. I have since revised the writeup quite a bit, but to be extra sure: The question is about how to implement an async "read all the data available this moment" operation. My apologies to the people who took the time to read and answer without me making my intent clear enough.

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  • Delphi - Proper way to page though data.

    - by Brad
    I have a string list (TStrings) that has a couple thousand items in it. I need to process them in groups of 100. I basically want to know what the best way to do the loop is in Delphi. I'm hitting a brick wall when I'm trying to figure it out. Thanks unit Unit2; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm2 = class(TForm) Memo1: TMemo; Memo2: TMemo; Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form2: TForm2; implementation Uses math; {$R *.dfm} procedure TForm2.Button1Click(Sender: TObject); var I:Integer; pages:Integer; str:string; begin pages:= ceil(memo1.Lines.Count/100) ; memo2.Lines.add('Total Pages: '+inttostr(pages)); memo2.Lines.add('Total Items: '+inttostr(memo1.Lines.Count)); // Should just do in batches of 100 VS entire list for I := 0 to memo1.lines.Count - 1 do begin if str '' then str:= str+#10+ memo1.Lines.Strings[i] else str:= memo1.Lines.Strings[i]; end; //I need to stop here every 100 items, then process the items. memo2.Lines.Add(str); end; end. Example form object Form2: TForm2 Left = 0 Top = 0 Caption = 'Form2' ClientHeight = 245 ClientWidth = 527 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'Tahoma' Font.Style = [] OldCreateOrder = False PixelsPerInch = 96 TextHeight = 13 object Memo1: TMemo Left = 16 Top = 8 Width = 209 Height = 175 Lines.Strings = ( '4xlt columbia thunder storm jacket' '5 things about thunder storms' 'a thunder storm with a lot of thunder ' 'and lighting sccreensaver' 'a thunder storm with a lot of thunder ' 'and lighting screensaver with no nag ' 'screens' 'all about thunder storms' 'all about thunderstorms for kids' 'amazing tornado videos and ' 'thunderstorm videos' 'are thunder storms louder in ohio?' 'bad thunder storms' 'bathing in thunder storm' 'best thunderstorm pictures' 'cartoon thunder storms' 'celtic thunder storm' 'central valley thunder storm' 'chicago thunderstorm pictures' 'cool thunderstorm pictures' 'current thunderstorm warnings' 'does thunder storms in december mean ' 'snow will be coming' 'facts about thunderstorms for kids' 'facts on thunderstorms for kids' 'fedex thunderstorm video' 'florida thunderstorms facts' 'free relaxing thunderstorm music' 'free soothing thunderstorm sounds ' 'online' 'free thunderstorm mp3' 'free thunderstorm mp3 download' 'free thunderstorm mp3 downloads' 'free thunderstorm mp3s' 'free thunderstorm music' 'free thunderstorm pictures' 'free thunderstorm sound effects' 'free thunderstorm sounds' 'free thunderstorm sounds cd' 'free thunderstorm sounds mp3' 'free thunderstorm sounds online' 'free thunderstorm soundscape' 'free thunderstorm video' 'free thunderstorm video download' 'free thunderstorm videos' 'god of storm and thunder' 'horses storm thunder rain' 'how do thunder storms form' 'how far away is a thunder storm' 'how long do thunder storms last' 'ice cube in a thunder storm' 'indoor thunderstorm safety tips' 'information about thunderstorms for kids' 'interesting thunderstorm facts' 'is it dangerous to shower during thunder ' 'storm' 'is there frequently thunder during snow ' 'storms' 'isolated thunderstorms' 'it'#39's just a thunder storm baby there is ' 'nothing you should fear lyrics' 'lightning & thunder storm safety' 'lightning and thunderstorm facts' 'lightning and thunderstorms facts' 'lightning and thunderstorms for kids' 'listen to thunderstorm sounds online' 'mississauga thunder storm' 'nature sounds free mp3 thunder storm' 'only about thunderstorms facts' 'original storm deep thunderstick' 'phone use during thunder storms' 'pictures of thunderstorms' 'pocono thunder storm' 'posters of thunder storms' 'power rangers ninja storm' 'power rangers thunder storm' 'power rangers thunder storm cast' 'power rangers thunder storm games' 'power rangers thunder storm morphers' 'power rangers thunder storm part 1' 'power rangers thunder storm part 2' 'power rangers thunderstorm' 'power rangers thunderstorm cannon' 'power rangers thunderstorm deluxe ' 'megazord' 'power rangers thunderstorm games' 'power rangers thunderstorm megazord' 'power rangers thunderstorm part 2' 'power rangers thunderstorm pictures' 'power rnager ninja storm thunder staff' 'powerful thunder and lightning storms' 'precambrian thunder storms' 'rain thunderstorm mp3' 'rain thunderstorm pictures' 'relaxing thunderstorm music' 'reminds me of ohio river thunder lighten ' 'storms' 'sacramento thunder storm' 'safety tips for when your caught in a ' 'thunder storm' 'scattered thunderstorms' 'schemer puts his head in the thunder ' 'storm' 'sedative thunder storm' 'server thunder storms' 'severe supercell thunderstorm pictures' 'severe thunder storm pictures' 'severe thunder storms' 'severe thunderstorm facts' 'severe thunderstorm pictures' 'severe thunderstorm pictures hail' 'severe thunderstorm pictures in alberta' 'severe thunderstorm pictures tornado' 'severe thunderstorm safety' 'severe thunderstorm safety tips' 'severe thunderstorm videos' 'severe thunderstorm warning' 'severe thunderstorm warning los ' 'angeles' 'severe thunderstorm warning signs' 'severe thunderstorm warnings' 'severe thunderstorms' 'severe thunderstorms facts' 'shakespeare use thunder storm for ' 'cosmic disorder julius caesar' 'soothing thunderstorm sounds online' 'sound effects of severe thunder storm' 'sound of rain storm finger snapping ' 'thunder chorus' 'split thunder storm' 'storm 3d thunder power' 'storm dark thunder' 'storm dark thunder bowling ball' 'storm dark thunder bowling ball sale' 'storm dark thunder for sale' 'storm dark thunder pearl' 'storm dark thunder pearl bowling ball' 'storm dark thunder review' 'storm dark thunder shirt' 'storm dark thunderball' 'storm deep thunder' 'storm deep thunder 11' 'storm deep thunder 15' 'storm deep thunder 15 lure' 'storm deep thunder 2' 'storm deep thunder lures' 'storm deep thunderstick' 'storm deep thunderstick crankbaits' 'storm deep thunderstick dts09' 'storm deep thunderstick jr' 'storm deep thunderstick lures' 'storm deep thundersticks' 'storm rolling thunder 3 ball roller' 'storm rolling thunder bowling bag' 'storm rolling thunder three ball bowling ' 'bag' 'storm shallow thunder' 'storm shallow thunder 15' 'storm thunder claw' 'storm thunder craw' 'storm watches thunder' 'storms with constant lightning and ' 'thunder non-stop' 'supercell thunder storms' 'supercell thunderstorm pictures' 'supercell thunderstorms' 'swimming pools thunder storms' 'tampa + lightning strikes + thunder ' 'storms' 'texas thunderstorm pictures' 'texas thunderstorm warnings' 'thunder and lightning storm' 'thunder and lighting storms' 'thunder and lightning storms' 'thunder bay snow storm video' 'thunder storm' 'thunder storm and windmill' 'thunder storm cd' 'thunder storm cloud' 'thunder storm clouds' 'thunder storm dog peppermint oil' 'thunder storm in winter' 'thunder storm in winter and weather ' 'prediction' 'thunder storm lx-3 & road blaster psx ' 'download' 'thunder storm occurances' 'thunder storm photos' 'thunder storm poems' 'thunder storm safety' 'thunder storm sign' 'thunder storm sounds' 'thunder storms' 'thunder storms and deaths' 'thunder storms and ilghting' 'thunder storms and lighting' 'thunder storms cd' 'thunder storms in the arctic arctic ' 'weather' 'thunder storms in winter' 'thunder storms on you tub' 'thunder storms pics' 'thunder storms with rain' 'thunderstorm' 'thunderstorm backgrounds' 'thunderstorm capital' 'thunderstorm capital 2008 dorfman' 'thunderstorm capital in boston' 'thunderstorm capital llc' 'thunderstorm capital of canada' 'thunderstorm capital of the us' 'thunderstorm capital of the world' 'thunderstorm facts' 'thunderstorm facts for kids' 'thunderstorm facts hail' 'thunderstorm facts tornadoes' 'thunderstorm mp3' 'thunderstorm mp3 download' 'thunderstorm mp3 download free' 'thunderstorm mp3 downloads' 'thunderstorm mp3 downloads free' 'thunderstorm mp3 files' 'thunderstorm mp3 free' 'thunderstorm mp3 free download' 'thunderstorm mp3 free downloads' 'thunderstorm mp3 torrent' 'thunderstorm mp3s' 'thunderstorm music' 'thunderstorm music cd' 'thunderstorm music downloads' 'thunderstorm music free' 'thunderstorm music playlists' 'thunderstorm music rain' 'thunderstorm pics' 'thunderstorm pictures' 'thunderstorm pictures for kids' 'thunderstorm safety' 'thunderstorm safety for kids' 'thunderstorm safety precautions' 'thunderstorm safety procedures' 'thunderstorm safety rules' 'thunderstorm safety tips' 'thunderstorm safety tips for kids' 'thunderstorm safety tips shelter' 'thunderstorm safety tips trees' 'thunderstorm sound effects' 'thunderstorm sound effects cd' 'thunderstorm sound effects download' 'thunderstorm sound effects free' 'thunderstorm sound effects free ' 'download' 'thunderstorm sound effects free music ' 'feature audio' 'thunderstorm sound effects mp3' 'thunderstorm sound effects rain' 'thunderstorm sounds' 'thunderstorm sounds cd' 'thunderstorm sounds download' 'thunderstorm sounds for sleep' 'thunderstorm sounds for sleeping' 'thunderstorm sounds free' 'thunderstorm sounds free download' 'thunderstorm sounds free downloads' 'thunderstorm sounds mp3' 'thunderstorm sounds mp3 download' 'thunderstorm sounds mp3 free' 'thunderstorm sounds online' 'thunderstorm sounds online for free' 'thunderstorm sounds online free' 'thunderstorm sounds sleep' 'thunderstorm sounds streaming' 'thunderstorm sounds torrent' 'thunderstorm soundscape' 'thunderstorm soundscapes' 'thunderstorm video' 'thunderstorm video clips' 'thunderstorm video download' 'thunderstorm video downloads' 'thunderstorm videos' 'thunderstorm videos for kids' 'thunderstorm videos lightning' 'thunderstorm videos online' 'thunderstorm wallpaper' 'thunderstorm warning' 'thunderstorm warning brisbane' 'thunderstorm warning definition' 'thunderstorm warning los angeles' 'thunderstorm warning san diego' 'thunderstorm warning san mateo county' 'thunderstorm warning santa barbara' 'thunderstorm warning santa clara' 'thunderstorm warning santa clara ' 'county' 'thunderstorm warning signal' 'thunderstorm warning signs' 'thunderstorm warning vs watch' 'thunderstorm warnings' 'thunderstorm warnings and watches' 'thunderstorm warnings for nj' 'thunderstorm warnings qld' 'thunderstorms' 'thunderstorms facts' 'thunderstorms facts for kids' 'thunderstorms for kids' 'tornados and thunder storms animated' 'understanding thunderstorms for kids' 'watch thunderstorm videos' 'weather underground forecast ' 'thunderstorms' 'what causes thunder storms' 'what is a thunder storm' 'where d thunder storms occur') TabOrder = 0 end object Memo2: TMemo Left = 240 Top = 8 Width = 265 Height = 129 Lines.Strings = ( 'Memo2') TabOrder = 1 end object Button1: TButton Left = 384 Top = 184 Width = 75 Height = 25 Caption = 'Button1' TabOrder = 2 OnClick = Button1Click end end

