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  • How does one open multiple tabs in TextWrangler?

    - by Closure Cowboy
    No, I'm not bluffing. I really can't figure this out. The setup: I went to File -> Open, and then selected a directory rather than a file. As expected, a directory tree opened on the left side of my document. Hooray! I can easily view the files' structure in my Rails project. So, I make a few changes in a file, and then I click on a different file in the directory tree. My problem: TextWrangler then asks me whether I want to save my changes. Huh? I say "No", and the new document doesn't open at all. Great. I try hitting Command+N (new document). A new window opens. Ughhhh. How the heck do I open documents in a new tab? Note: I have set the "New & opened documents" behavior to "Open in the front window". This does not change the behavior described (i.e. when a directory is opened rather than a single file).

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  • Why does this rsnapshot exclude not work?

    - by bstpierre
    Rsnapshot passes excludes directly to rsync, but rsync's behavior appears inconsistent. I've simplified my rsnapshot backup test to the following directory tree (this tree will be backed up): gorilla:~# find /tmp/snaptest -exec file {} \; /tmp/snaptest: directory /tmp/snaptest/SKIPTHIS: directory /tmp/snaptest/SKIPTHIS/xyz: directory /tmp/snaptest/SKIPTHIS/xyz/testing: ASCII text /tmp/snaptest/SKIPTHIS/bar: ASCII text /tmp/snaptest/SKIPTHIS/foo: ASCII text /tmp/snaptest/SKIPTHIS.txt: ASCII text My config file: config_version 1.2 snapshot_root /tmp/backup-media no_create_root 1 cmd_cp /bin/cp cmd_rm /bin/rm cmd_rsync /usr/bin/rsync cmd_ssh /usr/bin/ssh cmd_logger /usr/bin/logger cmd_du /usr/bin/du interval hourly 6 interval daily 7 interval weekly 4 interval monthly 3 verbose 3 loglevel 3 logfile /media/maxtor-one-touch/rsnapshot.log lockfile /media/maxtor-one-touch/backups/.rsnapshot.pid rsync_short_args -a rsync_long_args --delete --numeric-ids --relative --delete-excluded exclude "SKIPTHIS/**" link_dest 1 backup /tmp/snaptest snaptest The result: gorilla:~# rsnapshot -c /tmp/snaptest.conf hourly echo 12638 > /media/maxtor-one-touch/backups/.rsnapshot.pid mkdir -m 0755 -p /tmp/backup-media/hourly.0/ /usr/bin/rsync -a --delete --numeric-ids --relative --delete-excluded \ --exclude="SKIPTHIS/**" /tmp/snaptest \ /tmp/backup-media/hourly.0/snaptest touch /tmp/backup-media/hourly.0/ rm -f /media/maxtor-one-touch/backups/.rsnapshot.pid gorilla:~# find /tmp/backup-media/ -exec file {} \; /tmp/backup-media/: directory /tmp/backup-media/hourly.0: directory /tmp/backup-media/hourly.0/snaptest: directory /tmp/backup-media/hourly.0/snaptest/tmp: sticky directory /tmp/backup-media/hourly.0/snaptest/tmp/snaptest: directory /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS: directory /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS/xyz: directory /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS/xyz/testing: ASCII text /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS/bar: ASCII text /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS/foo: ASCII text /tmp/backup-media/hourly.0/snaptest/tmp/snaptest/SKIPTHIS.txt: ASCII text My confusion stems from the fact that if I copy-paste the rsync command echoed by rsnapshot, the SKIPTHIS directory is excluded! (I've tested with various other SKIPTHIS patterns with the same results.) Any idea what's going on?

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  • Why does redis report limit of 1024 files even after update to limits.conf?

    - by esilver
    I see this error at the top of my redis.log file: Current maximum open files is 1024. maxclients has been reduced to 4064 to compensate for low ulimit. I have followed these steps to the letter (and rebooted): Moreover, I see this when I run ulimit: ubuntu@ip-XX-XXX-XXX-XXX:~$ ulimit -n 65535 Is this error specious? If not, what other steps do I need to perform? I am running redis 2.8.13 (tip of the tree) on Ubuntu LTS 14.04.1 (again, tip of the tree). Here is the user info: ubuntu@ip-XX-XXX-XXX-XXX:~$ ps aux | grep redis root 1027 0.0 0.0 66328 2112 ? Ss 20:30 0:00 sudo -u ubuntu /usr/local/bin/redis-server /etc/redis/redis.conf ubuntu 1107 19.2 48.8 7629152 7531552 ? Sl 20:30 2:21 /usr/local/bin/redis-server *:6379 The server is therefore running as ubuntu. Here are my limits.conf file without comments: ubuntu@ip-XX-XXX-XXX-XXX:~$ cat /etc/security/limits.conf | sed '/^#/d;/^$/d' ubuntu soft nofile 65535 ubuntu hard nofile 65535 root soft nofile 65535 root hard nofile 65535 And here is the output of sysctl fs.file-max: ubuntu@ip-XX-XXX-XXX-XXX:~$ sysctl -a| grep fs.file-max sysctl: permission denied on key 'fs.protected_hardlinks' sysctl: permission denied on key 'fs.protected_symlinks' fs.file-max = 1528687 sysctl: permission denied on key 'kernel.cad_pid' sysctl: permission denied on key 'kernel.usermodehelper.bset' sysctl: permission denied on key 'kernel.usermodehelper.inheritable' sysctl: permission denied on key 'net.ipv4.tcp_fastopen_key' as sudo ubuntu@ip-10-102-154-226:~$ sudo sysctl -a| grep fs.file-max fs.file-max = 1528687 Also, I see this error at the top of the redis.log file, not sure if it's related. It makes sense that the ubuntu user isn't allowed to change max open files, but given the high ulimits I have tried to set he shouldn't need to: [1050] 23 Aug 21:00:43.572 # You requested maxclients of 10000 requiring at least 10032 max file descriptors. [1050] 23 Aug 21:00:43.572 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted.

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  • Knowledge and user generated content management system to track files, research, proposals, etc.?

