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  • Very high Magento/Apache memory usage even without visitors (are we fooled by our hosting company?)

    - by MrDobalina
    I am no server guy and we have issues with our speed so I come here asking for advise. We have a VPS with 2 cores and 2gb of RAM at a Magento specialized hosting company. Over the course of the last weeks our site speed has gotten worse, even though our store is new, has less than 1000 SKUs and not even 100 visitos a day. At magespeedtest.com we only get 1.87 trans/sec @ 2.11 secs each with a mere 5 concurrent users. Our magento log files are clean, we have no huge database tables or anything like that. When we take a look at our server real time stats, we see that the memory usage jumped up from about 34% to 71% and now 82% in just a few days in idle, with no visitors on the site. Our hosting company said that we do not need to worry about that as it`s maybe related to mysql which creates buffers (which are maybe not even actually being used) and what is important is CPU and swap - stats are ok here. They also said that the low benchmark scores are caused by bad extensions or template modifications on our side. We are not sure if we can trust that statement as we only have 4 plugins installed (all from aheadworks and amasty which are known to be one of the best magento extension developers). Our template modifications are purely html and css, no modifications to the php code. Our pagespeed is ranked with 93/100 in firebug and Magento is properly configured, so the problem really just gets obvious when there are a handful of users on the site at the same time. Can anyone confirm our hosting`s statement about memory usage and where can I start looking for a solution?

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  • building a debian base image

    - by Michael
    Is there a preferred way to create base images for Debian-based customized installations? We are currently going with multistrap but although it's better than hand-crafted chroot stuff, it still has a lot of edges and corners. Is there a more reliable and less error-prone way to produce a root filesystem of a Debian installation with some additional .debs installed? (I don't want to send out a Debian installer with a preseed file though.) Addendum 1: To clarify things a bit: We are delivering some kind of software appliance to our customers. That is, a debian operating system, with some additional software packages -- both our own and third-party ones -- and some configuration changes. To ease the installation process, we have an installer that does nothing more than partitioning, copying files to the partitions and setting up grub. So it's basically an image-based installer. So we are basically running the debian installation ourselves and just distribute the already installed operating system. The question is about the installation part. I want to have that as easy and robust as possible, and of course, it should be an automated process.

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  • Exchange 2013 really slow outside of localhost

    - by ItsJustJP
    We've got a 12 core xeon, 24GB of ram 2012 server. We've recently migrated from exchange 2010 (which was on another server) to exchange 2013 which resides on our new 12 core server. Accessing the OWA on the exchange server is fine; it's very quick and responsive however accessing it via any other computer connect to the domain via a 1 gpbs connection and it'll take 10-15 seconds to load. Also running slow is public calenders that people in my place need to access, again taking 10-15 seconds to access and can sometimes cause outlook to not respond. Further to that we have phones that connect via the internet (of course) to the exchange so people can get work emails when they are out of the office. Guess what, this is also running slow. I've have search for many solutions and have tried changing outlook authentication methods but there is no change in speed. The old exchange 2010 server no longer exists but there was no problem before the migration. Has anyone got any suggestions? Thanks :) Must also mention that server 2012 that exchange 2013 is installed on is also the DC. Update: It would appear that any connection via https is slow. It took more than 15 mins for an outlook client to download 50MB of emails (outlook anywhere).

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  • Where can I legally obtain the 64bit version of Windows 8?

    - by Harsha K
    No, I am not looking to pirate. I bought a key through the Upgrade assistant (for just $15 due to the upgrade offer), but it downloaded an iso file that was between 2.3 and 2.5 GB. Which doesn't make sense to me, because the Evaluation version of Windows 8 x64 is closer to 3.4 GB in size. I assumed the Upgrade Assistant would be intelligent enough to realize that it is being run on a Windows 7 x64 machine and by extension, download the x64 code. Previously, I was able to legally download the ISOs (sans the keys, of course) from the Digital River host. I do not see an option to do that. I'm not interested in risking downloading a tampered ISO. I want to do it through Microsoft channels, but I just don't see how. As you may imagine, search terms such as "Windows 8 official download link" result in a plethora of obviously spyware infested piracy sites. If there's any non-exposing way for me to prove that I have legally purchased Windows and I'm genuinely looking for this answer, please let me know. For reference to what I am looking for it is similar to the answer given in this question for Windows 7: Where do I download Windows 7 (legally from Microsoft)?

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  • Windows 7 clean install becomes corrupt after reboot (repeated many fresh installs)

    - by pjotr_dolphin
    My laptop keeps crashing on boot after clean Windows 7 install. Ok, here is the story, and some fact. Computer: Samsung NP900X3C-A04HK (256GB SSD, 8GB RAM) OS to install: Windows 7 Ultimate SP1 (not from Samsung, own fresh Win) I purchased this laptop about a year ago, never booted it into the Windows Home that was installed on it, installed directly Ubuntu on the machine. Full disc encryption was the selected install, so of course it wiped the complete disc (including Samsung Recovery Partition). After some time, I felt like going back to Windows, as Windows 7 is actually quite nice. So I went to buy a fresh Windows 7Ultimate with SP1. Now to the tricky part. Windows installs perfectly, and after installing all Windows updates, drivers from Samsung, software I need, it is time for shutting it down and go to bed. Starting it up again, and it is not booting, these are the type of errors I have gotten so far (fresh installed it more then a dozen times now, and tried different suggestions from threads on the net). Windows failed to start... Status: 0xc000000f Info: The boot selection failed because a required device is inaccessible. File: /boot/bcd Status: 0xc000000f Info: an error occurred while attempting to read the boot configuration data. And some other errors, not all the same. Not memory of this. I have run different disc checks, and all says my SSD is in perfect shape. Note: Soft reboots from Windows menu works, never gets corrupted. But if I Shutdown and then start it up again, this is when it happens. Can someone help me not get back to Ubunut? What can be the cause, and how can it be fixed so I do not get there problems again?

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  • Computer makes odd noise. Replace almost every component. Computer still makes odd noise.

    - by ShimmerGeek
    My PC was getting pretty old, 5 years or so, and over the course of it's life I replaced the graphics card, HDD and a couple of sticks of RAM; but the PSU, processor, motherboard, fans etc. were all original. A few weeks ago, I started hearing an odd noise. I struggle to describe it, it sounded sortof like the 'click of death' you hear when a HDD may fail, but not quite... (And it was far less irregular) Also, I was sure I heard it once or twice a minute or two after I shut down the PC. This was going on very irregularly for a couple weeks. Some days I would hear no noise at all, others I would hear it often, maybe once every 30 seconds or so. I could find no common denominator - i.e. it did not happen more during gaming or any other intensive use. Anyway, I need my PC to sit some classes over the summer, so I put it in for them to run a HDD stress test and to replace a bunch of the components. I ended up replacing almost everything - the only elements I still have are my blu-ray drive and graphics card. They said when they started to run the HDD stress test it failed instantly (They started the test and it immediately said 'Test Complete' so they assumed it was at fault, and put a new HDD in since I was still under warranty with them.) I took it home a few hours ago, and I am still hearing the noise!!! Do you guys have any theories? I'm getting a little worried, I can't afford for my PC to suddenly fail during the next month - I have a lot of coursework to do. Any thoughts? Is it possible it could be the fan on the graphics card? I'm confused because it's so irregular. Any help would be much appreciated.

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  • Compare cells in two different spreadsheets and extract data from one an place it in the other if match found

    - by Fergie
    I need to find a way to compare two spreadsheets and if there is a match on specific cells, pull data from one sheet to another. Say the two spreadsheets contain a value that identifies a piece of equipment: spreadsheet 1 spreadsheet 2 Server Server Serial # 123abc 123abc 123-xx-456 There are of course many, many records/rows in each sheet. I need to look at the first cell in the server column of sheet 1 and then search a range of cells in the sever column of sheet 2 for a match. If there is a match, I need to pull the serial # value from the cell in the matching row an put it into the serial # cell of the matching row in sheet 1 (all of the "serial #" cells in sheet 1 are presently empty.) If that description explaination is too convoluted I can explain by answering any questions you may have. My deadline for this task is Noon tomorrow, 30 Aug 2012. Yes, I got the task today at noon.... I am not an Excel user and just get thrust into it on occassion... Any help would be a huge assist.