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  • Simplemodal: four times on a page leads to extra "next" or "previous" button

    - by DDF
    We are experiencing a problem with each instance of the call to the simplemodal div class .basic-modal-content adding an extra next or previous button in the modal windows. We are using simplemodal in four places on a page using a common JS in the container (provided below) and a common CSS format for the modal windows. In one area we are using six "statements" in a window with a next and previous button. I would include a picture of the modal window but it's being disallowed by the system as I'm a first time poster to this forum. In the other three areas we are using three "biographies" in a similar window with the ability to see each of the three bios from each of modal windows. We are using a common Simplemodal JS script in the page which has the following code: <script> $(function() { $('a').each(function() { $(this).click(function() { $('#modal_' + this.id).modal({ overlayClose:true }); }); }); var num_divs = $('div.basic-modal-content').length; $('div.basic-modal-content').each(function(i) { /* if there is a previous div add a link to it */ if (i > 0) { /* get the ID for previous div */ var prev_id = $(this).prev('.basic-modal-content').attr('id'); /* add the link with click event */ $('<a href="#" class="simplemodal-container-prev"></a>') .click(function() { $.modal.close(); $('#' + prev_id).modal({overlayClose:true}); }) .appendTo($(this)); } /* if there is a next div add a link to it */ if (i < num_divs - 1) { /* get the ID for next div */ var next_id = $(this).next('.basic-modal-content').attr('id'); /* add the link with click event */ $('<a href="#" class="simplemodal-container-next"></a>') .click(function() { $.modal.close(); $('#' + next_id).modal({overlayClose:true}); }) .appendTo($(this)); } }); }); </script> and some CSS to create an image for each window that shows the progress bar through the ul/li list. The code to produce the above looks like this: <h1>Our HEADLINE</h1> <div id='basic-modal'> <ul> <li><a href='#' id='one'>TEXT 1</a></li> <li><a href='#' id='two'>TEXT 2</a></li> <li><a href='#' id='three'>TEXT 3</a></li> <li><a href='#' id='four'>TEXT 4</a></li> <li><a href='#' id='five'>TEXT 5</a></li> <li><a href='#' id='six'>TEXT 6</a></li> </ul> </div> <div class="basic-modal-content" id="modal_one"> <img src="link to modal_one.png" alt="progress bar"/> <h3>headline text</h3> <p>body text</p> </div> <div class="basic-modal-content" id="modal_two"> <img src="link to modal_two.png" alt="progress bar"/> <h3>headline text</h3> <p>body text</p> </div> <div> ... other divs 3 4 and 5 </div> <div class="basic-modal-content" id="modal_six"> <img src="link to modal_six.png" alt="progress bar"/> <h3>headline text</h3> <p>body text</p> </div> </div> The ul/li structure works on the main page for the links. The modal windows allow one to browse through all of the six TEXTs. There is a common CSS style to the windows and a custom image in each of the modal windows derived from the "#modal_[number] img" CSS in the form of a progress bar. It should be noted that the first modal window in the first set of ul/li (the six) do not exhibit the extra previous button. Here is the relevant code from one of the three biographic links. You will note that the biographic links each have to have all three in this current configuration. <h4>Our HEADLINE</h4> <div class="bottom-widget-text"> <img src="picture" alt="not relevant to the simplemodal problem"/> <p>Read about person NUMBER 1 by clicking on the following link: <a href='#' id='seven' >Expand</a> </p> </div> <div class="basic-modal-content" id="modal_seven"> <img src="link to modal_seven.png" alt="portrait 1"/> <h3>headline text</h3> <p>BIOGRAPHY</p> </div> <div class="basic-modal-content" id="modal_eight"> <img src="link to modal_eight.png" alt="portrait 2"/> <h3>headline text</h3> <p>BIOGRAPHY</p> </div> <div class="basic-modal-content" id="modal_nine"> <img src="link to modal_nine.png" alt="portrait 3"/> <h3>headline text</h3> <p>BIOGRAPHY</p> </div> </div> Similarly the "biographies" open up from a different area of the page. The modal windows allow one to browse through all three of the BIOs. The bios use the SAME CSS style windows and a custom image in each of the modal windows derived from the "#modal_[number] img" CSS in the form of a portrait. Everything is working well except one thing: the first six windows have an extra next button that leads to an image of the close widow button only. Similarly, the BIOs pages have extra previous button that leads to the same "close button only" shown above. We want to maintain the same base CSS for the modal windows for this page. We want to keep the JS simple. The only behavior that is bad is the extra previous and next bottons that appear to be spurious. So is this a fix to the JS? Or do I have the instances of the modal windows too entangled? Perhaps there is a better method for having multiple instances of a simplemodal window on the same page? Or is the problem the "#" variable being common to each of the uses of the JS? Thanks in advance. DDF

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  • TSQL Conditionally Select Specific Value