    - by Eshwar
    I'll try keep it short. Here's the scenario: We have employees all over the world performing similar work i.e. research, generating powerpoint slides, word documents, graphics, etc. Many times a lot of this previous work can be reused for another future project. The current arrangement is email and phone calls which as you would agree is quick if you know where to look but otherwise archaic and very very inefficient. So I am looking for software that will allow me to do the following: Tag files e.g. an investor presentation on cellphone usage in kenya would be tagged investor, cellphone, kenya Manage references e.g. if we read something on the internet, should be able to paste that link in some fashion and tag it as above. Preferably cloud based so that it can be accessed by anybody and additionally would be nice (though NOT must) to have access levels (director, manager, everyone) A nice interface that non technically savvy folks can warm up to ;) A desktop app would be handy so that people don't always have to click upload or something A tree based system is inefficient in this case because content is usually linked across branches and also people might not quite agree on one format of a tree. Tagging works around this very nicely. What I have considered so far: Evernote (for its more professional look) Springpad (for its versatility with content) Mendeley (this is a research manager and in some ways ideal, but i fear its limited to PDFs) The goal is that when somebody wants to look for a document, they don't have to ask a colleague, they can just search with keywords and all relevant information shows up. Thanks!

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  • IIS 6 ASP.NET default handler-mappings and virtual directories

    - by Mark Lauter
    I'm having a problem with setting a default mapping in IIS 6. I want to secure *.HTML files with ASP.NET forms authentication. The problem seems to have something to do with using virtual directories to hold the html files. Here's how it's setup: sample directory tree c:/inetpub/ (nothing in here) d:/web_files/my_web_apps d:/web_files/my_web_apps/app1/ d:/web_files/my_web_apps/app2/ d:/web_files/my_web_apps/html_files/ app1 and app2 both access the same html_files directory, so html_files is set as a virtual directory in the web apps in IIS... sample web directory tree //app1/html_files/ (points to physical directory: d:/web_files/my_web_apps/html_files/) //app2/html_files/ (points to physical directory: d:/web_files/my_web_apps/html_files/) If I put a file called test.html in the root of //app1/ and then add the default mapping to the asp.net dll and setup my security on the root folder with deny="?", then accessing test.html works exactly as expected. If I'm not authenticated, it takes me to the login.aspx page, and if I am authenticated then it displays test.html. If I put the test.html file in the html_files directory I get a totally different behavior. Now the login.aspx page loads and I stuck some code in to check if I was still authenticated: <p>autheticated: <%=User.Identity.IsAuthenticated%></p> I figured it would say false because why else would it bother to load the login page? Nope, it says true - so it knows i'm authenticated, but it won't give me access to the test.html file. I've spent several hours on this and haven't been able to solve it. I'm going to spend some more time on google to see if I've missed something. Fingers crossed.

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  • Which isn't working on linode servers (Ubuntu 10.04)?

    - by chrisjlee
    Currently trying to configure a linode server running on ubuntu 10.04. I utilized a stackscript (Default drupal profile) which seemed to run successfully. The log indicate so as well. Then ssh'd into the server (as root) to try to configure php. When i run a which php, which php5 they both return nothing. A which python returns something though. I know where the default path to php but i usually just like to use it as confirmation that php exists. Do i have to modify some configurations to enable which to work? Also tab completion doesn't seem to work for when i apt-get install? Update: Thanks for the suggestions guys. I've ran a couple commands and no luck either: [ root@ ~ ] $ dpkg -l |grep php [ root@ ~ ] $ apt-get install php5-cli Reading package lists... Done Building dependency tree Reading state information... Done Package php5-cli is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package php5-cli has no installation candidate Then i tried installing php and php cli: [ root@ ~ ] $ sudo apt-get install php5 php5-cli sudo: unable to resolve host xxxxxxx Reading package lists... Done Building dependency tree Reading state information... Done Package php5 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package php5 has no installation candidate

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  • Why won't Media Monkey add one particular folder of mp3's?

    - by ChrisF
    I'm using the latest and greatest version on Media Monkey (free version) and it won't find the mp3's in one particular folder in my music tree. It can see all the other files in the tree and the folder shows up when I click Add/Rescan files to the library... I have full control over the folder and all the files in the folder. The files play in Windows Media Player. The files play in Media Monkey if I right click and play from the context menu. All the tracks are at least 2 minutes long and over 5MB long and Media Monkey is set to ignore files shorter than 20KB and include all files regardless of length. There was an issue in that the that the genre of the tracks was set to "Classical" and the option that allows you to browse the classical music independently of the other music isn't enabled in the free version. It's a Gold version option only. I hadn't spotted that my other classical music was also missing from the library (I have rather a large library). Once I retagged the music with a different tag and tried to add the files again it reported that it added the tracks, but they still didn't show up in the library.

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  • Outlook 2007 - Mailbox doesn't show my Items (like Calendar)

    - by cyntaxx
    Hi All, I have running an Exchange Server 2003 and 2 IBM Laptops (A&B)with XP SP3. On both Laptops Office 2007 is installed. Laptop "A" Outlook doesn't show me my Calendar and Notes entries in my mailbox tree on Laptop "A". I can click on the calenendar tab and the entries are there. On Laptop "B" it is working fine. I know that I can make a "rigth click" on "mailbox" and choose "create new folder". Than I select i.g. my calendar. It creates it, but I can't access it through my mailbox tree. Clicking on the Calendar tab works fine again. So, the mailbox is fine (I think). There must be failure with Outlook. I tried these commands here with no positive result. Outlook /cleanviews Outlook /resetfolders I want to avoid a repair installation of Outlook, because the whole office needs to be repaired. (And both laptops belong to my boss) :) Thanks, Toby

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  • Ajax Control Toolkit December 2013 Release