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  • oracle access on vmware fusion

    - by gaudi_br
    Hello, I'm running snow leopard and I'm doing some development that requires some network knowledge. I've installed vmware fusion 3.0 and I've set up a virtual machine with windows 2003 server. I need to mimic the exact configuration of another server in the network, so I really need to run the versions I'll be mentioning here. Besides, I set up two network configurations on the VM: one NAT config (so that I can have internet access) and one host-only config (because I need to use another server's mac adress and my local area network might have a problem with it) From the installation of windows 2003, I then installed oracle 10.2.0.1. During the installation I received a warning about the primary ip-address of the system being dhcp assigned, but I ignored it (maybe it was a mistake)... Now, from experience, unless the DHCP assigned address changes, I should be able to access the guest system's database from the host system, so I went to safari and tried to access the oracle em. As it turns out, because my computer is on a company network, the company's DNS doesn't know about the virtual machine, unless of course I switch to a bridged network config. However, I don't want to do that because I don't to mix up the domains. So I guess the question is, how can I define my own dns or router, or whatever it is that I need to define so that whenever I try the guest system's ip address form the host, it will use the vmnet1 or vmnet8 interface define by vmware and bypass the dns configuration of my local area network. I'd also like to know what to do incase I want to change ip addresses on the guest machine without having oracle go haywire (I've noticed a few folders on the structure which are specific for the very first IP Address)... Any help would be appreciated. Thanks in advance.

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  • How do I tunnel an HTTPS proxy through a virtual machine (VMWare)

    - by Kyle
    I have a personal setup at home using VMWare Workstation. I also have a set of Virtual Private Machines that run Squid, and therefore provide me HTTPS proxy tunnels. Using Proxifier, I can tunnel all traffic for given applications through these tunnels. However, I also have a few virtual machines for dev/staging/experimentation/etc. I generally just use NAT to provide Internet access to the machines, and if I need to use these proxies, I can just setup Proxifier (or a Linux equivalent) to pipe the traffic through them. No problem. But... I got to thinking: Wouldn't it be great if I could assign these proxy tunnels to a virtual machine, so that when I start up the VM, it has instant-on access through the tunnel and not my local connection? (EDIT: Of course, it would USE my local connection, but it would tunnel traffic through the proxy.) To be more clear: I want a solution that binds the proxy to a VM, so that when I start the VM, I don't have to use a proxy client to connect to the tunnel - I am already piping all traffic from that VM through that proxy. I did a bit of searching, and the closest thing I could find was this: How to route public static IP to a virtual machine on a vmware ESXi host? Which wasn't all that applicable. The proxies are protected by user/pass but do not filter by IP. Again, they are HTTPS proxies setup through Squid. Any ideas on how to make this happen? Thanks a ton.

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  • I can get in, but I can't get out

    - by robwilkerson
    Like most technical folks, I suppose, I'm my family's primary source of tech support. I'm a developer--not a sysadmin--by trade and tonight I bumped into something I've never seen before. I'm hoping someone here has. In order to better help my Mom, I have her set up on a home network behind a Linksys router (WRT54G). She's got a Mac, so I have her router set up to forward SSH requests to her laptop's internal IP. I also have her router running DDNS through DynDns. Tonight she called to tell me that she can't access the Internet. Assuming it was one of the many simple, stupid problems most of us encounter with parents, I logged into the router admin remotely and took a look around. Everything looked normal. Then I SSH'd into her machine to check out her IP, DNS, etc. settings. Everything still looked fine. Then I noticed something weird. When SSH'd into her machine, I can't ping her router. In other words, I seem to be able to access her computer through her router, but not access her router from her computer. A traceroute dies immediately as well. Any ideas what I might try next? I've bounced her computer and even unplugged her router (it was plugged back in, of course). Thanks.

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  • I can get in, but I can't get out

    - by robwilkerson
    Like most technical folks, I suppose, I'm my family's primary source of tech support. I'm a developer--not a sysadmin--by trade and tonight I bumped into something I've never seen before. I'm hoping someone here has. In order to better help my Mom, I have her set up on a home network behind a Linksys router (WRT54G). She's got a Mac, so I have her router set up to forward SSH requests to her laptop's internal IP. I also have her router running DDNS through DynDns. Tonight she called to tell me that she can't access the Internet. Assuming it was one of the many simple, stupid problems most of us encounter with parents, I logged into the router admin remotely and took a look around. Everything looked normal. Then I SSH'd into her machine to check out her IP, DNS, etc. settings. Everything still looked fine. Then I noticed something weird. When SSH'd into her machine, I can't ping her router. In other words, I seem to be able to access her computer through her router, but not access her router from her computer. A traceroute dies immediately as well. Any ideas what I might try next? I've bounced her computer and even unplugged her router (it was plugged back in, of course). Thanks.

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  • My Ubuntu 10.04 server kills all WAN bandwidth when it's attached to my LAN. Where do you begin troubleshooting?

    - by rrc7cz
    First I should say that my Linux knowledge is minimal; just enough to set up some servers (Apache, Tomcat, Couch, etc). I built a MiniITX server to host some simple sites, act as an SSH tunnel while I'm away, and act as a torrent server. It was not properly secured for a long time (iptables was empty, all ports open, no firewall) though my router did not have much port forwarding set up beyond HTTP, FTP, and SSH. A week or two ago my bandwidth at home dropped from around 27Mbps to 2Mbps and my upload went from 7Mbps to 0.06Mbps. When I unplug the server from the LAN, by bandwidth shoots back up. I threw up a restrictive iptables, removed most of the port forwarding, and checked my router logs to see if there were any open connections from the server (malware?) but there were none. What would you do? What are the first things you'd check? I can of course reinstall everything from scratch, but I'd like to find the root cause.

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  • What software will tell me if I've already downloaded a video? [closed]

    - by dave
    (I use Linux KNOPPIX (distro 7.0.2, ver 3.3.7) on hard drive.) I download videos of TV programs from the 60s and 70s (mainly from youtube). I copy the youtube URL then paste it into www.keepvid.com to download it (usually .mp4 format). Having now got dozens of such video files (and growing) on my hard drive, I'd like to organise them. WHAT I'D LIKE TO DO IS: Say I find a new vid (of a TV prog) on youtube (or another site), and I'm about to download it. It's possible that I've WATCHED IT BEFORE but have forgotten. So is there software out there that I can run which will do the following: Check for me if I've ALREADY WATCHED the vid that I'm about to download. At the moment, once I've watched a vid on my hard drive, I move the file to another directory called "Watched". But this of course doesn't alert me in the immediate way that I want. . It would crudely suffice, if the software told me AFTER I've downloaded the vid, if I've ALREADY WATCHED it (ie if it's already in my "Watched" directory, or perhaps in a "watched" list). I sometimes alter the filename of the original video file on hard drive, so this might spoil a comparison. If the software alerts me to the fact that I've already watched the vid (preferably BEFORE I download it), then this will allow me to confidently download only new vids that I haven't watched before, and save me duplicating my effort. I'd be most grateful if anyone can suggest such a piece of software, or an alternative solution. I'll be honest, I avoid software that infringes your privacy and control - you know, software that automatically does things behind your back, like upgrades itself over the internet, puts things on your hard drive that you didn't ask for, or sends information from your hard drive to websites.

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  • cannot connect to my nginx server from remote machine

    - by margincall
    I thought that it's iptables problem.. but it seems not. I really have no idea about this situation. I'm getting a server hosting(CentOS). I installed Nginx + Django and nginx uses 8080 port. A domain is connected to the server. When I executed "wget [domain]:8080/[app name]/" in the server, it worked. Of course, "wget 127.0.0.1:8080/[app name]/" has no problem. (wget [server ip]:8080/[app name]/, either) However, from other computers, connecting was failed. (message says, no route) I checked my firewall setting. I excuted these commands. iptables -I INPUT -p tcp --dport 8080 -j ACCEPT iptables -I OUTPUT -p tcp --sport 8080 -j ACCEPT iptables -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT /etc/init.d/iptables restart I don't really understand all options of commands and I think there were useless commands, but I just tried all googled iptables settings. But still I cannot connect to my server. What should I check, first? I don't know this is important, but add to this post. On 80 port, an apache server is running. It works fine, I can connect to apache from other computers. There is DB connecting issue, (PHP to MySQL) but I think that it is just PHP coding bug. please excuse my low-level English. I'm not native English speaker.. but I tried to explane well as far as possible. Thank you for reading this question.