    - by Dzejms
    This is a follow-up to #1644748 where I successfully answered my own question, but Quassnoi helped me to realize that it was the wrong question. He gave me a solution that worked for my sample data, but I couldn't plug it back into the parent stored procedure because I fail at SQL 2005 syntax. So here is an attempt to paint the broader picture and ask what I actually need. This is part of a stored procedure that returns a list of items in a bug tracking application I've inherited. There are are over 100 fields and 26 joins so I'm pulling out only the mostly relevant bits. SELECT tickets.ticketid, tickets.tickettype, tickets_tickettype_lu.tickettypedesc, tickets.stage, tickets.position, tickets.sponsor, tickets.dev, tickets.qa, DATEDIFF(DAY, ticket_history_assignment.savedate, GETDATE()) as 'daysinqueue' FROM dbo.tickets WITH (NOLOCK) LEFT OUTER JOIN dbo.tickets_tickettype_lu WITH (NOLOCK) ON tickets.tickettype = tickets_tickettype_lu.tickettypeid LEFT OUTER JOIN dbo.tickets_history_assignment WITH (NOLOCK) ON tickets_history_assignment.ticketid = tickets.ticketid AND tickets_history_assignment.historyid = ( SELECT MAX(historyid) FROM dbo.tickets_history_assignment WITH (NOLOCK) WHERE tickets_history_assignment.ticketid = tickets.ticketid GROUP BY tickets_history_assignment.ticketid ) WHERE tickets.sponsor = @sponsor The area of interest is the daysinqueue subquery mess. The tickets_history_assignment table looks roughly as follows declare @tickets_history_assignment table ( historyid int, ticketid int, sponsor int, dev int, qa int, savedate datetime ) insert into @tickets_history_assignment values (1521402, 92774,20,14, 20, '2009-10-27 09:17:59.527') insert into @tickets_history_assignment values (1521399, 92774,20,14, 42, '2009-08-31 12:07:52.917') insert into @tickets_history_assignment values (1521311, 92774,100,14, 42, '2008-12-08 16:15:49.887') insert into @tickets_history_assignment values (1521336, 92774,100,14, 42, '2009-01-16 14:27:43.577') Whenever a ticket is saved, the current values for sponsor, dev and qa are stored in the tickets_history_assignment table with the ticketid and a timestamp. So it is possible for someone to change the value for qa, but leave sponsor alone. What I want to know, based on all of these conditions, is the historyid of the record in the tickets_history_assignment table where the sponsor value was last changed so that I can calculate the value for daysinqueue. If a record is inserted into the history table, and only the qa value has changed, I don't want that record. So simply relying on MAX(historyid) won't work for me. Quassnoi came up with the following which seemed to work with my sample data, but I can't plug it into the larger query, SQL Manager bitches about the WITH statement. ;WITH rows AS ( SELECT *, ROW_NUMBER() OVER (PARTITION BY ticketid ORDER BY savedate DESC) AS rn FROM @Table ) SELECT rl.sponsor, ro.savedate FROM rows rl CROSS APPLY ( SELECT TOP 1 rc.savedate FROM rows rc JOIN rows rn ON rn.ticketid = rc.ticketid AND rn.rn = rc.rn + 1 AND rn.sponsor <> rc.sponsor WHERE rc.ticketid = rl.ticketid ORDER BY rc.rn ) ro WHERE rl.rn = 1 I played with it yesterday afternoon and got nowhere because I don't fundamentally understand what is going on here and how it should fit into the larger context. So, any takers? UPDATE Ok, here's the whole thing. I've been switching some of the table and column names in an attempt to simplify things so here's the full unedited mess. snip - old bad code Here are the errors: Msg 102, Level 15, State 1, Procedure usp_GetProjectRecordsByAssignment, Line 159 Incorrect syntax near ';'. Msg 102, Level 15, State 1, Procedure usp_GetProjectRecordsByAssignment, Line 179 Incorrect syntax near ')'. Line numbers are of course not correct but refer to ;WITH rows AS And the ')' char after the WHERE rl.rn = 1 ) Respectively Is there a tag for extra super long question? UPDATE #2 Here is the finished query for anyone who may need this: CREATE PROCEDURE [dbo].[usp_GetProjectRecordsByAssignment] ( @assigned numeric(18,0), @assignedtype numeric(18,0) ) AS SET NOCOUNT ON WITH rows AS ( SELECT *, ROW_NUMBER() OVER (PARTITION BY recordid ORDER BY savedate DESC) AS rn FROM projects_history_assignment ) SELECT projects_records.recordid, projects_records.recordtype, projects_recordtype_lu.recordtypedesc, projects_records.stage, projects_stage_lu.stagedesc, projects_records.position, projects_position_lu.positiondesc, CASE projects_records.clientrequested WHEN '1' THEN 'Yes' WHEN '0' THEN 'No' END AS clientrequested, projects_records.reportingmethod, projects_reportingmethod_lu.reportingmethoddesc, projects_records.clientaccess, projects_clientaccess_lu.clientaccessdesc, projects_records.clientnumber, projects_records.project, projects_lu.projectdesc, projects_records.version, projects_version_lu.versiondesc, projects_records.projectedversion, projects_version_lu_projected.versiondesc AS projectedversiondesc, projects_records.sitetype, projects_sitetype_lu.sitetypedesc, projects_records.title, projects_records.module, projects_module_lu.moduledesc, projects_records.component, projects_component_lu.componentdesc, projects_records.loginusername, projects_records.loginpassword, projects_records.assistedusername, projects_records.browsername, projects_browsername_lu.browsernamedesc, projects_records.browserversion, projects_records.osname, projects_osname_lu.osnamedesc, projects_records.osversion, projects_records.errortype, projects_errortype_lu.errortypedesc, projects_records.gsipriority, projects_gsipriority_lu.gsiprioritydesc, projects_records.clientpriority, projects_clientpriority_lu.clientprioritydesc, projects_records.scheduledstartdate, projects_records.scheduledcompletiondate, projects_records.projectedhours, projects_records.actualstartdate, projects_records.actualcompletiondate, projects_records.actualhours, CASE projects_records.billclient WHEN '1' THEN 'Yes' WHEN '0' THEN 'No' END AS billclient, projects_records.billamount, projects_records.status, projects_status_lu.statusdesc, CASE CAST(projects_records.assigned AS VARCHAR(5)) WHEN '0' THEN 'N/A' WHEN '10000' THEN 'Unassigned' WHEN '20000' THEN 'Client' WHEN '30000' THEN 'Tech Support' WHEN '40000' THEN 'LMI Tech Support' WHEN '50000' THEN 'Upload' WHEN '60000' THEN 'Spider' WHEN '70000' THEN 'DB Admin' ELSE rtrim(users_assigned.nickname) + ' ' + rtrim(users_assigned.lastname) END AS assigned, CASE CAST(projects_records.assigneddev AS VARCHAR(5)) WHEN '0' THEN 'N/A' WHEN '10000' THEN 'Unassigned' ELSE rtrim(users_assigneddev.nickname) + ' ' + rtrim(users_assigneddev.lastname) END AS assigneddev, CASE CAST(projects_records.assignedqa AS VARCHAR(5)) WHEN '0' THEN 'N/A' WHEN '10000' THEN 'Unassigned' ELSE rtrim(users_assignedqa.nickname) + ' ' + rtrim(users_assignedqa.lastname) END AS assignedqa, CASE CAST(projects_records.assignedsponsor AS VARCHAR(5)) WHEN '0' THEN 'N/A' WHEN '10000' THEN 'Unassigned' ELSE rtrim(users_assignedsponsor.nickname) + ' ' + rtrim(users_assignedsponsor.lastname) END AS assignedsponsor, projects_records.clientcreated, CASE projects_records.clientcreated WHEN '1' THEN 'Yes' WHEN '0' THEN 'No' END AS clientcreateddesc, CASE projects_records.clientcreated WHEN '1' THEN rtrim(clientusers_createuser.firstname) + ' ' + rtrim(clientusers_createuser.lastname) + ' (Client)' ELSE rtrim(users_createuser.nickname) + ' ' + rtrim(users_createuser.lastname) END AS createuser, projects_records.createdate, projects_records.savedate, projects_resolution.sitesaffected, projects_sitesaffected_lu.sitesaffecteddesc, DATEDIFF(DAY, projects_history_assignment.savedate, GETDATE()) as 'daysinqueue', projects_records.iOnHitList, projects_records.changetype FROM dbo.projects_records WITH (NOLOCK) LEFT OUTER JOIN dbo.projects_recordtype_lu WITH (NOLOCK) ON projects_records.recordtype = projects_recordtype_lu.recordtypeid LEFT OUTER JOIN dbo.projects_stage_lu WITH (NOLOCK) ON projects_records.stage = projects_stage_lu.stageid LEFT OUTER JOIN dbo.projects_position_lu WITH (NOLOCK) ON projects_records.position = projects_position_lu.positionid LEFT OUTER JOIN dbo.projects_reportingmethod_lu WITH (NOLOCK) ON projects_records.reportingmethod = projects_reportingmethod_lu.reportingmethodid LEFT OUTER JOIN dbo.projects_lu WITH (NOLOCK) ON projects_records.project = projects_lu.projectid LEFT OUTER JOIN dbo.projects_version_lu WITH (NOLOCK) ON projects_records.version = projects_version_lu.versionid LEFT OUTER JOIN dbo.projects_version_lu projects_version_lu_projected WITH (NOLOCK) ON projects_records.projectedversion = projects_version_lu_projected.versionid LEFT OUTER JOIN dbo.projects_sitetype_lu WITH (NOLOCK) ON projects_records.sitetype = projects_sitetype_lu.sitetypeid LEFT OUTER JOIN dbo.projects_module_lu WITH (NOLOCK) ON projects_records.module = projects_module_lu.moduleid LEFT OUTER JOIN dbo.projects_component_lu WITH (NOLOCK) ON projects_records.component = projects_component_lu.componentid LEFT OUTER JOIN dbo.projects_browsername_lu WITH (NOLOCK) ON projects_records.browsername = projects_browsername_lu.browsernameid LEFT OUTER JOIN dbo.projects_osname_lu WITH (NOLOCK) ON projects_records.osname = projects_osname_lu.osnameid LEFT OUTER JOIN dbo.projects_errortype_lu WITH (NOLOCK) ON projects_records.errortype = projects_errortype_lu.errortypeid LEFT OUTER JOIN dbo.projects_resolution WITH (NOLOCK) ON projects_records.recordid = projects_resolution.recordid LEFT OUTER JOIN dbo.projects_sitesaffected_lu WITH (NOLOCK) ON projects_resolution.sitesaffected = projects_sitesaffected_lu.sitesaffectedid LEFT OUTER JOIN dbo.projects_gsipriority_lu WITH (NOLOCK) ON projects_records.gsipriority = projects_gsipriority_lu.gsipriorityid LEFT OUTER JOIN dbo.projects_clientpriority_lu WITH (NOLOCK) ON projects_records.clientpriority = projects_clientpriority_lu.clientpriorityid LEFT OUTER JOIN dbo.projects_status_lu WITH (NOLOCK) ON projects_records.status = projects_status_lu.statusid LEFT OUTER JOIN dbo.projects_clientaccess_lu WITH (NOLOCK) ON projects_records.clientaccess = projects_clientaccess_lu.clientaccessid LEFT OUTER JOIN dbo.users users_assigned WITH (NOLOCK) ON projects_records.assigned = users_assigned.userid LEFT OUTER JOIN dbo.users users_assigneddev WITH (NOLOCK) ON projects_records.assigneddev = users_assigneddev.userid LEFT OUTER JOIN dbo.users users_assignedqa WITH (NOLOCK) ON projects_records.assignedqa = users_assignedqa.userid LEFT OUTER JOIN dbo.users users_assignedsponsor WITH (NOLOCK) ON projects_records.assignedsponsor = users_assignedsponsor.userid LEFT OUTER JOIN dbo.users users_createuser WITH (NOLOCK) ON projects_records.createuser = users_createuser.userid LEFT OUTER JOIN dbo.clientusers clientusers_createuser WITH (NOLOCK) ON projects_records.createuser = clientusers_createuser.userid LEFT OUTER JOIN dbo.projects_history_assignment WITH (NOLOCK) ON projects_history_assignment.recordid = projects_records.recordid AND projects_history_assignment.historyid = ( SELECT ro.historyid FROM rows rl CROSS APPLY ( SELECT TOP 1 rc.historyid FROM rows rc JOIN rows rn ON rn.recordid = rc.recordid AND rn.rn = rc.rn + 1 AND rn.assigned <> rc.assigned WHERE rc.recordid = rl.recordid ORDER BY rc.rn ) ro WHERE rl.rn = 1 AND rl.recordid = projects_records.recordid ) WHERE (@assignedtype='0' and projects_records.assigned = @assigned) OR (@assignedtype='1' and projects_records.assigneddev = @assigned) OR (@assignedtype='2' and projects_records.assignedqa = @assigned) OR (@assignedtype='3' and projects_records.assignedsponsor = @assigned) OR (@assignedtype='4' and projects_records.createuser = @assigned)