    - by Stephen.Walther
    Today, we released a new version of the Ajax Control Toolkit that contains several important bug fixes and new features. The new release contains a new Tabs control that has been entirely rewritten in jQuery. You can download the December 2013 release of the Ajax Control Toolkit at http://Ajax.CodePlex.com. Alternatively, you can install the latest version directly from NuGet: The Ajax Control Toolkit and jQuery The Ajax Control Toolkit now contains two controls written with jQuery: the ToggleButton control and the Tabs control.  The goal is to rewrite the Ajax Control Toolkit to use jQuery instead of the Microsoft Ajax Library gradually over time. The motivation for rewriting the controls in the Ajax Control Toolkit to use jQuery is to modernize the toolkit. We want to continue to accept new controls written for the Ajax Control Toolkit contributed by the community. The community wants to use jQuery. We want to make it easy for the community to submit bug fixes. The community understands jQuery. Using the Ajax Control Toolkit with a Website that Already uses jQuery But what if you are already using jQuery in your website?  Will adding the Ajax Control Toolkit to your website break your existing website?  No, and here is why. The Ajax Control Toolkit uses jQuery.noConflict() to avoid conflicting with an existing version of jQuery in a page.  The version of jQuery that the Ajax Control Toolkit uses is represented by a variable named actJQuery.  You can use actJQuery side-by-side with an existing version of jQuery in a page without conflict.Imagine, for example, that you add jQuery to an ASP.NET page using a <script> tag like this: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="TestACTDec2013.WebForm1" %> <!DOCTYPE html> <html > <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <script src="Scripts/jquery-2.0.3.min.js"></script> <ajaxToolkit:ToolkitScriptManager runat="server" /> <ajaxToolkit:TabContainer runat="server"> <ajaxToolkit:TabPanel runat="server"> <HeaderTemplate> Tab 1 </HeaderTemplate> <ContentTemplate> <h1>First Tab</h1> </ContentTemplate> </ajaxToolkit:TabPanel> <ajaxToolkit:TabPanel runat="server"> <HeaderTemplate> Tab 2 </HeaderTemplate> <ContentTemplate> <h1>Second Tab</h1> </ContentTemplate> </ajaxToolkit:TabPanel> </ajaxToolkit:TabContainer> </div> </form> </body> </html> The page above uses the Ajax Control Toolkit Tabs control (TabContainer and TabPanel controls).  The Tabs control uses the version of jQuery that is currently bundled with the Ajax Control Toolkit (jQuery version 1.9.1). The page above also includes a <script> tag that references jQuery version 2.0.3.  You might need that particular version of jQuery, for example, to use a particular jQuery plugin. The two versions of jQuery in the page do not create a conflict. This fact can be demonstrated by entering the following two commands in the JavaScript console window: actJQuery.fn.jquery $.fn.jquery Typing actJQuery.fn.jquery will display the version of jQuery used by the Ajax Control Toolkit and typing $.fn.jquery (or jQuery.fn.jquery) will show the version of jQuery used by other jQuery plugins in the page.      Preventing jQuery from Loading Twice So by default, the Ajax Control Toolkit will not conflict with any existing version of jQuery used in your application. However, this does mean that if you are already using jQuery in your application then jQuery will be loaded twice. For performance reasons, you might want to avoid loading the jQuery library twice. By taking advantage of the <remove> element in the AjaxControlToolkit.config file, you can prevent the Ajax Control Toolkit from loading its version of jQuery. <ajaxControlToolkit> <scripts> <remove name="jQuery.jQuery.js" /> </scripts> <controlBundles> <controlBundle> <control name="TabContainer" /> <control name="TabPanel" /> </controlBundle> </controlBundles> </ajaxControlToolkit> Be careful here:  the name of the script being removed – jQuery.jQuery.js – is case-sensitive. If you remove jQuery then it is your responsibility to add the exact same version of jQuery back into your application.  You can add jQuery back using a <script> tag like this: <script src="Scripts/jquery-1.9.1.min.js"></script>     Make sure that you add the <script> tag before the server-side <form> tag or the Ajax Control Toolkit won’t detect the presence of jQuery. Alternatively, you can use the ToolkitScriptManager like this: <ajaxToolkit:ToolkitScriptManager runat="server"> <Scripts> <asp:ScriptReference Name="jQuery.jQuery.js" /> </Scripts> </ajaxToolkit:ToolkitScriptManager> The Ajax Control Toolkit is tested against the particular version of jQuery that is bundled with the Ajax Control Toolkit. Currently, the Ajax Control Toolkit uses jQuery version 1.9.1. If you attempt to use a different version of jQuery with the Ajax Control Toolkit then you will get the exception jQuery 1.9.1 is required in your JavaScript console window: If you need to use a different version of jQuery in the same page as the Ajax Control Toolkit then you should not use the <remove> element. Instead, allow the Ajax Control Toolkit to load its version of jQuery side-by-side with the other version of jQuery. Lots of Bug Fixes As usual, we implemented several important bug fixes with this release. The bug fixes concerned the following three controls: Tabs control – In the course of rewriting the Tabs control to use jQuery, we fixed several bugs related to the Tabs control. AjaxFileUpload control – We resolved an issue concerning the AjaxFileUpload and the TMP directory. HTMLEditor control – We updated the HTMLEditor control to use the new Ajax Control Toolkit bundling and minification framework. Summary I would like to thank the Superexpert team for their hard work on this release. Many long hours of coding and testing went into making this release possible.

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  • Source-control 'wet-work'?