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  • Linux Server partitioning

    - by user1717735
    There's a lot of infos about this out there, but there's also a lot of contradictory infos… That's why i need some advices about it. So far, on the servers i had home for test (or even "home production") purposes i didn't really care about partitioning and i configured all in / + a swap partition, over RAID 0. Nevertheless, this pattern can't apply to production servers. I have found a good starting point here, but also it depends on what the servers will be used for… So basically, i have a server on which there will be apache, php, mysql. It will have to handle file uploads (up to 2GB) and has 2*2TB hard drive. I plan to set : / 100GB, /var 1000GB (apache files and mysql files will be here), /tmp 800GB (handles the php tmp file) /home 96GB swap 4GB All of this if of course over RAID 1. But actually, it's not a big deal if I lose data being uploaded, so would it be interesting mounting /tmp over raid 0 while maintaining the rest over raid 1? Sounds complicated…

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  • BYOD (accessing files) on a domain without joining?

    - by Philip White
    I run a Samba 4 instance at a small private school. This makes a regular Linux server appear as a directory controller. There are two relevant benefits to this: I have a Samba share for people's documents, and I use the Redirected Folders feature to allow any employee to sit down at any PC, log in with their domain credentials, and their My Documents points to network storage. Everyone has a mapped drive (using Group Policy Preferences) to a share specific to their account type. Students can access one share (one share for all students), teachers have another, and office staff have another. However, I would like to allow BYOD (Bring Your Own Device). Some employees are already asking for it with their personal laptops, and I know eventually most everyone will want to. Is there any way to replicate the two features above without having to join PCs to the domain? Joining personal PCs is impractical if only because only professional editions of Windows support this. Ideally, any operating system (including mobile) could access the relevant shares, but of course Windows is key. Offline caching is optional. (I could set up OpenVPN for teachers who want to access their files from home.) The problem with simply giving SSH access to the relevant shares is primarily that Samba 4 relies on ext4 ACLs and ext4 extended attributes to maintain NTFS permissions. Writing files directly to the Linux server would bypass this and would (probably) not be interoperable with Samba4. Right now I am completely flexible. I am even fine with scrapping the whole domain and using some other software for the two features above. How can I allow school employees and students freedom to securely share files without requiring everyone to have specific editions of Windows?

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  • Storage model for various user setting and attributes in database?

    - by dvd
    I'm currently trying to upgrade a user management system for one web application. This web application is used to provide remote access to various networking equipment for educational purposes. All equipment is assigned to various pods, which users can book for periods of time. The current system is very simple - just 2 user types: administrators and students. All their security and other attributes are mostly hardcoded. I want to change this to something like the following model: user <-- (1..n)profile <--- (1..n) attributes. I.e. user can be assigned several profiles and each profile can have multiple attributes. At runtime all profiles and attributes are merged into single active profile. Some examples of attributes i'm planning to implement: EXPIRATION_DATE - single value, value type: date, specifies when user account will expire; ACCESS_POD - single value, value type: ref to object of Pod class, specifies which pod the user is allowed to book, user profile can have multiple such attributes with different values; TIME_QUOTA - single value, value type: integer, specifies maximum length of time for which student can reserve equipment. CREDIT_CHARGING - multi valued, specifies how much credits will be assigned to user over period of time. (Reservation of devices will cost credits, which will regenerate over time); Security permissions and user preferences can end up as profile or user attributes too: i.e CAN_CREATE_USERS, CAN_POST_NEWS, CAN_EDIT_DEVICES, FONT_SIZE, etc.. This way i could have, for example: students of course A will have profiles STUDENT (with basic attributes) and PROFILE A (wich grants acces to pod A). Students of course B will have profiles: STUDENT, PROFILE B(wich grants to pod B and have increased time quotas). I'm using Spring and Hibernate frameworks for this application and MySQL for database. For this web application i would like to stay within boundaries of these tools. The problem is, that i can't figure out how to best represent all these attributes in database. I also want to create some kind of unified way of retrieveing these attributes and their values. Here is the model i've come up with. Base classes. public abstract class Attribute{ private Long id; Attribute() {} abstract public String getName(); public Long getId() {return id; } void setId(Long id) {this.id = id;} } public abstract class SimpleAttribute extends Attribute{ public abstract Serializable getValue(); abstract void setValue(Serializable s); @Override public boolean equals(Object obj) { ... } @Override public int hashCode() { ... } } Simple attributes can have only one value of any type (including object and enum). Here are more specific attributes: public abstract class IntAttribute extends SimpleAttribute { private Integer value; public Integer getValue() { return value; } void setValue(Integer value) { this.value = value;} void setValue(Serializable s) { setValue((Integer)s); } } public class MaxOrdersAttribute extends IntAttribute { public String getName() { return "Maximum outstanding orders"; } } public final class CreditRateAttribute extends IntAttribute { public String getName() { return "Credit Regeneration Rate"; } } All attributes stored stored using Hibenate variant "table per class hierarchy". Mapping: <class name="ru.mirea.rea.model.abac.Attribute" table="ATTRIBUTES" abstract="true" > <id name="id" column="id"> <generator class="increment" /> </id> <discriminator column="attributeType" type="string"/> <subclass name="ru.mirea.rea.model.abac.SimpleAttribute" abstract="true"> <subclass name="ru.mirea.rea.model.abac.IntAttribute" abstract="true" > <property name="value" column="intVal" type="integer"/> <subclass name="ru.mirea.rea.model.abac.CreditRateAttribute" discriminator-value="CreditRate" /> <subclass name="ru.mirea.rea.model.abac.MaxOrdersAttribute" discriminator-value="MaxOrders" /> </subclass> <subclass name="ru.mirea.rea.model.abac.DateAttribute" abstract="true" > <property name="value" column="dateVal" type="timestamp"/> <subclass name="ru.mirea.rea.model.abac.ExpirationDateAttribute" discriminator-value="ExpirationDate" /> </subclass> <subclass name="ru.mirea.rea.model.abac.PodAttribute" abstract="true" > <many-to-one name="value" column="podVal" class="ru.mirea.rea.model.pods.Pod"/> <subclass name="ru.mirea.rea.model.abac.PodAccessAttribute" discriminator-value="PodAccess" lazy="false"/> </subclass> <subclass name="ru.mirea.rea.model.abac.SecurityPermissionAttribute" discriminator-value="SecurityPermission" lazy="false"> <property name="value" column="spVal" type="ru.mirea.rea.db.hibernate.customTypes.SecurityPermissionType"/> </subclass> </subclass> </class> SecurityPermissionAttribute uses enumeration of various permissions as it's value. Several types of attributes imlement GrantedAuthority interface and can be used with Spring Security for authentication and authorization. Attributes can be created like this: public final class AttributeManager { public <T extends SimpleAttribute> T createSimpleAttribute(Class<T> c, Serializable value) { Session session = HibernateUtil.getCurrentSession(); T att = null; ... att = c.newInstance(); att.setValue(value); session.save(att); session.flush(); ... return att; } public <T extends SimpleAttribute> List<T> findSimpleAttributes(Class<T> c) { List<T> result = new ArrayList<T>(); Session session = HibernateUtil.getCurrentSession(); List<T> temp = session.createCriteria(c).list(); result.addAll(temp); return result; } } And retrieved through User Profiles to which they are assigned. I do not expect that there would be very large amount of rows in the ATTRIBUTES table, but are there any serious drawbacks of such design?