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  • HELP!! Delayed-job: Rake aborted! Can't modify frozen hash

    - by pmneve
    Too bad even the trace doesn't say which hash is involved. Sorry this post is long: am trying to provide enough context to be meaningful. Occurs intermittently when rake jobs:work is pulling a command out of delayed_jobs while my status observer is in the process of parsing a log file for detailed results of the previous delayed_job denizen. I have an observer class (in RAILS_ROOT/lib ) which listens for the events, makes a copy of them and calls the owner class ( in apps/models ) which then calls on the log parser (also in /lib) to do the actual work. (Should both of those classes, the observer and the parser be in app/models?) Am due to deliver this application in a few days and this is killing it (and me). Am using DirectoryWatcher to look for flag files that indicate the start and finish of the delayed_jobs. That is started at the end of environment.rb like this: require 'directory_watcher' $scriptStatusObserver = ScriptStatusObserver.new dirToWatch ="#{RAILS_ROOT}/tmp/flags" $directoryWatcher = DirectoryWatcher.new( dirToWatch ) $directoryWatcher.glob= "*.flg" $directoryWatcher.interval=(15) $directoryWatcher.add_observer( $scriptStatusObserver ) $directoryWatcher.persist=("#{RAILS_ROOT}/tmp/flags/dw_state.yml") $directoryWatcher.start at_exit { $directoryWatcher.stop } This code is outside of the run method (btw is that the best place or is inside the run better?) Here is the observer: require 'script_run' class ScriptStatusObserver def initialize @rcvdEvents = [] end def update( *events ) begin puts "#{LINE.to_s}: ScriptStatusObserver events: \n"+events.to_yaml cnt = 0 events.each do |e| if e.to_s.match(/^\s*added/) cnt = cnt + 1 @rcvdEvents << e end end ScriptRun.new.catch_up( @rcvdEvents ) if cnt > 0 @rcvdEvents.clear rescue puts $! end end end Here is ScriptRun (it attaches to an associative table built with has_many:through) require 'observer' class ScriptRun < ActiveRecord::Base set_table_name "scripts_runs" belongs_to :script belongs_to :run def parse( result ) parser = LogParser.new parser.parse(result) end def catch_up( events ) events.each do |e| typ = e.type path = e.path thisMatch = path.match(/flags\/(\d+)_(\d+)_([\d\.]+)_(\w+)\.flg/) run_id = thisMatch[1] script_id = thisMatch[2] ts = thisMatch[3] status = thisMatch[4] if e.to_s.match(/^\s*added/) status_update( script_id, run_id, status, ts, path ) end end end def status_update( script_id, run_id, status, ts, path ) scriptrun = ScriptRun.find(:first, :conditions => [ "run_id = ? and script_id = ?", run_id.to_i, script_id.to_i ]) if scriptrun.kind_of?(ScriptRun) currStatus = scriptrun.status if not currStatus == 'completed' scriptrun.update_attribute(:status, status) if status == 'parse' flag = File.new(path) logSpec = flag.gets flag.close logName = File.basename(logSpec) logPath = logSpec.sub(logName, '') logName =~ /^(([\w_]+)_([\w]+)_(\d+))\.log$/ name = $1 basename = $2 runenv = $3 tsOrPid = $4 result = Result.new result.log_path = logPath result.basename = basename result.name = name result.script_id = script_id.to_i result.run_id = run_id.to_i if runenv == 'sit' runenv = 'SIT3348' end result.application_environment_id = ApplicationEnvironment.find(:first, :conditions => [ "nodename = ?", runenv]).id parse(result) if run_completed?( run_id ) myRun = Run.find(run_id.to_i) if myRun.kind_of?( Run ) myRun.update_attribute( :completed, Time.now.to_f ) end end end end else puts "#{__LINE__.to_s}: ScriptRun.status_update: ScriptRun not found for run #{run_id} script #{script_id} ts #{ts.to_s}" end File.delete(path) end def run_completed?( id ) scriptruns = ScriptRun.find(:all, :conditions = [ "run_id = ?", id.to_i] ) scriptruns.each do |sr| if not sr.status == 'completed' return false end end return true end end LogParser is too long even for this post but it reads the script log and pulls detailed information (counts and timings) out of the log and writes to a details table. It also tallies and calculates averages and rolls those up into summary tables for quicker access from the web pages. Here is the error trace: (don't ask why everything is under my Windows profile. It's a long story) Scanner running 1270239731.43 directory_watcher.notify_observers: #, #] update:[#, /pneve/workspace/waftt-0.29/tmp/flags/100039_18_1270239550.108_parse.flg"] rake aborted! can't modify frozen hash C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:in []=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:inwrite_attribute_without_dirty' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/dirty.rb:139:in write_attribute' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:211:inlast_error=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:141:in handle_failed_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:115:inrun' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:162:in reserve_and_run_one_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:92:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:in times' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:66:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activesupport/ lib/active_support/core_ext/benchmark.rb:10:inrealtime' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:65:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:inloop' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/tasks.rb:13 c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:incall' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:597:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/1.8/monitor.rb:242:in synchronize ' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:590:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:583:in invoke' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2051:ininvoke_task' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:instandard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2023:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2001:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:in standard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:1998:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake: 31 c:/Documents and Settings/pneve/ruby/bin/rake:16:in `load' c:/Documents and Settings/pneve/ruby/bin/rake:16

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  • Questions related to writing your own file downloader using multiple threads java

    - by Shekhar
    Hello In my current company, i am doing a PoC on how we can write a file downloader utility. We have to use socket programming(TCP/IP) for downloading the files. One of the requirements of the client is that a file(which will be large in size) should be transfered in chunks for example if we have a file of 5Mb size then we can have 5 threads which transfer 1 Mb each. I have written a small application which downloads a file. You can download the eclipe project from http://www.fileflyer.com/view/QM1JSC0 A brief explanation of my classes FileSender.java This class provides the bytes of file. It has a method called sendBytesOfFile(long start,long end, long sequenceNo) which gives the number of bytes. import java.io.File; import java.io.IOException; import java.util.zip.CRC32; import org.apache.commons.io.FileUtils; public class FileSender { private static final String FILE_NAME = "C:\\shared\\test.pdf"; public ByteArrayWrapper sendBytesOfFile(long start,long end, long sequenceNo){ try { File file = new File(FILE_NAME); byte[] fileBytes = FileUtils.readFileToByteArray(file); System.out.println("Size of file is " +fileBytes.length); System.out.println(); System.out.println("Start "+start +" end "+end); byte[] bytes = getByteArray(fileBytes, start, end); ByteArrayWrapper wrapper = new ByteArrayWrapper(bytes, sequenceNo); return wrapper; } catch (IOException e) { throw new RuntimeException(e); } } private byte[] getByteArray(byte[] bytes, long start, long end){ long arrayLength = end-start; System.out.println("Start : "+start +" end : "+end + " Arraylength : "+arrayLength +" length of source array : "+bytes.length); byte[] arr = new byte[(int)arrayLength]; for(int i = (int)start, j =0; i < end;i++,j++){ arr[j] = bytes[i]; } return arr; } public static long fileSize(){ File file = new File(FILE_NAME); return file.length(); } } Second Class is FileReceiver.java - This class receives the file. Small Explanation what this file does This class finds the size of the file to be fetched from Sender Depending upon the size of the file it finds the start and end position till the bytes needs to be read. It starts n number of threads giving each thread start,end, sequence number and a list which all the threads share. Each thread reads the number of bytes and creates a ByteArrayWrapper. ByteArrayWrapper objects are added to the list Then i have while loop which basically make sure that all threads have done their work finally it sorts the list based on the sequence number. then the bytes are joined, and a complete byte array is formed which is converted to a file. Code of File Receiver package com.filedownloader; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.zip.CRC32; import org.apache.commons.io.FileUtils; public class FileReceiver { public static void main(String[] args) { FileReceiver receiver = new FileReceiver(); receiver.receiveFile(); } public void receiveFile(){ long startTime = System.currentTimeMillis(); long numberOfThreads = 10; long filesize = FileSender.fileSize(); System.out.println("File size received "+filesize); long start = filesize/numberOfThreads; List<ByteArrayWrapper> list = new ArrayList<ByteArrayWrapper>(); for(long threadCount =0; threadCount<numberOfThreads ;threadCount++){ FileDownloaderTask task = new FileDownloaderTask(threadCount*start,(threadCount+1)*start,threadCount,list); new Thread(task).start(); } while(list.size() != numberOfThreads){ // this is done so that all the threads should complete their work before processing further. //System.out.println("Waiting for threads to complete. List size "+list.size()); } if(list.size() == numberOfThreads){ System.out.println("All bytes received "+list); Collections.sort(list, new Comparator<ByteArrayWrapper>() { @Override public int compare(ByteArrayWrapper o1, ByteArrayWrapper o2) { long sequence1 = o1.getSequence(); long sequence2 = o2.getSequence(); if(sequence1 < sequence2){ return -1; }else if(sequence1 > sequence2){ return 1; } else{ return 0; } } }); byte[] totalBytes = list.get(0).getBytes(); byte[] firstArr = null; byte[] secondArr = null; for(int i = 1;i<list.size();i++){ firstArr = totalBytes; secondArr = list.get(i).getBytes(); totalBytes = concat(firstArr, secondArr); } System.out.println(totalBytes.length); convertToFile(totalBytes,"c:\\tmp\\test.pdf"); long endTime = System.currentTimeMillis(); System.out.println("Total time taken with "+numberOfThreads +" threads is "+(endTime-startTime)+" ms" ); } } private byte[] concat(byte[] A, byte[] B) { byte[] C= new byte[A.length+B.length]; System.arraycopy(A, 0, C, 0, A.length); System.arraycopy(B, 0, C, A.length, B.length); return C; } private void convertToFile(byte[] totalBytes,String name) { try { FileUtils.writeByteArrayToFile(new File(name), totalBytes); } catch (IOException e) { throw new RuntimeException(e); } } } Code of ByteArrayWrapper package com.filedownloader; import java.io.Serializable; public class ByteArrayWrapper implements Serializable{ private static final long serialVersionUID = 3499562855188457886L; private byte[] bytes; private long sequence; public ByteArrayWrapper(byte[] bytes, long sequenceNo) { this.bytes = bytes; this.sequence = sequenceNo; } public byte[] getBytes() { return bytes; } public long getSequence() { return sequence; } } Code of FileDownloaderTask import java.util.List; public class FileDownloaderTask implements Runnable { private List<ByteArrayWrapper> list; private long start; private long end; private long sequenceNo; public FileDownloaderTask(long start,long end,long sequenceNo,List<ByteArrayWrapper> list) { this.list = list; this.start = start; this.end = end; this.sequenceNo = sequenceNo; } @Override public void run() { ByteArrayWrapper wrapper = new FileSender().sendBytesOfFile(start, end, sequenceNo); list.add(wrapper); } } Questions related to this code 1) Does file downloading becomes fast when multiple threads is used? In this code i am not able to see the benefit. 2) How should i decide how many threads should i create ? 3) Are their any opensource libraries which does that 4) The file which file receiver receives is valid and not corrupted but checksum (i used FileUtils of common-io) does not match. Whats the problem? 5) This code gives out of memory when used with large file(above 100 Mb) i.e. because byte array which is created. How can i avoid? I know this is a very bad code but i have to write this in one day -:). Please suggest any other good way to do this? Thanks Shekhar