    - by Phil Factor
    When a design or creative work is flawed beyond remedy, it is often best to destroy it and start again. The other day, I lost the code to a long and intricate SQL batch I was working on. I’d thought it was impossible, but it happened. With all the technology around that is designed to prevent this occurring, this sort of accident has become a rare event.  If it weren’t for a deranged laptop, and my distraction, the code wouldn’t have been lost this time.  As always, I sighed, had a soothing cup of tea, and typed it all in again.  The new code I hastily tapped in  was much better: I’d held in my head the essence of how the code should work rather than the details: I now knew for certain  the start point, the end, and how it should be achieved. Instantly the detritus of half-baked thoughts fell away and I was able to write logical code that performed better.  Because I could work so quickly, I was able to hold the details of all the columns and variables in my head, and the dynamics of the flow of data. It was, in fact, easier and quicker to start from scratch rather than tidy up and refactor the existing code with its inevitable fumbling and half-baked ideas. What a shame that technology is now so good that developers rarely experience the cleansing shock of losing one’s code and having to rewrite it from scratch.  If you’ve never accidentally lost  your code, then it is worth doing it deliberately once for the experience. Creative people have, until Technology mistakenly prevented it, torn up their drafts or sketches, threw them in the bin, and started again from scratch.  Leonardo’s obsessive reworking of the Mona Lisa was renowned because it was so unusual:  Most artists have been utterly ruthless in destroying work that didn’t quite make it. Authors are particularly keen on writing afresh, and the results are generally positive. Lawrence of Arabia actually lost the entire 250,000 word manuscript of ‘The Seven Pillars of Wisdom’ by accidentally leaving it on a train at Reading station, before rewriting a much better version.  Now, any writer or artist is seduced by technology into altering or refining their work rather than casting it dramatically in the bin or setting a light to it on a bonfire, and rewriting it from the blank page.  It is easy to pick away at a flawed work, but the real creative process is far more brutal. Once, many years ago whilst running a software house that supplied commercial software to local businesses, I’d been supervising an accounting system for a farming cooperative. No packaged system met their needs, and it was all hand-cut code.  For us, it represented a breakthrough as it was for a government organisation, and success would guarantee more contracts. As you’ve probably guessed, the code got mangled in a disk crash just a week before the deadline for delivery, and the many backups all proved to be entirely corrupted by a faulty tape drive.  There were some fragments left on individual machines, but they were all of different versions.  The developers were in despair.  Strangely, I managed to re-write the bulk of a three-month project in a manic and caffeine-soaked weekend.  Sure, that elegant universally-applicable input-form routine was‘nt quite so elegant, but it didn’t really need to be as we knew what forms it needed to support.  Yes, the code lacked architectural elegance and reusability. By dawn on Monday, the application passed its integration tests. The developers rose to the occasion after I’d collapsed, and tidied up what I’d done, though they were reproachful that some of the style and elegance had gone out of the application. By the delivery date, we were able to install it. It was a smaller, faster application than the beta they’d seen and the user-interface had a new, rather Spartan, appearance that we swore was done to conform to the latest in user-interface guidelines. (we switched to Helvetica font to look more ‘Bauhaus’ ). The client was so delighted that he forgave the new bugs that had crept in. I still have the disk that crashed, up in the attic. In IT, we have had mixed experiences from complete re-writes. Lotus 123 never really recovered from a complete rewrite from assembler into C, Borland made the mistake with Arago and Quattro Pro  and Netscape’s complete rewrite of their Navigator 4 browser was a white-knuckle ride. In all cases, the decision to rewrite was a result of extreme circumstances where no other course of action seemed possible.   The rewrite didn’t come out of the blue. I prefer to remember the rewrite of Minix by young Linus Torvalds, or the rewrite of Bitkeeper by a slightly older Linus.  The rewrite of CP/M didn’t do too badly either, did it? Come to think of it, the guy who decided to rewrite the windowing system of the Xerox Star never regretted the decision. I’ll agree that one should often resist calls for a rewrite. One of the worst habits of the more inexperienced programmer is to denigrate whatever code he or she inherits, and then call loudly for a complete rewrite. They are buoyed up by the mistaken belief that they can do better. This, however, is a different psychological phenomenon, more related to the idea of some motorcyclists that they are operating on infinite lives, or the occasional squaddies that if they charge the machine-guns determinedly enough all will be well. Grim experience brings out the humility in any experienced programmer.  I’m referring to quite different circumstances here. Where a team knows the requirements perfectly, are of one mind on methodology and coding standards, and they already have a solution, then what is wrong with considering  a complete rewrite? Rewrites are so painful in the early stages, until that point where one realises the payoff, that even I quail at the thought. One needs a natural disaster to push one over the edge. The trouble is that source-control systems, and disaster recovery systems, are just too good nowadays.   If I were to lose this draft of this very blog post, I know I’d rewrite it much better. However, if you read this, you’ll know I didn’t have the nerve to delete it and start again.  There was a time that one prayed that unreliable hardware would deliver you from an unmaintainable mess of a codebase, but now technology has made us almost entirely immune to such a merciful act of God. An old friend of mine with long experience in the software industry has long had the idea of the ‘source-control wet-work’,  where one hires a malicious hacker in some wild eastern country to hack into one’s own  source control system to destroy all trace of the source to an application. Alas, backup systems are just too good to make this any more than a pipedream. Somehow, it would be difficult to promote the idea. As an alternative, could one construct a source control system that, on doing all the code-quality metrics, would systematically destroy all trace of source code that failed the quality test? Alas, I can’t see many managers buying into the idea. In reading the full story of the near-loss of Toy Story 2, it set me thinking. It turned out that the lucky restoration of the code wasn’t the happy ending one first imagined it to be, because they eventually came to the conclusion that the plot was fundamentally flawed and it all had to be rewritten anyway.  Was this an early  case of the ‘source-control wet-job’?’ It is very hard nowadays to do a rapid U-turn in a development project because we are far too prone to cling to our existing source-code.

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  • Source-control 'wet-work'?