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  • Wired component null in seam EntityHome action

    - by rangalo
    I have a custom EntityHome class. I wire the dependent entity in the wire method, but when I call the action (persist) the wired component is always null. What could be the reason, similar code generated by seam gen is apparently working. Here is the entity class. I have overrden persist method to log the value of the wired element. @Name("roundHome") @Scope(ScopeType.CONVERSATION) public class RoundHome extends EntityHome<Round>{ @In(required = false) private Golfer currentGolfer; @In(create = true) private TeeSetHome teeSetHome; @Override public String persist() { logger.info("Persist called"); if (null != getInstance().getTeeSet() ) { logger.info("teeSet not null in persist"); } else { logger.info("teeSet null in persist"); // wire(); } String retVal = super.persist(); //To change body of overridden methods use File | Settings | File Templates. return retVal; } @Logger private Log logger; public void wire() { logger.info("wire called"); TeeSet teeSet = teeSetHome.getDefinedInstance(); if (null != teeSet) { getInstance().setTeeSet(teeSet); logger.info("Successfully wired the teeSet instance with color: " + teeSet.getColor()); } } public boolean isWired() { logger.info("is wired called"); if(null == getInstance().getTeeSet()) { logger.info("wired teeSet instance is null, the button will be disabled !"); return false; } else { logger.info("wired teeSet instance is NOT null, the button will be enabled !"); logger.info("teeSet color: "+getInstance().getTeeSet().getColor()); return true; } } @RequestParameter public void setRoundId(Long id) { super.setId(id); } @Override protected Round createInstance() { Round round = super.createInstance(); round.setGolfer(currentGolfer); round.setDate(new java.sql.Date(System.currentTimeMillis())); return round; } } Here the xhtml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://jboss.com/products/seam/taglib" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html" xmlns:a="http://richfaces.org/a4j" xmlns:rich="http://richfaces.org/rich" template="layout/template.xhtml"> <ui:define name="body"> <h:form id="roundform"> <rich:panel> <f:facet name="header>"> #{roundHome.managed ? 'Edit' : 'Add' } Round </f:facet> <s:decorate id="dateField" template="layout/edit.xhtml"> <ui:define name="label">Date:</ui:define> <rich:calendar id="date" datePattern="dd/MM/yyyy" value="#{round.date}"/> </s:decorate> <s:decorate id="notesField" template="layout/edit.xhtml"> <ui:define name="label">Notes:</ui:define> <h:inputTextarea id="notes" cols="80" rows="3" value="#{round.notes}" /> </s:decorate> <s:decorate id="totalScoreField" template="layout/edit.xhtml"> <ui:define name="label">Total Score:</ui:define> <h:inputText id="totalScore" value="#{round.totalScore}" /> </s:decorate> <s:decorate id="weatherField" template="layout/edit.xhtml"> <ui:define name="label">Weather:</ui:define> <h:selectOneMenu id="weather" value="#{round.weather}"> <s:selectItems var="_weather" value="#{weatherCategories}" label="#{_weather.label}" noSelectionLabel=" Select " /> <s:convertEnum/> </h:selectOneMenu> </s:decorate> <div style="clear: both;"> <span class="required">*</span> required fields </div> </rich:panel> <div class="actionButtons"> <h:commandButton id="save" value="Save" action="#{roundHome.persist}" rendered="#{!roundHome.managed}" /> <!-- disabled="#{!roundHome.wired}" /> --> <h:commandButton id="update" value="Update" action="#{roundHome.update}" rendered="#{roundHome.managed}" /> <h:commandButton id="delete" value="Delete" action="#{roundHome.remove}" rendered="#{roundHome.managed}" /> <s:button id="discard" value="Discard changes" propagation="end" view="/Round.xhtml" rendered="#{roundHome.managed}" /> <s:button id="cancel" value="Cancel" propagation="end" view="/#{empty roundFrom ? 'RoundList' : roundFrom}.xhtml" rendered="#{!roundHome.managed}" /> </div> <rich:tabPanel> <rich:tab label="Tee Set"> <div class="association"> <h:outputText value="Tee set not selected" rendered="#{round.teeSet == null}" /> <rich:dataTable var="_teeSet" value="#{round.teeSet}" rendered="#{round.teeSet != null}"> <h:column> <f:facet name="header">Course</f:facet>#{_teeSet.course.name} </h:column> <h:column> <f:facet name="header">Color</f:facet>#{_teeSet.color} </h:column> <h:column> <f:facet name="header">Position</f:facet>#{_teeSet.pos} </h:column> </rich:dataTable> </div> </rich:tab> </rich:tabPanel> </h:form> </ui:define> </ui:composition>

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  • Dealing with external processes

    - by Jesse Aldridge
    I've been working on a gui app that needs to manage external processes. Working with external processes leads to a lot of issues that can make a programmer's life difficult. I feel like maintenence on this app is taking an unacceptably long time. I've been trying to list the things that make working with external processes difficult so that I can come up with ways of mitigating the pain. This kind of turned into a rant which I thought I'd post here in order to get some feedback and to provide some guidance to anybody thinking about sailing into these very murky waters. Here's what I've got so far: Output from the child can get mixed up with output from the parent. This can make both outputs misleading and hard to read. It can be hard to tell what came from where. It becomes harder to figure out what's going on when things are asynchronous. Here's a contrived example: import textwrap, os, time from subprocess import Popen test_path = 'test_file.py' with open(test_path, 'w') as file: file.write(textwrap.dedent(''' import time for i in range(3): print 'Hello %i' % i time.sleep(1)''')) proc = Popen('python -B "%s"' % test_path) for i in range(3): print 'Hello %i' % i time.sleep(1) os.remove(test_path) I guess I could have the child process write its output to a file. But it can be annoying to have to open up a file every time I want to see the result of a print statement. If I have code for the child process I could add a label, something like print 'child: Hello %i', but it can be annoying to do that for every print. And it adds some noise to the output. And of course I can't do it if I don't have access to the code. I could manually manage the process output. But then you open up a huge can of worms with threads and polling and stuff like that. A simple solution is to treat processes like synchronous functions, that is, no further code executes until the process completes. In other words, make the process block. But that doesn't work if you're building a gui app. Which brings me to the next problem... Blocking processes cause the gui to become unresponsive. import textwrap, sys, os from subprocess import Popen from PyQt4.QtGui import * from PyQt4.QtCore import * test_path = 'test_file.py' with open(test_path, 'w') as file: file.write(textwrap.dedent(''' import time for i in range(3): print 'Hello %i' % i time.sleep(1)''')) app = QApplication(sys.argv) button = QPushButton('Launch process') def launch_proc(): # Can't move the window until process completes proc = Popen('python -B "%s"' % test_path) proc.communicate() button.connect(button, SIGNAL('clicked()'), launch_proc) button.show() app.exec_() os.remove(test_path) Qt provides a process wrapper of its own called QProcess which can help with this. You can connect functions to signals to capture output relatively easily. This is what I'm currently using. But I'm finding that all these signals behave suspiciously like goto statements and can lead to spaghetti code. I think I want to get sort-of blocking behavior by having the 'finished' signal from QProcess call a function containing all the code that comes after the process call. I think that should work but I'm still a bit fuzzy on the details... Stack traces get interrupted when you go from the child process back to the parent process. If a normal function screws up, you get a nice complete stack trace with filenames and line numbers. If a subprocess screws up, you'll be lucky if you get any output at all. You end up having to do a lot more detective work everytime something goes wrong. Speaking of which, output has a way of disappearing when dealing external processes. Like if you run something via the windows 'cmd' command, the console will pop up, execute the code, and then disappear before you have a chance to see the output. You have to pass the /k flag to make it stick around. Similar issues seem to crop up all the time. I suppose both problems 3 and 4 have the same root cause: no exception handling. Exception handling is meant to be used with functions, it doesn't work with processes. Maybe there's some way to get something like exception handling for processes? I guess that's what stderr is for? But dealing with two different streams can be annoying in itself. Maybe I should look into this more... Processes can hang and stick around in the background without you realizing it. So you end up yelling at your computer cuz it's going so slow until you finally bring up your task manager and see 30 instances of the same process hanging out in the background. Also, hanging background processes can interefere with other instances of the process in various fun ways, such as causing permissions errors by holding a handle to a file or someting like that. It seems like an easy solution to this would be to have the parent process kill the child process on exit if the child process didn't close itself. But if the parent process crashes, cleanup code might not get called and the child can be left hanging. Also, if the parent waits for the child to complete, and the child is in an infinite loop or something, you can end up with two hanging processes. This problem can tie in to problem 2 for extra fun, causing your gui to stop responding entirely and force you to kill everything with the task manager. F***ing quotes Parameters often need to be passed to processes. This is a headache in itself. Especially if you're dealing with file paths. Say... 'C:/My Documents/whatever/'. If you don't have quotes, the string will often be split at the space and interpreted as two arguments. If you need nested quotes you can use ' and ". But if you need to use more than two layers of quotes, you have to do some nasty escaping, for example: "cmd /k 'python \'path 1\' \'path 2\''". A good solution to this problem is passing parameters as a list rather than as a single string. Subprocess allows you to do this. Can't easily return data from a subprocess. You can use stdout of course. But what if you want to throw a print in there for debugging purposes? That's gonna screw up the parent if it's expecting output formatted a certain way. In functions you can print one string and return another and everything works just fine. Obscure command-line flags and a crappy terminal based help system. These are problems I often run into when using os level apps. Like the /k flag I mentioned, for holding a cmd window open, who's idea was that? Unix apps don't tend to be much friendlier in this regard. Hopefully you can use google or StackOverflow to find the answer you need. But if not, you've got a lot of boring reading and frusterating trial and error to do. External factors. This one's kind of fuzzy. But when you leave the relatively sheltered harbor of your own scripts to deal with external processes you find yourself having to deal with the "outside world" to a much greater extent. And that's a scary place. All sorts of things can go wrong. Just to give a random example: the cwd in which a process is run can modify it's behavior. There are probably other issues, but those are the ones I've written down so far. Any other snags you'd like to add? Any suggestions for dealing with these problems?