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  • HELP!! Rake aborted! Can't modify frozen hash

    - by pmneve
    Too bad even the trace doesn't say which hash is involved. Sorry this post is long: am trying to provide enough context to be meaningful. Occurs intermittently when rake jobs:work is pulling a command out of delayed_jobs while my status observer is in the process of parsing a log file for detailed results of the previous delayed_job denizen. I have an observer class (in RAILS_ROOT/lib ) which listens for the events, makes a copy of them and calls the owner class ( in apps/models ) which then calls on the log parser (also in /lib) to do the actual work. (Should both of those classes, the observer and the parser be in app/models?) Am due to deliver this application in a few days and this is killing it (and me). Am using DirectoryWatcher to look for flag files that indicate the start and finish of the delayed_jobs. That is started at the end of environment.rb like this: require 'directory_watcher' $scriptStatusObserver = ScriptStatusObserver.new dirToWatch ="#{RAILS_ROOT}/tmp/flags" $directoryWatcher = DirectoryWatcher.new( dirToWatch ) $directoryWatcher.glob= "*.flg" $directoryWatcher.interval=(15) $directoryWatcher.add_observer( $scriptStatusObserver ) $directoryWatcher.persist=("#{RAILS_ROOT}/tmp/flags/dw_state.yml") $directoryWatcher.start at_exit { $directoryWatcher.stop } This code is outside of the run method (btw is that the best place or is inside the run better?) Here is the observer: require 'script_run' class ScriptStatusObserver def initialize @rcvdEvents = [] end def update( *events ) begin puts "#{LINE.to_s}: ScriptStatusObserver events: \n"+events.to_yaml cnt = 0 events.each do |e| if e.to_s.match(/^\s*added/) cnt = cnt + 1 @rcvdEvents << e end end ScriptRun.new.catch_up( @rcvdEvents ) if cnt > 0 @rcvdEvents.clear rescue puts $! end end end Here is ScriptRun (it attaches to an associative table built with has_many:through) require 'observer' class ScriptRun < ActiveRecord::Base set_table_name "scripts_runs" belongs_to :script belongs_to :run def parse( result ) parser = LogParser.new parser.parse(result) end def catch_up( events ) events.each do |e| typ = e.type path = e.path thisMatch = path.match(/flags\/(\d+)_(\d+)_([\d\.]+)_(\w+)\.flg/) run_id = thisMatch[1] script_id = thisMatch[2] ts = thisMatch[3] status = thisMatch[4] if e.to_s.match(/^\s*added/) status_update( script_id, run_id, status, ts, path ) end end end def status_update( script_id, run_id, status, ts, path ) scriptrun = ScriptRun.find(:first, :conditions => [ "run_id = ? and script_id = ?", run_id.to_i, script_id.to_i ]) if scriptrun.kind_of?(ScriptRun) currStatus = scriptrun.status if not currStatus == 'completed' scriptrun.update_attribute(:status, status) if status == 'parse' flag = File.new(path) logSpec = flag.gets flag.close logName = File.basename(logSpec) logPath = logSpec.sub(logName, '') logName =~ /^(([\w_]+)_([\w]+)_(\d+))\.log$/ name = $1 basename = $2 runenv = $3 tsOrPid = $4 result = Result.new result.log_path = logPath result.basename = basename result.name = name result.script_id = script_id.to_i result.run_id = run_id.to_i if runenv == 'sit' runenv = 'SIT3348' end result.application_environment_id = ApplicationEnvironment.find(:first, :conditions => [ "nodename = ?", runenv]).id parse(result) if run_completed?( run_id ) myRun = Run.find(run_id.to_i) if myRun.kind_of?( Run ) myRun.update_attribute( :completed, Time.now.to_f ) end end end end else puts "#{__LINE__.to_s}: ScriptRun.status_update: ScriptRun not found for run #{run_id} script #{script_id} ts #{ts.to_s}" end File.delete(path) end def run_completed?( id ) scriptruns = ScriptRun.find(:all, :conditions = [ "run_id = ?", id.to_i] ) scriptruns.each do |sr| if not sr.status == 'completed' return false end end return true end end LogParser is too long even for this post but it reads the script log and pulls detailed information (counts and timings) out of the log and writes to a details table. It also tallies and calculates averages and rolls those up into summary tables for quicker access from the web pages. Here is the error trace: (don't ask why everything is under my Windows profile. It's a long story) Scanner running 1270239731.43 directory_watcher.notify_observers: #, #] update:[#, /pneve/workspace/waftt-0.29/tmp/flags/100039_18_1270239550.108_parse.flg"] rake aborted! can't modify frozen hash C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:in []=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:313:inwrite_attribute_without_dirty' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/dirty.rb:139:in write_attribute' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activerecord/l ib/active_record/attribute_methods.rb:211:inlast_error=' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:141:in handle_failed_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:115:inrun' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:162:in reserve_and_run_one_job' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:92:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:in times' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:91:inwork_off' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:66:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/rails/activesupport/ lib/active_support/core_ext/benchmark.rb:10:inrealtime' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:65:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:inloop' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/worker.rb:62:in start' C:/Documents and Settings/pneve/workspace/waftt-0.29/vendor/plugins/delayed_job/ lib/delayed/tasks.rb:13 c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:incall' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:636:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:631:in execute' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:597:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/1.8/monitor.rb:242:in synchronize ' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:590:ininvoke_with_call_chain' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:583:in invoke' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2051:ininvoke_task' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:ineach' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2029:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:instandard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2023:in top_level' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2001:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:2068:in standard_exception_handling' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake. rb:1998:inrun' c:/Documents and Settings/pneve/ruby/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake: 31 c:/Documents and Settings/pneve/ruby/bin/rake:16:in `load' c:/Documents and Settings/pneve/ruby/bin/rake:16

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  • Autocorrelation returns random results with mic input (using a high pass filter)