    - by Phil Factor
    When a design or creative work is flawed beyond remedy, it is often best to destroy it and start again. The other day, I lost the code to a long and intricate SQL batch I was working on. I’d thought it was impossible, but it happened. With all the technology around that is designed to prevent this occurring, this sort of accident has become a rare event.  If it weren’t for a deranged laptop, and my distraction, the code wouldn’t have been lost this time.  As always, I sighed, had a soothing cup of tea, and typed it all in again.  The new code I hastily tapped in  was much better: I’d held in my head the essence of how the code should work rather than the details: I now knew for certain  the start point, the end, and how it should be achieved. Instantly the detritus of half-baked thoughts fell away and I was able to write logical code that performed better.  Because I could work so quickly, I was able to hold the details of all the columns and variables in my head, and the dynamics of the flow of data. It was, in fact, easier and quicker to start from scratch rather than tidy up and refactor the existing code with its inevitable fumbling and half-baked ideas. What a shame that technology is now so good that developers rarely experience the cleansing shock of losing one’s code and having to rewrite it from scratch.  If you’ve never accidentally lost  your code, then it is worth doing it deliberately once for the experience. Creative people have, until Technology mistakenly prevented it, torn up their drafts or sketches, threw them in the bin, and started again from scratch.  Leonardo’s obsessive reworking of the Mona Lisa was renowned because it was so unusual:  Most artists have been utterly ruthless in destroying work that didn’t quite make it. Authors are particularly keen on writing afresh, and the results are generally positive. Lawrence of Arabia actually lost the entire 250,000 word manuscript of ‘The Seven Pillars of Wisdom’ by accidentally leaving it on a train at Reading station, before rewriting a much better version.  Now, any writer or artist is seduced by technology into altering or refining their work rather than casting it dramatically in the bin or setting a light to it on a bonfire, and rewriting it from the blank page.  It is easy to pick away at a flawed work, but the real creative process is far more brutal. Once, many years ago whilst running a software house that supplied commercial software to local businesses, I’d been supervising an accounting system for a farming cooperative. No packaged system met their needs, and it was all hand-cut code.  For us, it represented a breakthrough as it was for a government organisation, and success would guarantee more contracts. As you’ve probably guessed, the code got mangled in a disk crash just a week before the deadline for delivery, and the many backups all proved to be entirely corrupted by a faulty tape drive.  There were some fragments left on individual machines, but they were all of different versions.  The developers were in despair.  Strangely, I managed to re-write the bulk of a three-month project in a manic and caffeine-soaked weekend.  Sure, that elegant universally-applicable input-form routine was‘nt quite so elegant, but it didn’t really need to be as we knew what forms it needed to support.  Yes, the code lacked architectural elegance and reusability. By dawn on Monday, the application passed its integration tests. The developers rose to the occasion after I’d collapsed, and tidied up what I’d done, though they were reproachful that some of the style and elegance had gone out of the application. By the delivery date, we were able to install it. It was a smaller, faster application than the beta they’d seen and the user-interface had a new, rather Spartan, appearance that we swore was done to conform to the latest in user-interface guidelines. (we switched to Helvetica font to look more ‘Bauhaus’ ). The client was so delighted that he forgave the new bugs that had crept in. I still have the disk that crashed, up in the attic. In IT, we have had mixed experiences from complete re-writes. Lotus 123 never really recovered from a complete rewrite from assembler into C, Borland made the mistake with Arago and Quattro Pro  and Netscape’s complete rewrite of their Navigator 4 browser was a white-knuckle ride. In all cases, the decision to rewrite was a result of extreme circumstances where no other course of action seemed possible.   The rewrite didn’t come out of the blue. I prefer to remember the rewrite of Minix by young Linus Torvalds, or the rewrite of Bitkeeper by a slightly older Linus.  The rewrite of CP/M didn’t do too badly either, did it? Come to think of it, the guy who decided to rewrite the windowing system of the Xerox Star never regretted the decision. I’ll agree that one should often resist calls for a rewrite. One of the worst habits of the more inexperienced programmer is to denigrate whatever code he or she inherits, and then call loudly for a complete rewrite. They are buoyed up by the mistaken belief that they can do better. This, however, is a different psychological phenomenon, more related to the idea of some motorcyclists that they are operating on infinite lives, or the occasional squaddies that if they charge the machine-guns determinedly enough all will be well. Grim experience brings out the humility in any experienced programmer.  I’m referring to quite different circumstances here. Where a team knows the requirements perfectly, are of one mind on methodology and coding standards, and they already have a solution, then what is wrong with considering  a complete rewrite? Rewrites are so painful in the early stages, until that point where one realises the payoff, that even I quail at the thought. One needs a natural disaster to push one over the edge. The trouble is that source-control systems, and disaster recovery systems, are just too good nowadays.   If I were to lose this draft of this very blog post, I know I’d rewrite it much better. However, if you read this, you’ll know I didn’t have the nerve to delete it and start again.  There was a time that one prayed that unreliable hardware would deliver you from an unmaintainable mess of a codebase, but now technology has made us almost entirely immune to such a merciful act of God. An old friend of mine with long experience in the software industry has long had the idea of the ‘source-control wet-work’,  where one hires a malicious hacker in some wild eastern country to hack into one’s own  source control system to destroy all trace of the source to an application. Alas, backup systems are just too good to make this any more than a pipedream. Somehow, it would be difficult to promote the idea. As an alternative, could one construct a source control system that, on doing all the code-quality metrics, would systematically destroy all trace of source code that failed the quality test? Alas, I can’t see many managers buying into the idea. In reading the full story of the near-loss of Toy Story 2, it set me thinking. It turned out that the lucky restoration of the code wasn’t the happy ending one first imagined it to be, because they eventually came to the conclusion that the plot was fundamentally flawed and it all had to be rewritten anyway.  Was this an early  case of the ‘source-control wet-job’?’ It is very hard nowadays to do a rapid U-turn in a development project because we are far too prone to cling to our existing source-code.

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  • doubt regarding carrying data in custom events using actionscript

    - by user267530
    Hi I am working on actionscript to generate a SWF dynamically using JSON data coming from an HTTP request. I receive the data on creationComplete and try to generate a tree like structure. I don’t create the whole tree at the same time. I create 2 levels, level 1 and level 2. My goal is to attach custom events on the panels which represent tree nodes. When users click the panels, it dispatches custom events and try to generate the next level. So, it goes like this : On creation complete - get JSON- create top tow levels - click on level 2- create the level 2 and level 3 - click on level 3- create level 3 and 4. …and so on and so on. I am attaching my code with this email. Please take a look at it and if you have any hints on how you would do this if you need to paint a tree having total level number = “n” where( 0 import com.iwobanas.effects.*; import flash.events.MouseEvent; import flash.filters.BitmapFilterQuality; import flash.filters.BitmapFilterType; import flash.filters.GradientGlowFilter; import mx.controls.Alert; private var roundedMask:Sprite; private var panel:NewPanel; public var oldPanelIds:Array = new Array(); public var pages:Array = new Array();//cleanup public var delPages:Array = new Array(); public function DrawPlaybook(pos:Number,title:String,chld:Object):void { panel = new NewPanel(chld); panel.title = title; panel.name=title; panel.width = 100; panel.height = 80; panel.x=pos+5; panel.y=40; // Define a gradient glow. var gradientGlow:GradientGlowFilter = new GradientGlowFilter(); gradientGlow.distance = 0; gradientGlow.angle = 45; gradientGlow.colors = [0xFFFFF0, 0xFFFFFF]; gradientGlow.alphas = [0, 1]; gradientGlow.ratios = [0, 255]; gradientGlow.blurX = 10; gradientGlow.blurY = 10; gradientGlow.strength = 2; gradientGlow.quality = BitmapFilterQuality.HIGH; gradientGlow.type = BitmapFilterType.OUTER; panel.filters =[gradientGlow]; this.rawChildren.addChild(panel); pages.push(panel); panel.addEventListener(MouseEvent.CLICK, function(e:MouseEvent){onClickHandler(e,title,chld)}); this.addEventListener(CustomPageClickEvent.PANEL_CLICKED, function(e:CustomPageClickEvent){onCustomPanelClicked(e,title)}); } public function onClickHandler(e:MouseEvent,title:String,chld:Object):void { //var panel:Panel; for each(var stp1:NewPanel in pages){ if(stp1.title==title){ var eventObj:CustomPageClickEvent = new CustomPageClickEvent("panelClicked"); eventObj.panelClicked = stp1; dispatchEvent(eventObj); } } } private function onCustomPanelClicked(e:CustomPageClickEvent,title:String):void { //cleanup itself Alert.show("onCustomPanelClicked" + title); var panel:NewPanel; for each(var stp:NewPanel in pages){ startAnimation(e,stp); } if(title == e.panelClicked.title){ panel = new NewPanel(null); panel.title = title; panel.name=title; panel.width = 150; panel.height = 80; panel.x=100; panel.y=40; this.rawChildren.addChild(panel); // var slideRight:SlideRight = new SlideRight(); slideRight.target=panel; slideRight.duration=750; slideRight.showTarget=true; slideRight.play(); //draw the steps var jsonData = this.map.getValue(title); var posX:Number = 50; var posY:Number = 175; for each ( var pnl:NewPanel in pages){ pages.pop(); } for each ( var stp1:Object in jsonData.children){ //Alert.show("map step=" + stp.text ); panel = new NewPanel(null); panel.title = stp1.text; panel.name=stp1.id; panel.width = 100; panel.id=stp1.id; panel.height = 80; panel.x = posX; panel.y=posY; posX+=150; var s:String="hi" + stp1.text; panel.addEventListener(MouseEvent.CLICK, function(e:MouseEvent){onChildClick(e,s);}); this.addEventListener(CustomPageClickEvent.PANEL_CLICKED, function(e:CustomPageClickEvent){onCustomPnlClicked(e)}); this.rawChildren.addChild(panel); // Alert.show("map step=" + this.getChildIndex(panel) ); // oldPanelIds.push(panel); pages.push(panel); //this.addEventListener(CustomPageClickEvent.PANEL_CLICKED, //function(e:CustomPageClickEvent){onCustomPanelClicked(e,title)}); var slide:SlideUp = new SlideUp(); slide.target=panel; slide.duration=1500; slide.showTarget=false; slide.play(); } } } public function onChildClick(e:MouseEvent,s:String):void { //var panel:Panel; //Alert.show(e.currentTarget.title); for each(var stp1:NewPanel in pages){ if(stp1.title==e.currentTarget.title){ var eventObj:CustomPageClickEvent = new CustomPageClickEvent("panelClicked"); eventObj.panelClicked = stp1; dispatchEvent(eventObj); } } } private function onCustomPnlClicked(e:CustomPageClickEvent):void { for each ( var pnl:NewPanel in pages){ pages.pop(); } //onCustomPanelClicked(e,e.currentTarget.title); //Alert.show("hi from cstm" + e.panelClicked.title); } private function fadePanel(event:Event,panel:NewPanel):void{ panel.alpha -= .005; if (panel.alpha <= 0){ //Alert.show(panel.title); panel.removeEventListener(Event.ENTER_FRAME, function(e:Event){fadePanel(e,panel);}); }; panel.title=""; } private function startAnimation(event:CustomPageClickEvent,panel:NewPanel):void{ panel.addEventListener(Event.ENTER_FRAME, function(e:Event){fadePanel(e,panel)}); } Thanks in advance. Palash