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  • Authoritative sources about Database vs. Flatfile decision

    - by FastAl
    <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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  • How do I prove I should put a table of values in source code instead of a database table?

    - by FastAl
    <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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  • Using the West Wind Web Toolkit to set up AJAX and REST Services

    - by Rick Strahl
    I frequently get questions about which option to use for creating AJAX and REST backends for ASP.NET applications. There are many solutions out there to do this actually, but when I have a choice - not surprisingly - I fall back to my own tools in the West Wind West Wind Web Toolkit. I've talked a bunch about the 'in-the-box' solutions in the past so for a change in this post I'll talk about the tools that I use in my own and customer applications to handle AJAX and REST based access to service resources using the West Wind West Wind Web Toolkit. Let me preface this by saying that I like things to be easy. Yes flexible is very important as well but not at the expense of over-complexity. The goal I've had with my tools is make it drop dead easy, with good performance while providing the core features that I'm after, which are: Easy AJAX/JSON Callbacks Ability to return any kind of non JSON content (string, stream, byte[], images) Ability to work with both XML and JSON interchangeably for input/output Access endpoints via POST data, RPC JSON calls, GET QueryString values or Routing interface Easy to use generic JavaScript client to make RPC calls (same syntax, just what you need) Ability to create clean URLS with Routing Ability to use standard ASP.NET HTTP Stack for HTTP semantics It's all about options! In this post I'll demonstrate most of these features (except XML) in a few simple and short samples which you can download. So let's take a look and see how you can build an AJAX callback solution with the West Wind Web Toolkit. Installing the Toolkit Assemblies The easiest and leanest way of using the Toolkit in your Web project is to grab it via NuGet: West Wind Web and AJAX Utilities (Westwind.Web) and drop it into the project by right clicking in your Project and choosing Manage NuGet Packages from anywhere in the Project.   When done you end up with your project looking like this: What just happened? Nuget added two assemblies - Westwind.Web and Westwind.Utilities and the client ww.jquery.js library. It also added a couple of references into web.config: The default namespaces so they can be accessed in pages/views and a ScriptCompressionModule that the toolkit optionally uses to compress script resources served from within the assembly (namely ww.jquery.js and optionally jquery.js). Creating a new Service The West Wind Web Toolkit supports several ways of creating and accessing AJAX services, but for this post I'll stick to the lower level approach that works from any plain HTML page or of course MVC, WebForms, WebPages. There's also a WebForms specific control that makes this even easier but I'll leave that for another post. So, to create a new standalone AJAX/REST service we can create a new HttpHandler in the new project either as a pure class based handler or as a generic .ASHX handler. Both work equally well, but generic handlers don't require any web.config configuration so I'll use that here. In the root of the project add a Generic Handler. I'm going to call this one StockService.ashx. Once the handler has been created, edit the code and remove all of the handler body code. Then change the base class to CallbackHandler and add methods that have a [CallbackMethod] attribute. Here's the modified base handler implementation now looks like with an added HelloWorld method: using System; using Westwind.Web; namespace WestWindWebAjax { /// <summary> /// Handler implements CallbackHandler to provide REST/AJAX services /// </summary> public class SampleService : CallbackHandler { [CallbackMethod] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } } } Notice that the class inherits from CallbackHandler and that the HelloWorld service method is marked up with [CallbackMethod]. We're done here. Services Urlbased Syntax Once you compile, the 'service' is live can respond to requests. All CallbackHandlers support input in GET and POST formats, and can return results as JSON or XML. To check our fancy HelloWorld method we can now access the service like this: http://localhost/WestWindWebAjax/StockService.ashx?Method=HelloWorld&name=Rick which produces a default JSON response - in this case a string (wrapped in quotes as it's JSON): (note by default JSON will be downloaded by most browsers not displayed - various options are available to view JSON right in the browser) If I want to return the same data as XML I can tack on a &format=xml at the end of the querystring which produces: <string>Hello Rick. Time is: 11/1/2011 12:11:13 PM</string> Cleaner URLs with Routing Syntax If you want cleaner URLs for each operation you can also configure custom routes on a per URL basis similar to the way that WCF REST does. To do this you need to add a new RouteHandler to your application's startup code in global.asax.cs one for each CallbackHandler based service you create: protected void Application_Start(object sender, EventArgs e) { CallbackHandlerRouteHandler.RegisterRoutes<StockService>(RouteTable.Routes); } With this code in place you can now add RouteUrl properties to any of your service methods. For the HelloWorld method that doesn't make a ton of sense but here is what a routed clean URL might look like in definition: [CallbackMethod(RouteUrl="stocks/HelloWorld/{name}")] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } The same URL I previously used now becomes a bit shorter and more readable with: http://localhost/WestWindWebAjax/HelloWorld/Rick It's an easy way to create cleaner URLs and still get the same functionality. Calling the Service with $.getJSON() Since the result produced is JSON you can now easily consume this data using jQuery's getJSON method. First we need a couple of scripts - jquery.js and ww.jquery.js in the page: <!DOCTYPE html> <html> <head> <link href="Css/Westwind.css" rel="stylesheet" type="text/css" /> <script src="scripts/jquery.min.js" type="text/javascript"></script> <script src="scripts/ww.jquery.min.js" type="text/javascript"></script> </head> <body> Next let's add a small HelloWorld example form (what else) that has a single textbox to type a name, a button and a div tag to receive the result: <fieldset> <legend>Hello World</legend> Please enter a name: <input type="text" name="txtHello" id="txtHello" value="" /> <input type="button" id="btnSayHello" value="Say Hello (POST)" /> <input type="button" id="btnSayHelloGet" value="Say Hello (GET)" /> <div id="divHelloMessage" class="errordisplay" style="display:none;width: 450px;" > </div> </fieldset> Then to call the HelloWorld method a little jQuery is used to hook the document startup and the button click followed by the $.getJSON call to retrieve the data from the server. <script type="text/javascript"> $(document).ready(function () { $("#btnSayHelloGet").click(function () { $.getJSON("SampleService.ashx", { Method: "HelloWorld", name: $("#txtHello").val() }, function (result) { $("#divHelloMessage") .text(result) .fadeIn(1000); }); });</script> .getJSON() expects a full URL to the endpoint of our service, which is the ASHX file. We can either provide a full URL (SampleService.ashx?Method=HelloWorld&name=Rick) or we can just provide the base URL and an object that encodes the query string parameters for us using an object map that has a property that matches each parameter for the server method. We can also use the clean URL routing syntax, but using the object parameter encoding actually is safer as the parameters will get properly encoded by jQuery. The result returned is whatever the result on the server method is - in this case a string. The string is applied to the divHelloMessage element and we're done. Obviously this is a trivial example, but it demonstrates the basics of getting a JSON response back to the browser. AJAX Post Syntax - using ajaxCallMethod() The previous example allows you basic control over the data that you send to the server via querystring parameters. This works OK for simple values like short strings, numbers and boolean values, but doesn't really work if you need to pass something more complex like an object or an array back up to the server. To handle traditional RPC type messaging where the idea is to map server side functions and results to a client side invokation, POST operations can be used. The easiest way to use this functionality is to use ww.jquery.js and the ajaxCallMethod() function. ww.jquery wraps jQuery's AJAX functions and knows implicitly how to call a CallbackServer method with parameters and parse the result. Let's look at another simple example that posts a simple value but returns something more interesting. Let's start with the service method: [CallbackMethod(RouteUrl="stocks/{symbol}")] public StockQuote GetStockQuote(string symbol) { Response.Cache.SetExpires(DateTime.UtcNow.Add(new TimeSpan(0, 2, 0))); StockServer server = new StockServer(); var quote = server.GetStockQuote(symbol); if (quote == null) throw new ApplicationException("Invalid Symbol passed."); return quote; } This sample utilizes a small StockServer helper class (included in the sample) that downloads a stock quote from Yahoo's financial site via plain HTTP GET requests and formats it into a StockQuote object. Lets create a small HTML block that lets us query for the quote and display it: <fieldset> <legend>Single Stock Quote</legend> Please enter a stock symbol: <input type="text" name="txtSymbol" id="txtSymbol" value="msft" /> <input type="button" id="btnStockQuote" value="Get Quote" /> <div id="divStockDisplay" class="errordisplay" style="display:none; width: 450px;"> <div class="label-left">Company:</div> <div id="stockCompany"></div> <div class="label-left">Last Price:</div> <div id="stockLastPrice"></div> <div class="label-left">Quote Time:</div> <div id="stockQuoteTime"></div> </div> </fieldset> The final result looks something like this:   Let's hook up the button handler to fire the request and fill in the data as shown: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").show().fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, HH:mm EST")); }, onPageError); }); So we point at SampleService.ashx and the GetStockQuote method, passing a single parameter of the input symbol value. Then there are two handlers for success and failure callbacks.  