    - by Niall
    Hello, Sorry to ask a similar question to the one i asked before (FFT Problem (Returns random results)), but i've looked up pitch detection and autocorrelation and have found some code for pitch detection using autocorrelation. Im trying to do pitch detection of a users singing. Problem is, it keeps returning random results. I've got some code from http://code.google.com/p/yaalp/ which i've converted to C++ and modified (below). My sample rate is 2048, and data size is 1024. I'm detecting pitch of both a sine wave and mic input. The frequency of the sine wave is 726.0, and its detecting it to be 722.950820 (which im ok with), but its detecting the pitch of the mic as a random number from around 100 to around 1050. I'm now using a High pass filter to remove the DC offset, but it's not working. Am i doing it right, and if so, what else can i do to fix it? Any help would be greatly appreciated! double* doHighPassFilter(short *buffer) { // Do FFT: int bufferLength = 1024; float *real = malloc(bufferLength*sizeof(float)); float *real2 = malloc(bufferLength*sizeof(float)); for(int x=0;x<bufferLength;x++) { real[x] = buffer[x]; } fft(real, bufferLength); for(int x=0;x<bufferLength;x+=2) { real2[x] = real[x]; } for (int i=0; i < 30; i++) //Set freqs lower than 30hz to zero to attenuate the low frequencies real2[i] = 0; // Do inverse FFT: inversefft(real2,bufferLength); double* real3 = (double*)real2; return real3; } double DetectPitch(short* data) { int sampleRate = 2048; //Create sine wave double *buffer = malloc(1024*sizeof(short)); double amplitude = 0.25 * 32768; //0.25 * max length of short double frequency = 726.0; for (int n = 0; n < 1024; n++) { buffer[n] = (short)(amplitude * sin((2 * 3.14159265 * n * frequency) / sampleRate)); } doHighPassFilter(data); printf("Pitch from sine wave: %f\n",detectPitchCalculation(buffer, 50.0, 1000.0, 1, 1)); printf("Pitch from mic: %f\n",detectPitchCalculation(data, 50.0, 1000.0, 1, 1)); return 0; } // These work by shifting the signal until it seems to correlate with itself. // In other words if the signal looks very similar to (signal shifted 200 data) than the fundamental period is probably 200 data // Note that the algorithm only works well when there's only one prominent fundamental. // This could be optimized by looking at the rate of change to determine a maximum without testing all periods. double detectPitchCalculation(double* data, double minHz, double maxHz, int nCandidates, int nResolution) { //-------------------------1-------------------------// // note that higher frequency means lower period int nLowPeriodInSamples = hzToPeriodInSamples(maxHz, 2048); int nHiPeriodInSamples = hzToPeriodInSamples(minHz, 2048); if (nHiPeriodInSamples <= nLowPeriodInSamples) printf("Bad range for pitch detection."); if (1024 < nHiPeriodInSamples) printf("Not enough data."); double *results = new double[nHiPeriodInSamples - nLowPeriodInSamples]; //-------------------------2-------------------------// for (int period = nLowPeriodInSamples; period < nHiPeriodInSamples; period += nResolution) { double sum = 0; // for each sample, find correlation. (If they are far apart, small) for (int i = 0; i < 1024 - period; i++) sum += data[i] * data[i + period]; double mean = sum / 1024.0; results[period - nLowPeriodInSamples] = mean; } //-------------------------3-------------------------// // find the best indices int *bestIndices = findBestCandidates(nCandidates, results, nHiPeriodInSamples - nLowPeriodInSamples - 1); //note findBestCandidates modifies parameter // convert back to Hz double *res = new double[nCandidates]; for (int i=0; i < nCandidates;i++) res[i] = periodInSamplesToHz(bestIndices[i]+nLowPeriodInSamples, 2048); double pitch2 = res[0]; free(res); free(results); return pitch2; } /// Finds n "best" values from an array. Returns the indices of the best parts. /// (One way to do this would be to sort the array, but that could take too long. /// Warning: Changes the contents of the array!!! Do not use result array afterwards. int* findBestCandidates(int n, double* inputs,int length) { //int length = inputs.Length; if (length < n) printf("Length of inputs is not long enough."); int *res = new int[n]; double minValue = 0; for (int c = 0; c < n; c++) { // find the highest. double fBestValue = minValue; int nBestIndex = -1; for (int i = 0; i < length; i++) { if (inputs[i] > fBestValue) { nBestIndex = i; fBestValue = inputs[i]; } } // record this highest value res[c] = nBestIndex; // now blank out that index. if(nBestIndex!=-1) inputs[nBestIndex] = minValue; } return res; } int hzToPeriodInSamples(double hz, int sampleRate) { return (int)(1 / (hz / (double)sampleRate)); } double periodInSamplesToHz(int period, int sampleRate) { return 1 / (period / (double)sampleRate); } Thanks, Niall. Edit: Changed the code to implement a high pass filter with a cutoff of 30hz (from What Are High-Pass and Low-Pass Filters?, can anyone tell me how to convert the low-pass filter using convolution to a high-pass one?) but it's still returning random results. Plugging it into a VST host and using VST plugins to compare spectrums isn't an option to me unfortunately.

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  • Implementing a robust async stream reader

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output, but that is a detail and does not play an important role. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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  • WCF timeout exception detailed investigation

    - by Jason Kealey
    We have an application that has a WCF service (*.svc) running on IIS7 and various clients querying the service. The server is running Win 2008 Server. The clients are running either Windows 2008 Server or Windows 2003 server. I am getting the following exception, which I have seen can in fact be related to a large number of potential WCF issues. System.TimeoutException: The request channel timed out while waiting for a reply after 00:00:59.9320000. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. ---> System.TimeoutException: The HTTP request to 'http://www.domain.com/WebServices/myservice.svc/gzip' has exceeded the allotted timeout of 00:01:00. The time allotted to this operation may have been a portion of a longer timeout. I have increased the timeout to 30min and the error still occurred. This tells me that something else is at play, because the quantity of data could never take 30min to upload or download. The error comes and goes. At the moment, it is more frequent. It does not seem to matter if I have 3 clients running simultaneously or 100, it still occurs once in a while. Most of the time, there are no timeouts but I still get a few per hour. The error comes from any of the methods that are invoked. One of these methods does not have parameters and returns a bit of data. Another takes in lots of data as a parameter but executes asynchronously. The errors always originate from the client and never reference any code on the server in the stack trace. It always ends with: at System.Net.HttpWebRequest.GetResponse() at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) On the server: I've tried (and currently have) the following binding settings: maxBufferSize="2147483647" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" It does not seem to have an impact. I've tried (and currently have) the following throttling settings: <serviceThrottling maxConcurrentCalls="1500" maxConcurrentInstances="1500" maxConcurrentSessions="1500"/> It does not seem to have an impact. I currently have the following settings for the WCF service. [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Single)] I ran with ConcurrencyMode.Multiple for a while, and the error still occurred. I've tried restarting IIS, restarting my underlying SQL Server, restarting the machine. All of these don't seem to have an impact. I've tried disabling the Windows firewall. It does not seem to have an impact. On the client, I have these settings: maxReceivedMessageSize="2147483647" <system.net> <connectionManagement> <add address="*" maxconnection="16"/> </connectionManagement> </system.net> My client closes its connections: var client = new MyClient(); try { return client.GetConfigurationOptions(); } finally { client.Close(); } I have changed the registry settings to allow more outgoing connections: MaxConnectionsPerServer=24, MaxConnectionsPer1_0Server=32. I have now just recently tried SvcTraceViewer.exe. I managed to catch one exception on the client end. I see that its duration is 1 minute. Looking at the server side trace, I can see that the server is not aware of this exception. The maximum duration I can see is 10 seconds. I have looked at active database connections using exec sp_who on the server. I only have a few (2-3). I have looked at TCP connections from one client using TCPview. It usually is around 2-3 and I have seen up to 5 or 6. Simply put, I am stumped. I have tried everything I could find, and must be missing something very simple that a WCF expert would be able to see. It is my gut feeling that something is blocking my clients at the low-level (TCP), before the server actually receives the message and/or that something is queuing the messages at the server level and never letting them process. If you have any performance counters I should look at, please let me know. (please indicate what values are bad, as some of these counters are hard to decypher). Also, how could I log the WCF message size? Finally, are there any tools our there that would allow me to test how many connections I can establish between my client and server (independently from my application) Thanks for your time! Extra information added June 20th: My WCF application does something similar to the following. while (true) { Step1GetConfigurationSettingsFromServerViaWCF(); // can change between calls Step2GetWorkUnitFromServerViaWCF(); DoWorkLocally(); // takes 5-15minutes. Step3SendBackResultsToServerViaWCF(); } Using WireShark, I did see that when the error occurs, I have a five TCP retransmissions followed by a TCP reset later on. My guess is the RST is coming from WCF killing the connection. The exception report I get is from Step3 timing out. I discovered this by looking at the tcp stream "tcp.stream eq 192". I then expanded my filter to "tcp.stream eq 192 and http and http.request.method eq POST" and saw 6 POSTs during this stream. This seemed odd, so I checked with another stream such as tcp.stream eq 100. I had three POSTs, which seems a bit more normal because I am doing three calls. However, I do close my connection after every WCF call, so I would have expected one call per stream (but I don't know much about TCP). Investigating a bit more, I dumped the http packet load to disk to look at what these six calls where. 1) Step3 2) Step1 3) Step2 4) Step3 - corrupted 5) Step1 6) Step2 My guess is two concurrent clients are using the same connection, that is why I saw duplicates. However, I still have a few more issues that I can't comprehend: a) Why is the packet corrupted? Random network fluke - maybe? The load is gzipped using this sample code: http://msdn.microsoft.com/en-us/library/ms751458.aspx - Could the code be buggy once in a while when used concurrently? I should test without the gzip library. b) Why would I see step 1 & step 2 running AFTER the corrupted operation timed out? It seems to me as if these operations should not have occurred. Maybe I am not looking at the right stream because my understanding of TCP is flawed. I have other streams that occur at the same time. I should investigate other streams - a quick glance at streams 190-194 show that the Step3 POST have proper payload data (not corrupted). Pushing me to look at the gzip library again.

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  • Will these optimizations to my Ruby implementation of diff improve performance in a Rails app?