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

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

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  • Any tool to make git build every commit to a branch in a seperate repository?

    - by Wayne
    A git tool that meets the specs below is needed. Does one already exists? If not, I will create a script and make it available on GitHub for others to use or contribute. Is there a completely different and better way to solve the need to build/test every commit to a branch in a git repository? Not just to the latest but each one back to a certain staring point. Background: Our development environment uses a separate continuous integration server which is wonderful. However, it is still necessary to do full builds locally on each developer's PC to make sure the commit won't "break the build" when pushed to the CI server. Unfortunately, with auto unit tests, those build force the developer to wait 10 or 15 minutes for a build every time. To solve this we have setup a "mirror" git repository on each developer PC. So we develop in the main repository but anytime a local full build is needed. We run a couple commands in a in the mirror repository to fetch, checkout the commit we want to build, and build. It's works extremely lovely so we can continue working in the main one with the build going in parallel. There's only one main concern now. We want to make sure every single commit builds and tests fine. But we often get busy and neglect to build several fresh commits. Then if it the build fails you have to do a bisect or manually figure build each interim commit to figure out which one broke. Requirements for this tool. The tool will look at another repo, origin by default, fetch and compare all commits that are in branches to 2 lists of commits. One list must hold successfully built commits and the other lists commits that failed. It identifies any commit or commits not yet in either list and begins to build them in a loop in the order that they were committed. It stops on the first one that fails. The tool appropriately adds each commit to either the successful or failed list after it as attempted to build each one. The tool will ignore any "legacy" commits which are prior to the oldest commit in the success list. This logic makes the starting point possible in the next point. Starting Point. The tool building a specific commit so that, if successful it gets added to the success list. If it is the earliest commit in the success list, it becomes the "starting point" so that none of the commits prior to that are examined for builds. Only linear tree support? Much like bisect, this tool works best on a commit tree which is, at least from it's starting point, linear without any merges. That is, it should be a tree which was built and updated entirely via rebase and fast forward commits. If it fails on one commit in a branch it will stop without building the rest that followed after that one. Instead if will just move on to another branch, if any. The tool must do these steps once by default but allow a parameter to loop with an option to set how many seconds between loops. Other tools like Hudson or CruiseControl could do more fancy scheduling options. The tool must have good defaults but allow optional control. Which repo? origin by default. Which branches? all of them by default. What tool? by default an executable file to be provided by the user named "buildtest", "buildtest.sh" "buildtest.cmd", or buildtest.exe" in the root folder of the repository. Loop delay? run once by default with option to loop after a number of seconds between iterations.

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  • ObjectContext.SaveChanges() fails with SQL CE