The success handler is the interesting part - it receives the stock quote as a result and assigns its values to various 'holes' in the stock display elements. The data that comes back over the wire is JSON and it looks like this: { "Symbol":"MSFT", "Company":"Microsoft Corpora", "OpenPrice":26.11, "LastPrice":26.01, "NetChange":0.02, "LastQuoteTime":"2011-11-03T02:00:00Z", "LastQuoteTimeString":"Nov. 11, 2011 4:20pm" } which is an object representation of the data. JavaScript can evaluate this JSON string back into an object easily and that's the reslut that gets passed to the success function. The quote data is then applied to existing page content by manually selecting items and applying them. There are other ways to do this more elegantly like using templates, but here we're only interested in seeing how the data is returned. The data in the object is typed - LastPrice is a number and QuoteTime is a date. Note about the date value: JavaScript doesn't have a date literal although the JSON embedded ISO string format used above  ("2011-11-03T02:00:00Z") is becoming fairly standard for JSON serializers. However, JSON parsers don't deserialize dates by default and return them by string. This is why the StockQuote actually returns a string value of LastQuoteTimeString for the same date. ajaxMethodCallback always converts dates properly into 'real' dates and the example above uses the real date value along with a .formatDate() data extension (also in ww.jquery.js) to display the raw date properly. Errors and Exceptions So what happens if your code fails? For example if I pass an invalid stock symbol to the GetStockQuote() method you notice that the code does this: if (quote == null) throw new ApplicationException("Invalid Symbol passed."); CallbackHandler automatically pushes the exception message back to the client so it's easy to pick up the error message. Regardless of what kind of error occurs: Server side, client side, protocol errors - any error will fire the failure handler with an error object parameter. The error is returned to the client via a JSON response in the error callback. In the previous examples I called onPageError which is a generic routine in ww.jquery that displays a status message on the bottom of the screen. But of course you can also take over the error handling yourself: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); }, function (error, xhr) { $("#divErrorDisplay").text(error.message).fadeIn(1000); }); }); The error object has a isCallbackError, message and  stackTrace properties, the latter of which is only populated when running in Debug mode, and this object is returned for all errors: Client side, transport and server side errors. Regardless of which type of error you get the same object passed (as well as the XHR instance optionally) which makes for a consistent error retrieval mechanism. Specifying HttpVerbs You can also specify HTTP Verbs that are allowed using the AllowedHttpVerbs option on the CallbackMethod attribute: [CallbackMethod(AllowedHttpVerbs=HttpVerbs.GET | HttpVerbs.POST)] public string HelloWorld(string name) { … } If you're building REST style API's this might be useful to force certain request semantics onto the client calling. For the above if call with a non-allowed HttpVerb the request returns a 405 error response along with a JSON (or XML) error object result. The default behavior is to allow all verbs access (HttpVerbs.All). Passing in object Parameters Up to now the parameters I passed were very simple. But what if you need to send something more complex like an object or an array? Let's look at another example now that passes an object from the client to the server. Keeping with the Stock theme here lets add a method called BuyOrder that lets us buy some shares for a stock. Consider the following service method that receives an StockBuyOrder object as a parameter: [CallbackMethod] public string BuyStock(StockBuyOrder buyOrder) { var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } public class StockBuyOrder { public string Symbol { get; set; } public int Quantity { get; set; } public DateTime BuyOn { get; set; } public StockBuyOrder() { BuyOn = DateTime.Now; } } This is a contrived do-nothing example that simply echoes back what was passed in, but it demonstrates how you can pass complex data to a callback method. On the client side we now have a very simple form that captures the three values on a form: <fieldset> <legend>Post a Stock Buy Order</legend> Enter a symbol: <input type="text" name="txtBuySymbol" id="txtBuySymbol" value="GLD" />&nbsp;&nbsp; Qty: <input type="text" name="txtBuyQty" id="txtBuyQty" value="10" style="width: 50px" />&nbsp;&nbsp; Buy on: <input type="text" name="txtBuyOn" id="txtBuyOn" value="<%= DateTime.Now.ToString("d") %>" style="width: 70px;" /> <input type="button" id="btnBuyStock" value="Buy Stock" /> <div id="divStockBuyMessage" class="errordisplay" style="display:none"></div> </fieldset> The completed form and demo then looks something like this:   The client side code that picks up the input values and assigns them to object properties and sends the AJAX request looks like this: $("#btnBuyStock").click(function () { // create an object map that matches StockBuyOrder signature var buyOrder = { Symbol: $("#txtBuySymbol").val(), Quantity: $("#txtBuyQty").val() * 1, // number Entered: new Date() } ajaxCallMethod("SampleService.ashx", "BuyStock", [buyOrder], function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError); }); The code creates an object and attaches the properties that match the server side object passed to the BuyStock method. Each property that you want to update needs to be included and the type must match (ie. string, number, date in this case). Any missing properties will not be set but also not cause any errors. Pass POST data instead of Objects In the last example I collected a bunch of values from form variables and stuffed them into object variables in JavaScript code. While that works, often times this isn't really helping - I end up converting my types on the client and then doing another conversion on the server. If lots of input controls are on a page and you just want to pick up the values on the server via plain POST variables - that can be done too - and it makes sense especially if you're creating and filling the client side object only to push data to the server. Let's add another method to the server that once again lets us buy a stock. But this time let's not accept a parameter but rather send POST data to the server. Here's the server method receiving POST data: [CallbackMethod] public string BuyStockPost() { StockBuyOrder buyOrder = new StockBuyOrder(); buyOrder.Symbol = Request.Form["txtBuySymbol"]; ; int qty; int.TryParse(Request.Form["txtBuyQuantity"], out qty); buyOrder.Quantity = qty; DateTime time; DateTime.TryParse(Request.Form["txtBuyBuyOn"], out time); buyOrder.BuyOn = time; // Or easier way yet //FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } Clearly we've made this server method take more code than it did with the object parameter. We've basically moved the parameter assignment logic from the client to the server. As a result the client code to call this method is now a bit shorter since there's no client side shuffling of values from the controls to an object. $("#btnBuyStockPost").click(function () { ajaxCallMethod("SampleService.ashx", "BuyStockPost", [], // Note: No parameters - function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError, // Force all page Form Variables to be posted { postbackMode: "Post" }); }); The client simply calls the BuyStockQuote method and pushes all the form variables from the page up to the server which parses them instead. The feature that makes this work is one of the options you can pass to the ajaxCallMethod() function: { postbackMode: "Post" }); which directs the function to include form variable POST data when making the service call. Other options include PostNoViewState (for WebForms to strip out WebForms crap vars), PostParametersOnly (default), None. If you pass parameters those are always posted to the server except when None is set. The above code can be simplified a bit by using the FormVariableBinder helper, which can unbind form variables directly into an object: FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); which replaces the manual Request.Form[] reading code. It receives the object to unbind into, a string of properties to skip, and an optional prefix which is stripped off form variables to match property names. The component is similar to the MVC model binder but it's independent of MVC. Returning non-JSON Data CallbackHandler also supports returning non-JSON/XML data via special return types. You can return raw non-JSON encoded strings like this: [CallbackMethod(ReturnAsRawString=true,ContentType="text/plain")] public string HelloWorldNoJSON(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } Calling this method results in just a plain string - no JSON encoding with quotes around the result. This can be useful if your server handling code needs to return a string or HTML result that doesn't fit well for a page or other UI component. Any string output can be returned. You can also return binary data. Stream, byte[] and Bitmap/Image results are automatically streamed back to the client. Notice that you should set the ContentType of the request either on the CallbackMethod attribute or using Response.ContentType. This ensures the Web Server knows how to display your binary response. Using a stream response makes it possible to return any of data. Streamed data can be pretty handy to return bitmap data from a method. The following is a method that returns a stock history graph for a particular stock over a provided number of years: [CallbackMethod(ContentType="image/png",RouteUrl="stocks/history/graph/{symbol}/{years}")] public Stream GetStockHistoryGraph(string symbol, int years = 2,int width = 500, int height=350) { if (width == 0) width = 500; if (height == 0) height = 350; StockServer server = new StockServer(); return server.GetStockHistoryGraph(symbol,"Stock History for " + symbol,width,height,years); } I can now hook this up into the JavaScript code when I get a stock quote. At the end of the process I can assign the URL to the service that returns the image into the src property and so force the image to display. Here's the changed code: $("#btnStockQuote").click(function () { var symbol = $("#txtSymbol").val(); ajaxCallMethod("SampleService.ashx", "GetStockQuote", [symbol], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); // display a stock chart $("#imgStockHistory").attr("src", "stocks/history/graph/" + symbol + "/2"); },onPageError); }); The resulting output then looks like this: The charting code uses the new ASP.NET 4.0 Chart components via code to display a bar chart of the 2 year stock data as part of the StockServer class which you can find in the sample download. The ability to return arbitrary data from a service is useful as you can see - in this case the chart is clearly associated with the service and it's nice that the graph generation can happen off a handler rather than through a page. Images are common resources, but output can also be PDF reports, zip files for downloads etc. which is becoming increasingly more common to be returned from REST endpoints and other applications. Why reinvent? Obviously the examples I've shown here are pretty basic in terms of functionality. But I hope they demonstrate the core features of AJAX callbacks that you need to work through in most applications which is simple: return data, send back data and potentially retrieve data in various formats. While there are other solutions when it comes down to making AJAX callbacks and servicing REST like requests, I like the flexibility my home grown solution provides. Simply put it's still the easiest solution that I've found that addresses my common use cases: AJAX JSON RPC style callbacks Url based access XML and JSON Output from single method endpoint XML and JSON POST support, querystring input, routing parameter mapping UrlEncoded POST data support on callbacks Ability to return stream/raw string data Essentially ability to return ANYTHING from Service and pass anything All these features are available in various solutions but not together in one place. I've been using this code base for over 4 years now in a number of projects both for myself and commercial work and it's served me extremely well. Besides the AJAX functionality CallbackHandler provides, it's also an easy way to create any kind of output endpoint I need to create. Need to create a few simple routines that spit back some data, but don't want to create a Page or View or full blown handler for it? Create a CallbackHandler and add a method or multiple methods and you have your generic endpoints.  It's a quick and easy way to add small code pieces that are pretty efficient as they're running through a pretty small handler implementation. I can have this up and running in a couple of minutes literally without any setup and returning just about any kind of data. Resources Download the Sample NuGet: Westwind Web and AJAX Utilities (Westwind.Web) ajaxCallMethod() Documentation Using the AjaxMethodCallback WebForms Control West Wind Web Toolkit Home Page West Wind Web Toolkit Source Code © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery  AJAX   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Table sorting & pagination with jQuery and Razor in ASP.NET MVC