    - by grg-n-sox
    <tl;dr> In source version control diff patch generation, would it be worth it to use the optimizations listed at the very bottom of this writing (see <optimizations>) in my Ruby implementation of diff for making diff patches? </tl;dr> <introduction> I am programming something I have never done before and there might already be tools out there to do the exact thing I am programming but at this point I am having too much fun to care so I am still going to do it from scratch, even if there is a tool for this. So anyways, I am working on a Ruby on Rails app and need a certain feature. Basically I want each entry in a table of mine, let's say for example a table of video games, to have a stored chunk of text that represents a review or something of the sort for that table entry. However, I want this text to be both editable by any registered user and also keep track of different submissions in a version control system. The simplest solution I could think of is just implement a solution that keeps track of the text body and the diff patch history of different versions of the text body as objects in Ruby and then serialize it, preferably in human readable form (so I'll most likely use YAML for this) for editing if needed due to corruption by a software bug or a mistake is made by an admin doing some version editing. So at first I just tried to dive in head first into this feature to find that the problem of generating a diff patch is more difficult that I thought to do efficiently. So I did some research and came across some ideas. Some I have implemented already and some I have not. However, it all pretty much revolves around the longest common subsequence problem, as you would already know if you have already done anything with diff or diff-like features, and optimization the function that solves it. Currently I have it so it truncates the compared versions of the text body from the beginning and end until non-matching lines are found. Then it solves the problem using a comparison matrix, but instead of incrementing the value stored in a cell when it finds a matching line like in most longest common subsequence algorithms I have seen examples of, I increment when I have a non-matching line so as to calculate edit distance instead of longest common subsequence. Although as far as I can tell between the two approaches, they are essentially two sides of the same coin so either could be used to derive an answer. It then back-traces through the comparison matrix and notes when there was an incrementation and in which adjacent cell (West, Northwest, or North) to determine that line's diff entry and assumes all other lines to be unchanged. Normally I would leave it at that, but since this is going into a Rails environment and not just some stand-alone Ruby script, I started getting worried about needing to optimize at least enough so if a spammer that somehow knew how I implemented the version control system and knew my worst case scenario entry still wouldn't be able to hit the server that bad. After some searching and reading of research papers and articles through the internet, I've come across several that seem decent but all seem to have pros and cons and I am having a hard time deciding how well in this situation that the pros and cons balance out. So are the ones listed here worth it? I have listed them with known pros and cons. </introduction> <optimizations> Chop the compared sequences into multiple chucks of subsequences by splitting where lines are unchanged, and then truncating each section of unchanged lines at the beginning and end of each section. Then solve the edit distance of each subsequence. Pro: Changes the time increase as the changed area gets bigger from a quadratic increase to something more similar to a linear increase. Con: Figuring out where to split already seems like you have to solve edit distance except now you don't care how it is changed. Would be fine if this was solvable by a process closer to solving hamming distance but a single insertion would throw this off. Use a cryptographic hash function to both convert all sequence elements into integers and ensure uniqueness. Then solve the edit distance comparing the hash integers instead of the sequence elements themselves. Pro: The operation of comparing two integers is faster than the operation of comparing two strings, so a slight performance gain is received after every comparison, which can be a lot overall. Con: Using a cryptographic hash function takes time to convert all the sequence elements and may end up costing more time to do the conversion that you gain back from the integer comparisons. You could use the built in hash function for a string but that will not guarantee uniqueness. Use lazy evaluation to only calculate the three center-most diagonals of the comparison matrix and then only calculate additional diagonals as needed. And then also use this approach to possibly remove the need on some comparisons to compare all three adjacent cells as desribed here. Pro: Can turn an algorithm that always takes O(n * m) time and make it so only worst case scenario is that time, best case becomes practically linear, and average case is somewhere between the two. Con: It is an algorithm I've only seen implemented in functional programming languages and I am having a difficult time comprehending how to convert this into Ruby based on how it is described at the site linked to above. Make a C module and do the hard work at the native level in C and just make a Ruby wrapper for it so Ruby can make all the calls to it that it needs. Pro: I have to imagine that evaluating something like this in could be a LOT faster. Con: I have no idea how Rails handles apps with ruby code that has C extensions and it hurts the portability of the app. This is an optimization for after the solving of edit distance, but idea is to store additional combined diffs with the ones produced by each version to make a delta-tree data structure with the most recently made diff as the root node of the tree so getting to any version takes worst case time of O(log n) instead of O(n). Pro: Would make going back to an old version a lot faster. Con: It would mean every new commit, the delta-tree would get a new root node that will cost time to reorganize the delta-tree for an operation that will be carried out a lot more often than going back a version, not to mention the unlikelihood it will be an old version. </optimizations> So are these things worth the effort?

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  • PHP inserting Apostrophes where it shouldn't

    - by Jack W-H
    Hi folks Not too sure what's going on here as this doesn't seem like standard practise to me. But basically I have a basic database thingy going on that lets users submit code snippets. They can provide up to 5 tags for their submission. Now I'm still learning so please forgive me if this is obvious! Here's the PHP script that makes it all work (note there may be some CodeIgniter specific functions in there): function submitform() { $this->load->helper(array('form', 'url')); $this->load->library('form_validation'); $this->load->database(); $this->form_validation->set_error_delimiters('<p style="color:#FF0000;">', '</p>'); $this->form_validation->set_rules('title', 'Title', 'trim|required|min_length[5]|max_length[255]|xss_clean'); $this->form_validation->set_rules('summary', 'Summary', 'trim|required|min_length[5]|max_length[255]|xss_clean'); $this->form_validation->set_rules('bbcode', 'Code', 'required|min_length[5]'); // No XSS clean (or <script> tags etc. are gone) $this->form_validation->set_rules('tags', 'Tags', 'trim|xss_clean|required|max_length[254]'); if ($this->form_validation->run() == FALSE) { // Do some stuff if it fails } else { // User's input values $title = $this->db->escape(set_value('title')); $summary = $this->db->escape(set_value('summary')); $code = $this->db->escape(set_value('bbcode')); $tags = $this->db->escape(set_value('tags')); // Stop things like <script> tags working $codesanitised = htmlspecialchars($code); // Other values to be entered $author = $this->tank_auth->get_user_id(); $bi1 = ""; $bi2 = ""; // This long messy bit basically sees which browsers the code is compatible with. if (isset($_POST['IE6'])) {$bi1 .= "IE6, "; $bi2 .= "1, ";} else {$bi1 .= "IE6, "; $bi2 .= "NULL, ";} if (isset($_POST['IE7'])) {$bi1 .= "IE7, "; $bi2 .= "1, ";} else {$bi1 .= "IE7, "; $bi2 .= "NULL, ";} if (isset($_POST['IE8'])) {$bi1 .= "IE8, "; $bi2 .= "1, ";} else {$bi1 .= "IE8, "; $bi2 .= "NULL, ";} if (isset($_POST['FF2'])) {$bi1 .= "FF2, "; $bi2 .= "1, ";} else {$bi1 .= "FF2, "; $bi2 .= "NULL, ";} if (isset($_POST['FF3'])) {$bi1 .= "FF3, "; $bi2 .= "1, ";} else {$bi1 .= "FF3, "; $bi2 .= "NULL, ";} if (isset($_POST['SA3'])) {$bi1 .= "SA3, "; $bi2 .= "1, ";} else {$bi1 .= "SA3, "; $bi2 .= "NULL, ";} if (isset($_POST['SA4'])) {$bi1 .= "SA4, "; $bi2 .= "1, ";} else {$bi1 .= "SA4, "; $bi2 .= "NULL, ";} if (isset($_POST['CHR'])) {$bi1 .= "CHR, "; $bi2 .= "1, ";} else {$bi1 .= "CHR, "; $bi2 .= "NULL, ";} if (isset($_POST['OPE'])) {$bi1 .= "OPE, "; $bi2 .= "1, ";} else {$bi1 .= "OPE, "; $bi2 .= "NULL, ";} if (isset($_POST['OTH'])) {$bi1 .= "OTH, "; $bi2 .= "1, ";} else {$bi1 .= "OTH, "; $bi2 .= "NULL, ";} // $b1 is $bi1 without the last two characters (, ) which would cause a query error $b1 = substr($bi1, 0, -2); $b2 = substr($bi2, 0, -2); // :::::::::::THIS IS WHERE THE IMPORTANT STUFF IS, STACKOVERFLOW READERS:::::::::: // Split up all the words in $tags into individual variables - each tag is seperated with a space $pieces = explode(" ", $tags); // Usage: // echo $pieces[0]; // piece1 etc $ti1 = ""; $ti2 = ""; // Now we'll do similar to what we did with the compatible browsers to generate a bit of a query string if ($pieces[0]!=NULL) {$ti1 .= "tag1, "; $ti2 .= "$pieces[0], ";} else {$ti1 .= "tag1, "; $ti2 .= "NULL, ";} if ($pieces[1]!=NULL) {$ti1 .= "tag2, "; $ti2 .= "$pieces[1], ";} else {$ti1 .= "tag2, "; $ti2 .= "NULL, ";} if ($pieces[2]!=NULL) {$ti1 .= "tag3, "; $ti2 .= "$pieces[2], ";} else {$ti1 .= "tag3, "; $ti2 .= "NULL, ";} if ($pieces[3]!=NULL) {$ti1 .= "tag4, "; $ti2 .= "$pieces[3], ";} else {$ti1 .= "tag4, "; $ti2 .= "NULL, ";} if ($pieces[4]!=NULL) {$ti1 .= "tag5, "; $ti2 .= "$pieces[4], ";} else {$ti1 .= "tag5, "; $ti2 .= "NULL, ";} $t1 = substr($ti1, 0, -2); $t2 = substr($ti2, 0, -2); $sql = "INSERT INTO code (id, title, author, summary, code, date, $t1, $b1) VALUES ('', $title, $author, $summary, $codesanitised, NOW(), $t2, $b2)"; $this->db->query($sql); $this->load->view('subviews/template/headerview'); $this->load->view('subviews/template/menuview'); $this->load->view('subviews/template/sidebar'); $this->load->view('thanksforsubmission'); $this->load->view('subviews/template/footerview'); } } Sorry about that boring drivel of code there. I realise I probably have a few bad practises in there - please point them out if so. This is what the outputted query looks like (it results in an error and isn't queried at all): A Database Error Occurred Error Number: 1136 Column count doesn't match value count at row 1 INSERT INTO code (id, title, author, summary, code, date, tag1, tag2, tag3, tag4, tag5, IE6, IE7, IE8, FF2, FF3, SA3, SA4, CHR, OPE, OTH) VALUES ('', 'test2', 1, 'test2', 'test2 ', NOW(), 'test2, test2, test2, test2, test2', NULL, NULL, 1, 1, 1, 1, 1, 1, 1, NULL) You'll see at the bit after NOW(), 'test2, test2, test2, test2, test2' - I never asked it to put all that in apostrophes. Did I? What I could do is put each of those lines like this: if ($pieces[0]!=NULL) {$ti1 .= "tag1, "; $ti2 .= "'$pieces[0]', ";} else {$ti1 .= "tag1, "; $ti2 .= "NULL, ";} With single quotes around $pieces[0] etc. - but then my problem is that this kinda fails when the user only enters 4 tags, or 3, or whatever. Sorry if that's the worst phrased question in history, I tried, but my brain has turned to mush. Thanks for your help! Jack

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  • XMLReader mysteriously fails when parsing document