    - by David Veeneman
    I am creating a model-first Entity Framework 4 app that uses SQL CE as its data store. All is well until I call ObjectContext.SaveChanges() to save changes to the entities in the model. At that point, SaveChanges() throws a System.Data.UpdateException, with an inner exception message that reads as follows: Server-generated keys and server-generated values are not supported by SQL Server Compact. I am completely puzzled by this message. Any idea what is going on and how to fix it? Thanks. Here is the Exception dump: System.Data.UpdateException was unhandled Message=An error occurred while updating the entries. See the inner exception for details. Source=System.Data.Entity StackTrace: at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter) at System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache) at System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options) at System.Data.Objects.ObjectContext.SaveChanges() at FsDocumentationBuilder.ViewModel.Commands.SaveFileCommand.Execute(Object parameter) in D:\Users\dcveeneman\Documents\Visual Studio 2010\Projects\FsDocumentationBuilder\FsDocumentationBuilder\ViewModel\Commands\SaveFileCommand.cs:line 68 at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated) at System.Windows.Controls.Primitives.ButtonBase.OnClick() at System.Windows.Controls.Button.OnClick() at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e) at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e) at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent) at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e) at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args) at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted) at System.Windows.Input.InputManager.ProcessStagingArea() at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input) at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport) at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel) at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler) at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam) at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at FsDocumentationBuilder.App.Main() in D:\Users\dcveeneman\Documents\Visual Studio 2010\Projects\FsDocumentationBuilder\FsDocumentationBuilder\obj\x86\Debug\App.g.cs:line 50 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.Data.EntityCommandCompilationException Message=An error occurred while preparing the command definition. See the inner exception for details. Source=System.Data.Entity StackTrace: at System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree) at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(UpdateTranslator translator, Dictionary`2 identifierValues) at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator translator, EntityConnection connection, Dictionary`2 identifierValues, List`1 generatedValues) at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter) InnerException: System.NotSupportedException Message=Server-generated keys and server-generated values are not supported by SQL Server Compact. Source=System.Data.SqlServerCe.Entity StackTrace: at System.Data.SqlServerCe.SqlGen.DmlSqlGenerator.GenerateReturningSql(StringBuilder commandText, DbModificationCommandTree tree, ExpressionTranslator translator, DbExpression returning) at System.Data.SqlServerCe.SqlGen.DmlSqlGenerator.GenerateInsertSql(DbInsertCommandTree tree, List`1& parameters, Boolean isLocalProvider) at System.Data.SqlServerCe.SqlGen.SqlGenerator.GenerateSql(DbCommandTree tree, List`1& parameters, CommandType& commandType, Boolean isLocalProvider) at System.Data.SqlServerCe.SqlCeProviderServices.CreateCommand(DbProviderManifest providerManifest, DbCommandTree commandTree) at System.Data.SqlServerCe.SqlCeProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree) at System.Data.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree commandTree) at System.Data.Common.DbProviderServices.CreateCommand(DbCommandTree commandTree) at System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree) InnerException:

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  • Problem upgrading kernel on debian 3.1

    - by exhuma
    Hi, I have a quite old box in a remote server farm. So I have no direct access. Only remote SSH (and via SSH to a serial console). I haven't updated this box in ages. Now, whenever I want to install a new package, a dependency to glibc appears. Unfortunately, the install of glibc depends on a 2.6 kernel and I am running a venerable 2.4 kernel (one more reason to upgrade). The problem is, that the install of a new kernel has an indirect (over locales) dependency to glibc. So, to install glibc, I need a new kernel. For a new kernel, I need to upgrade glibc. Essentially I am blocked. What's the best way to proceed considering I have no "hardware" access? Here's a quick transcript of the upgrade process: [green:~]% sudo aptitude install linux-image-686 Reading Package Lists... Done Building Dependency Tree Reading extended state information Initializing package states... Done Reading task descriptions... Done The following packages are unused and will be REMOVED: gcc-4.3-base The following NEW packages will be automatically installed: dash libc6-i686 libparse-recdescent-perl linux-image-2.6-686 linux-image-2.6.18-6-686 module-init-tools yaird The following packages have been kept back: adduser apache2 apache2-mpm-prefork apache2-utils apache2.2-common apt apt-utils aptitude autoconf autotools-dev awstats base-files base-passwd [...snip...] util-linux vacation vim vim-common wamerican wbritish wget whiptail whois wwwconfig-common zlib1g The following NEW packages will be installed: dash libc6-i686 libparse-recdescent-perl linux-image-2.6-686 linux-image-2.6.18-6-686 linux-image-686 module-init-tools yaird The following packages will be upgraded: hotplug libc6 2 packages upgraded, 8 newly installed, 1 to remove and 277 not upgraded. Need to get 0B/22.7MB of archives. After unpacking 52.1MB will be used. Do you want to continue? [Y/n/?] Writing extended state information... Done Preconfiguring packages ... (Reading database ... 34065 files and directories currently installed.) Preparing to replace libc6 2.3.6.ds1-13 (using .../libc6_2.7-18lenny2_i386.deb) ... Checking for services that may need to be restarted... Checking init scripts... WARNING: init script for postgresql not found. [ --- libc6 config screen appears here --- ] WARNING: POSIX threads library NPTL requires kernel version 2.6.8 or later. If you use a kernel 2.4, please upgrade it before installing glibc. The installation of a 2.6 kernel _could_ ask you to install a new libc first, this is NOT a bug, and should *NOT* be reported. In that case, please add etch sources to your /etc/apt/sources.list and run: apt-get install -t etch linux-image-2.6 Then reboot into this new kernel, and proceed with your upgrade dpkg: error processing /var/cache/apt/archives/libc6_2.7-18lenny2_i386.deb (--unpack): subprocess pre-installation script returned error exit status 1 Errors were encountered while processing: /var/cache/apt/archives/libc6_2.7-18lenny2_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1) Ack! Something bad happened while installing packages. Trying to recover: dpkg: dependency problems prevent configuration of locales: locales depends on glibc-2.7-1; however: Package glibc-2.7-1 is not installed. dpkg: error processing locales (--configure): dependency problems - leaving unconfigured Errors were encountered while processing: locales Reading Package Lists... Done Building Dependency Tree Reading extended state information Initializing package states... Done Reading task descriptions... Done Now, if I follow the instrunctions as promted I get the following. Note that I am using aptitude instead of apt-get to benefit from the better dependency tracking. I did try with apt-get first. But that let me to the same problem. [green:~]% sudo aptitude install -t etch linux-image-2.6.26-2-686 Reading Package Lists... Done Building Dependency Tree Reading extended state information Initializing package states... Done Reading task descriptions... Done E: Unable to correct problems, you have held broken packages. E: Unable to correct dependencies, some packages cannot be installed E: Unable to resolve some dependencies! Some packages had unmet dependencies. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following packages have unmet dependencies: linux-image-2.6.26-2-686: Depends: initramfs-tools (>= 0.55) but it is not installable or yaird (>= 0.0.13) but it is not installable or linux-initramfs-tool which is a virtual package. Any ideas?

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  • Why does my performance slow to a crawl I move methods into a base class?