    - by hajan
    Introduction jQuery enjoys living inside pages which are built on top of ASP.NET MVC Framework. The ASP.NET MVC is a place where things are organized very well and it is quite hard to make them dirty, especially because the pattern enforces you on purity (you can still make it dirty if you want so ;) ). We all know how easy is to build a HTML table with a header row, footer row and table rows showing some data. With ASP.NET MVC we can do this pretty easy, but, the result will be pure HTML table which only shows data, but does not includes sorting, pagination or some other advanced features that we were used to have in the ASP.NET WebForms GridView. Ok, there is the WebGrid MVC Helper, but what if we want to make something from pure table in our own clean style? In one of my recent projects, I’ve been using the jQuery tablesorter and tablesorter.pager plugins that go along. You don’t need to know jQuery to make this work… You need to know little CSS to create nice design for your table, but of course you can use mine from the demo… So, what you will see in this blog is how to attach this plugin to your pure html table and a div for pagination and make your table with advanced sorting and pagination features.   Demo Project Resources The resources I’m using for this demo project are shown in the following solution explorer window print screen: Content/images – folder that contains all the up/down arrow images, pagination buttons etc. You can freely replace them with your own, but keep the names the same if you don’t want to change anything in the CSS we will built later. Content/Site.css – The main css theme, where we will add the theme for our table too Controllers/HomeController.cs – The controller I’m using for this project Models/Person.cs – For this demo, I’m using Person.cs class Scripts – jquery-1.4.4.min.js, jquery.tablesorter.js, jquery.tablesorter.pager.js – required script to make the magic happens Views/Home/Index.cshtml – Index view (razor view engine) the other items are not important for the demo. ASP.NET MVC 1. Model In this demo I use only one Person class which defines Person entity with several properties. You can use your own model, maybe one which will access data from database or any other resource. Person.cs public class Person {     public string Name { get; set; }     public string Surname { get; set; }     public string Email { get; set; }     public int? Phone { get; set; }     public DateTime? DateAdded { get; set; }     public int? Age { get; set; }     public Person(string name, string surname, string email,         int? phone, DateTime? dateadded, int? age)     {         Name = name;         Surname = surname;         Email = email;         Phone = phone;         DateAdded = dateadded;         Age = age;     } } 2. View In our example, we have only one Index.chtml page where Razor View engine is used. Razor view engine is my favorite for ASP.NET MVC because it’s very intuitive, fluid and keeps your code clean. 3. Controller Since this is simple example with one page, we use one HomeController.cs where we have two methods, one of ActionResult type (Index) and another GetPeople() used to create and return list of people. HomeController.cs public class HomeController : Controller {     //     // GET: /Home/     public ActionResult Index()     {         ViewBag.People = GetPeople();         return View();     }     public List<Person> GetPeople()     {         List<Person> listPeople = new List<Person>();                  listPeople.Add(new Person("Hajan", "Selmani", "[email protected]", 070070070,DateTime.Now, 25));                     listPeople.Add(new Person("Straight", "Dean", "[email protected]", 123456789, DateTime.Now.AddDays(-5), 35));         listPeople.Add(new Person("Karsen", "Livia", "[email protected]", 46874651, DateTime.Now.AddDays(-2), 31));         listPeople.Add(new Person("Ringer", "Anne", "[email protected]", null, DateTime.Now, null));         listPeople.Add(new Person("O'Leary", "Michael", "[email protected]", 32424344, DateTime.Now, 44));         listPeople.Add(new Person("Gringlesby", "Anne", "[email protected]", null, DateTime.Now.AddDays(-9), 18));         listPeople.Add(new Person("Locksley", "Stearns", "[email protected]", 2135345, DateTime.Now, null));         listPeople.Add(new Person("DeFrance", "Michel", "[email protected]", 235325352, DateTime.Now.AddDays(-18), null));         listPeople.Add(new Person("White", "Johnson", null, null, DateTime.Now.AddDays(-22), 55));         listPeople.Add(new Person("Panteley", "Sylvia", null, 23233223, DateTime.Now.AddDays(-1), 32));         listPeople.Add(new Person("Blotchet-Halls", "Reginald", null, 323243423, DateTime.Now, 26));         listPeople.Add(new Person("Merr", "South", "[email protected]", 3232442, DateTime.Now.AddDays(-5), 85));         listPeople.Add(new Person("MacFeather", "Stearns", "[email protected]", null, DateTime.Now, null));         return listPeople;     } }   TABLE CSS/HTML DESIGN Now, lets start with the implementation. First of all, lets create the table structure and the main CSS. 1. HTML Structure @{     Layout = null;     } <!DOCTYPE html> <html> <head>     <title>ASP.NET & jQuery</title>     <!-- referencing styles, scripts and writing custom js scripts will go here --> </head> <body>     <div>         <table class="tablesorter">             <thead>                 <tr>                     <th> value </th>                 </tr>             </thead>             <tbody>                 <tr>                     <td>value</td>                 </tr>             </tbody>             <tfoot>                 <tr>                     <th> value </th>                 </tr>             </tfoot>         </table>         <div id="pager">                      </div>     </div> </body> </html> So, this is the main structure you need to create for each of your tables where you want to apply the functionality we will create. Of course the scripts are referenced once ;). As you see, our table has class tablesorter and also we have a div with id pager. In the next steps we will use both these to create the needed functionalities. The complete Index.cshtml coded to get the data from controller and display in the page is: <body>     <div>         <table class="tablesorter">             <thead>                 <tr>                     <th>Name</th>                     <th>Surname</th>                     <th>Email</th>                     <th>Phone</th>                     <th>Date Added</th>                 </tr>             </thead>             <tbody>                 @{                     foreach (var p in ViewBag.People)                     {                                 <tr>                         <td>@p.Name</td>                         <td>@p.Surname</td>                         <td>@p.Email</td>                         <td>@p.Phone</td>                         <td>@p.DateAdded</td>                     </tr>                     }                 }             </tbody>             <tfoot>                 <tr>                     <th>Name</th>                     <th>Surname</th>                     <th>Email</th>                     <th>Phone</th>                     <th>Date Added</th>                 </tr>             </tfoot>         </table>         <div id="pager" style="position: none;">             <form>             <img src="@Url.Content("~/Content/images/first.png")" class="first" />             <img src="@Url.Content("~/Content/images/prev.png")" class="prev" />             <input type="text" class="pagedisplay" />             <img src="@Url.Content("~/Content/images/next.png")" class="next" />             <img src="@Url.Content("~/Content/images/last.png")" class="last" />             <select class="pagesize">                 <option selected="selected" value="5">5</option>                 <option value="10">10</option>                 <option value="20">20</option>                 <option value="30">30</option>                 <option value="40">40</option>             </select>             </form>         </div>     </div> </body> So, mainly the structure is the same. I have added @Razor code to create table with data retrieved from the ViewBag.People which has been filled with data in the home controller. 2. CSS Design The CSS code I’ve created is: /* DEMO TABLE */ body {     font-size: 75%;     font-family: Verdana, Tahoma, Arial, "Helvetica Neue", Helvetica, Sans-Serif;     color: #232323;     background-color: #fff; } table { border-spacing:0; border:1px solid gray;} table.tablesorter thead tr .header {     background-image: url(images/bg.png);     background-repeat: no-repeat;     background-position: center right;     cursor: pointer; } table.tablesorter tbody td {     color: #3D3D3D;     padding: 4px;     background-color: #FFF;     vertical-align: top; } table.tablesorter tbody tr.odd td {     background-color:#F0F0F6; } table.tablesorter thead tr .headerSortUp {     background-image: url(images/asc.png); } table.tablesorter thead tr .headerSortDown {     background-image: url(images/desc.png); } table th { width:150px;            border:1px outset gray;            background-color:#3C78B5;            color:White;            cursor:pointer; } table thead th:hover { background-color:Yellow; color:Black;} table td { width:150px; border:1px solid gray;} PAGINATION AND SORTING Now, when everything is ready and we have the data, lets make pagination and sorting functionalities 1. jQuery Scripts referencing <link href="@Url.Content("~/Content/Site.css")" rel="stylesheet" type="text/css" /> <script src="@Url.Content("~/Scripts/jquery-1.4.4.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.tablesorter.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.tablesorter.pager.js")" type="text/javascript"></script> 2. jQuery Sorting and Pagination script   <script type="text/javascript">     $(function () {         $("table.tablesorter").tablesorter({ widthFixed: true, sortList: [[0, 0]] })         .tablesorterPager({ container: $("#pager"), size: $(".pagesize option:selected").val() });     }); </script> So, with only two lines of code, I’m using both tablesorter and tablesorterPager plugins, giving some options to both these. Options added: tablesorter - widthFixed: true – gives fixed width of the columns tablesorter - sortList[[0,0]] – An array of instructions for per-column sorting and direction in the format: [[columnIndex, sortDirection], ... ] where columnIndex is a zero-based index for your columns left-to-right and sortDirection is 0 for Ascending and 1 for Descending. A valid argument that sorts ascending first by column 1 and then column 2 looks like: [[0,0],[1,0]] (source: http://tablesorter.com/docs/) tablesorterPager – container: $(“#pager”) – tells the pager container, the div with id pager in our case. tablesorterPager – size: the default size of each page, where I get the default value selected, so if you put selected to any other of the options in your select list, you will have this number of rows as default per page for the table too. END RESULTS 1. Table once the page is loaded (default results per page is 5 and is automatically sorted by 1st column as sortList is specified) 2. Sorted by Phone Descending 3. Changed pagination to 10 items per page 4. Sorted by Phone and Name (use SHIFT to sort on multiple columns) 5. Sorted by Date Added 6. Page 3, 5 items per page   ADDITIONAL ENHANCEMENTS We can do additional enhancements to the table. We can make search for each column. I will cover this in one of my next blogs. Stay tuned. DEMO PROJECT You can download demo project source code from HERE.CONCLUSION Once you finish with the demo, run your page and open the source code. You will be amazed of the purity of your code.Working with pagination in client side can be very useful. One of the benefits is performance, but if you have thousands of rows in your tables, you will get opposite result when talking about performance. Hence, sometimes it is nice idea to make pagination on back-end. So, the compromise between both approaches would be best to combine both of them. I use at most up to 500 rows on client-side and once the user reach the last page, we can trigger ajax postback which can get the next 500 rows using server-side pagination of the same data. I would like to recommend the following blog post http://weblogs.asp.net/gunnarpeipman/archive/2010/09/14/returning-paged-results-from-repositories-using-pagedresult-lt-t-gt.aspx, which will help you understand how to return page results from repository. I hope this was helpful post for you. Wait for my next posts ;). Please do let me know your feedback. Best Regards, Hajan