    - by Valrus
    I have a php script that takes in some XML data and parses it, displaying various bits of information I pull out of it. This has been working fine for over 6 months, until recently it now fails mysteriously on a certain tag. The XML is generated from an outside source(a conferencing bridge), so I have no control over how it is built. I have put the xml through an online validator and it returned no errors. The code also works fine when I connect to another conferencing bridge and get the same output. I have been using XMLReader class so far and tried switching to SmipleXML, but it fails when I create the SimpleXML object using the data. Here is the snippet of where it fails while parsing: <CDR_SUMMARY> <FILE_VERSION>1001</FILE_VERSION> <NAME>Conference Title Hidden</NAME> <ID>10227</ID> <STATUS_STR>Auto_termination,_everybody_quit</STATUS_STR> <STATUS>4</STATUS> <GMT_OFFSET>-4</GMT_OFFSET> <START_TIME>2010-04-14T15:00:33</START_TIME> <DURATION> <HOUR>0</HOUR> <MINUTE>39</MINUTE> <SECOND>37</SECOND> </DURATION> <RESERVE_START_TIME>2010-04-14T15:00:33</RESERVE_START_TIME> <RESERVE_DURATION> <HOUR>12</HOUR> <MINUTE>0</MINUTE> <SECOND>0</SECOND> </RESERVE_DURATION> <MCU_FILE_NAME>c11</MCU_FILE_NAME> <FILE_SAVED>0</FILE_SAVED> <GMT_OFFSET_MINUTE>0</GMT_OFFSET_MINUTE> </CDR_SUMMARY> The <SOUND> opening tag is the last one read before failing. And this is my code: `public function processResponse($xml) { print "Processing List..."; $reader = new XMLReader($xml); try { $reader->setSchema("./schemas/response_trans_cdr_list.xsd"); } catch(Exception $e) { print "Exception:".$e->getMessage(); } //verify xml if($reader->xml($xml)) { while($reader->read()) { //$currentstring = $reader->readstring(); if($reader->name === "ACTION") { //into meat of resposnse while($reader->read()) { //print "Looping..."; //$currentstring = $reader->readInnerXML(); //print $currentstring; if($reader->nodeType == XMLReader::ELEMENT) { if($reader->name === "ID") { $this->conferenceIDs[$this->counter] = $reader->readString(); print "<BR>Conf ID found: ".$this->counter." ID: ".$this->conferenceIDs[$this->counter]; $this->counter += 1; } else if($reader->name === "START_TIME") { //conference start time. print "<BR>Start Time Found! "; $this->conferenceStarts[$this->counter-1] = $reader->readString(); } else if($reader->name === "NAME") { print "<BR> Name Found!"; $this->conferenceNames[$this->counter] = $reader->readString(); } else if($reader->name === "MCU_FILE_NAME") { print "<BR> MCU_FILE_NAME Found!"; //print $this->counter." File Name: ".$reader->readstring()."<BR>"; } else if($reader->name === "RESERVE_START_TIME") { print "<BR> RESERVE_START_TIME Found!"; } else if($reader->name === "FILE_VERSION") { print "<BR> FILE_VERSION Found!"; } else if($reader->name === "STATUS_STR") { print "<BR> STATUS_STR Found!"; } else if($reader->name === "STATUS") { print "<BR> STATUS Found!"; } else if($reader->name === "GMT_OFFSET") { print "<BR> GMT_OFFSET Found!"; } else if($reader->name === "DURATION") { print "<BR> DURATION Found!"; } else if($reader->name === "RESERVE_START_TIME") { print "<BR> RESERVE_START_TIME Found!"; } else if($reader->name === "RESERVE_DURATION") { print "<BR> RESERVE_DURATION Found!"; } else if($reader->name === "FILE_SAVED") { print "<BR> FILE_SAVED Found!"; } else if($reader->name === "GMT_OFFSET_MINUTE") { print "<BR> GMT_OFFSET_MINUTE Found!"; } else if($reader->name === "HOUR") { print "<BR> HOUR Found!"; } else if($reader->name === "MINUTE") { print "<BR> MINUTE Found!"; } else if($reader->name === "SECOND") { print "<BR> SECOND Found!"; } }else if($reader->nodeType == XMLReader::END_ELEMENT) { print "Close Element".$reader->name; } } print "End Action Loop"; } } } else { print "Error reading response: Bad XML returned"; } }` Anyone have any ideas what could be causing this failure? the code exits gracefully and I see the "End Action Loop" message in my output. It's like it just spontaneously exits the loop.

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  • Is this too much code for a header only library?

    - by Billy ONeal
    It seems like I had to inline quite a bit of code here. I'm wondering if it's bad design practice to leave this entirely in a header file like this: #pragma once #include <string> #include <boost/noncopyable.hpp> #include <boost/make_shared.hpp> #include <boost/iterator/iterator_facade.hpp> #include <Windows.h> #include "../Exception.hpp" namespace WindowsAPI { namespace FileSystem { class FileData; struct AllResults; struct FilesOnly; template <typename Filter_T = AllResults> class DirectoryIterator; namespace detail { class DirectoryIteratorImpl : public boost::noncopyable { WIN32_FIND_DATAW currentData; HANDLE hFind; std::wstring root; public: inline DirectoryIteratorImpl(); inline explicit DirectoryIteratorImpl(const std::wstring& pathSpec); inline void increment(); inline bool equal(const DirectoryIteratorImpl& other) const; inline const std::wstring& GetPathRoot() const; inline const WIN32_FIND_DATAW& GetCurrentFindData() const; inline ~DirectoryIteratorImpl(); }; } class FileData //Serves as a proxy to the WIN32_FIND_DATA struture inside the iterator. { boost::shared_ptr<detail::DirectoryIteratorImpl> iteratorSource; public: FileData(const boost::shared_ptr<detail::DirectoryIteratorImpl>& parent) : iteratorSource(parent) {}; DWORD GetAttributes() const { return iteratorSource->GetCurrentFindData().dwFileAttributes; }; bool IsDirectory() const { return (GetAttributes() | FILE_ATTRIBUTE_DIRECTORY) != 0; }; bool IsFile() const { return !IsDirectory(); }; bool IsArchive() const { return (GetAttributes() | FILE_ATTRIBUTE_ARCHIVE) != 0; }; bool IsReadOnly() const { return (GetAttributes() | FILE_ATTRIBUTE_READONLY) != 0; }; unsigned __int64 GetSize() const { ULARGE_INTEGER intValue; intValue.LowPart = iteratorSource->GetCurrentFindData().nFileSizeLow; intValue.HighPart = iteratorSource->GetCurrentFindData().nFileSizeHigh; return intValue.QuadPart; }; std::wstring GetFolderPath() const { return iteratorSource->GetPathRoot(); }; std::wstring GetFileName() const { return iteratorSource->GetCurrentFindData().cFileName; }; std::wstring GetFullFileName() const { return GetFolderPath() + GetFileName(); }; std::wstring GetShortFileName() const { return iteratorSource->GetCurrentFindData().cAlternateFileName; }; FILETIME GetCreationTime() const { return iteratorSource->GetCurrentFindData().ftCreationTime; }; FILETIME GetLastAccessTime() const { return iteratorSource->GetCurrentFindData().ftLastAccessTime; }; FILETIME GetLastWriteTime() const { return iteratorSource->GetCurrentFindData().ftLastWriteTime; }; }; struct AllResults : public std::unary_function<const FileData&, bool> { bool operator()(const FileData&) { return true; }; }; struct FilesOnly : public std::unary_function<const FileData&, bool> { bool operator()(const FileData& arg) { return arg.IsFile(); }; }; template <typename Filter_T> class DirectoryIterator : public boost::iterator_facade<DirectoryIterator<Filter_T>, const FileData, std::input_iterator_tag> { friend class boost::iterator_core_access; boost::shared_ptr<detail::DirectoryIteratorImpl> impl; FileData current; Filter_T filter; void increment() { do { impl->increment(); } while (! filter(current)); }; bool equal(const DirectoryIterator& other) const { return impl->equal(*other.impl); }; const FileData& dereference() const { return current; }; public: DirectoryIterator(Filter_T functor = Filter_T()) : impl(boost::make_shared<detail::DirectoryIteratorImpl>()), current(impl), filter(functor) { }; explicit DirectoryIterator(const std::wstring& pathSpec, Filter_T functor = Filter_T()) : impl(boost::make_shared<detail::DirectoryIteratorImpl>(pathSpec)), current(impl), filter(functor) { }; }; namespace detail { DirectoryIteratorImpl::DirectoryIteratorImpl() : hFind(INVALID_HANDLE_VALUE) { } DirectoryIteratorImpl::DirectoryIteratorImpl(const std::wstring& pathSpec) { std::wstring::const_iterator lastSlash = std::find(pathSpec.rbegin(), pathSpec.rend(), L'\\').base(); root.assign(pathSpec.begin(), lastSlash); hFind = FindFirstFileW(pathSpec.c_str(), &currentData); if (hFind == INVALID_HANDLE_VALUE) WindowsApiException::ThrowFromLastError(); while (!wcscmp(currentData.cFileName, L".") || !wcscmp(currentData.cFileName, L"..")) { increment(); } } void DirectoryIteratorImpl::increment() { BOOL success = FindNextFile(hFind, &currentData); if (success) return; DWORD error = GetLastError(); if (error == ERROR_NO_MORE_FILES) { FindClose(hFind); hFind = INVALID_HANDLE_VALUE; } else { WindowsApiException::Throw(error); } } DirectoryIteratorImpl::~DirectoryIteratorImpl() { if (hFind != INVALID_HANDLE_VALUE) FindClose(hFind); } bool DirectoryIteratorImpl::equal(const DirectoryIteratorImpl& other) const { if (this == &other) return true; return hFind == other.hFind; } const std::wstring& DirectoryIteratorImpl::GetPathRoot() const { return root; } const WIN32_FIND_DATAW& DirectoryIteratorImpl::GetCurrentFindData() const { return currentData; } } }}

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  • Implementing a robust async stream reader for a console

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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