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  • Data Formatters temporarily unavailable

    - by iphone newbie
    I'm currently working on an iPhone app. This app has a login screen, also a signup screen. After the user has successfully signed up, I dismiss the signup view, then the app automatically logs in using the created account. After which, the login view is dismissed, showing the main view. I'm trying to modify this by immediately dismissing the login view, since I already have the account details of the user when the signup is successful. Basically, the ideal flow is: after the user successfully signs up, I save the username and password in a singleton class, then dismiss the signup view. When I get to the parent view (which is the login screen), I have a variable that checks if there was a successful signup. If that variable is true, I want to immediately dismiss the login view. However, I come across this error message: Data Formatters temporarily unavailable, will re-try after a 'continue'. (Unknown error loading shared library "/Developer/usr/lib/libXcodeDebuggerSupport.dylib") I'm not really sure why this happens. I have no problems dismissing the login view when I go through the actual login procedure - which of course also dismisses the login view if the user inputs a correct username and password. I'm not exactly sure, but I'm starting to think that the iPhone cannot handle dismissing 2 view controllers almost at the same time. Is it possible that I'm dismissing the login view too quickly? Is that a factor? Is there anyway for me to be able to dismiss 2 view controllers almost simultaneously without coming across this error message?

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  • Encryption is hard: AES encryption to Hex

    - by Rob Cameron
    So, I've got an app at work that encrypts a string using ColdFusion. ColdFusion's bulit-in encryption helpers make it pretty simple: encrypt('string_to_encrypt','key','AES','HEX') What I'm trying to do is use Ruby to create the same encrypted string as this ColdFusion script is creating. Unfortunately encryption is the most confusing computer science subject known to man. I found a couple helper methods that use the openssl library and give you a really simple encryption/decryption method. Here's the resulting string: "\370\354D\020\357A\227\377\261G\333\314\204\361\277\250" Which looks unicode-ish to me. I've tried several libraries to convert this to hex but they all say it contains invalid characters. Trying to unpack it results in this: string = "\370\354D\020\357A\227\377\261G\333\314\204\361\277\250" string.unpack('U') ArgumentError: malformed UTF-8 character from (irb):19:in `unpack' from (irb):19 At the end of the day it's supposed to look like this (the output of the ColdFusion encrypt method): F8E91A689565ED24541D2A0109F201EF Of course that's assuming that all the padding, initialization vectors, salts, cypher types and a million other possible differences all line up. Here's the simple script I'm using to encrypt/decrypt: def aes(m,k,t) (aes = OpenSSL::Cipher::Cipher.new('aes-256-cbc').send(m)).key = Digest::SHA256.digest(k) aes.update(t) << aes.final end def encrypt(key, text) aes(:encrypt, key, text) end def decrypt(key, text) aes(:decrypt, key, text) end Any help? Maybe just a simple option I can pass to OpenSSL::Cipher::Cipher that will tell it to hex-encode the final string?

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