    - by Juliet
    I'm writing different implementations of immutable binary trees in C#, and I wanted my trees to inherit some common methods from a base class. However, I find. I have lots of binary tree data structures to implement, and I wanted move some common methods into in a base binary tree class. Unfortunately, classes which derive from the base class are abysmally slow. Non-derived classes perform adequately. Here are two nearly identical implementations of an AVL tree to demonstrate: AvlTree: http://pastebin.com/V4WWUAyT DerivedAvlTree: http://pastebin.com/PussQDmN The two trees have the exact same code, but I've moved the DerivedAvlTree.Insert method in base class. Here's a test app: using System; using System.Collections.Generic; using System.Diagnostics; using System.Linq; using Juliet.Collections.Immutable; namespace ConsoleApplication1 { class Program { const int VALUE_COUNT = 5000; static void Main(string[] args) { var avlTreeTimes = TimeIt(TestAvlTree); var derivedAvlTreeTimes = TimeIt(TestDerivedAvlTree); Console.WriteLine("avlTreeTimes: {0}, derivedAvlTreeTimes: {1}", avlTreeTimes, derivedAvlTreeTimes); } static double TimeIt(Func<int, int> f) { var seeds = new int[] { 314159265, 271828183, 231406926, 141421356, 161803399, 266514414, 15485867, 122949829, 198491329, 42 }; var times = new List<double>(); foreach (int seed in seeds) { var sw = Stopwatch.StartNew(); f(seed); sw.Stop(); times.Add(sw.Elapsed.TotalMilliseconds); } // throwing away top and bottom results times.Sort(); times.RemoveAt(0); times.RemoveAt(times.Count - 1); return times.Average(); } static int TestAvlTree(int seed) { var rnd = new System.Random(seed); var avlTree = AvlTree<double>.Create((x, y) => x.CompareTo(y)); for (int i = 0; i < VALUE_COUNT; i++) { avlTree = avlTree.Insert(rnd.NextDouble()); } return avlTree.Count; } static int TestDerivedAvlTree(int seed) { var rnd = new System.Random(seed); var avlTree2 = DerivedAvlTree<double>.Create((x, y) => x.CompareTo(y)); for (int i = 0; i < VALUE_COUNT; i++) { avlTree2 = avlTree2.Insert(rnd.NextDouble()); } return avlTree2.Count; } } } AvlTree: inserts 5000 items in 121 ms DerivedAvlTree: inserts 5000 items in 2182 ms My profiler indicates that the program spends an inordinate amount of time in BaseBinaryTree.Insert. Anyone whose interested can see the EQATEC log file I've created with the code above (you'll need EQATEC profiler to make sense of file). I really want to use a common base class for all of my binary trees, but I can't do that if performance will suffer. What causes my DerivedAvlTree to perform so badly, and what can I do to fix it?

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  • ASP.NET MVC Paging/Sorting/Filtering a list using ModelMetadata

    - by rajbk
    This post looks at how to control paging, sorting and filtering when displaying a list of data by specifying attributes in your Model using the ASP.NET MVC framework and the excellent MVCContrib library. It also shows how to hide/show columns and control the formatting of data using attributes.  This uses the Northwind database. A sample project is attached at the end of this post. Let’s start by looking at a class called ProductViewModel. The properties in the class are decorated with attributes. The OrderBy attribute tells the system that the Model can be sorted using that property. The SearchFilter attribute tells the system that filtering is allowed on that property. Filtering type is set by the  FilterType enum which currently supports Equals and Contains. The ScaffoldColumn property specifies if a column is hidden or not The DisplayFormat specifies how the data is formatted. public class ProductViewModel { [OrderBy(IsDefault = true)] [ScaffoldColumn(false)] public int? ProductID { get; set; }   [SearchFilter(FilterType.Contains)] [OrderBy] [DisplayName("Product Name")] public string ProductName { get; set; }   [OrderBy] [DisplayName("Unit Price")] [DisplayFormat(DataFormatString = "{0:c}")] public System.Nullable<decimal> UnitPrice { get; set; }   [DisplayName("Category Name")] public string CategoryName { get; set; }   [SearchFilter] [ScaffoldColumn(false)] public int? CategoryID { get; set; }   [SearchFilter] [ScaffoldColumn(false)] public int? SupplierID { get; set; }   [OrderBy] public bool Discontinued { get; set; } } Before we explore the code further, lets look at the UI.  The UI has a section for filtering the data. The column headers with links are sortable. Paging is also supported with the help of a pager row. The pager is rendered using the MVCContrib Pager component. The data is displayed using a customized version of the MVCContrib Grid component. The customization was done in order for the Grid to be aware of the attributes mentioned above. Now, let’s look at what happens when we perform actions on this page. The diagram below shows the process: The form on the page has its method set to “GET” therefore we see all the parameters in the query string. The query string is shown in blue above. This query gets routed to an action called Index with parameters of type ProductViewModel and PageSortOptions. The parameters in the query string get mapped to the input parameters using model binding. The ProductView object created has the information needed to filter data while the PageAndSorting object is used for paging and sorting the data. The last block in the figure above shows how the filtered and paged list is created. We receive a product list from our product repository (which is of type IQueryable) and first filter it by calliing the AsFiltered extension method passing in the productFilters object and then call the AsPagination extension method passing in the pageSort object. The AsFiltered extension method looks at the type of the filter instance passed in. It skips properties in the instance that do not have the SearchFilter attribute. For properties that have the SearchFilter attribute, it adds filter expression trees to filter against the IQueryable data. The AsPagination extension method looks at the type of the IQueryable and ensures that the column being sorted on has the OrderBy attribute. If it does not find one, it looks for the default sort field [OrderBy(IsDefault = true)]. It is required that at least one attribute in your model has the [OrderBy(IsDefault = true)]. This because a person could be performing paging without specifying an order by column. As you may recall the LINQ Skip method now requires that you call an OrderBy method before it. Therefore we need a default order by column to perform paging. The extension method adds a order expressoin tree to the IQueryable and calls the MVCContrib AsPagination extension method to page the data. Implementation Notes Auto Postback The search filter region auto performs a get request anytime the dropdown selection is changed. This is implemented using the following jQuery snippet $(document).ready(function () { $("#productSearch").change(function () { this.submit(); }); }); Strongly Typed View The code used in the Action method is shown below: public ActionResult Index(ProductViewModel productFilters, PageSortOptions pageSortOptions) { var productPagedList = productRepository.GetProductsProjected().AsFiltered(productFilters).AsPagination(pageSortOptions);   var productViewFilterContainer = new ProductViewFilterContainer(); productViewFilterContainer.Fill(productFilters.CategoryID, productFilters.SupplierID, productFilters.ProductName);   var gridSortOptions = new GridSortOptions { Column = pageSortOptions.Column, Direction = pageSortOptions.Direction };   var productListContainer = new ProductListContainerModel { ProductPagedList = productPagedList, ProductViewFilterContainer = productViewFilterContainer, GridSortOptions = gridSortOptions };   return View(productListContainer); } As you see above, the object that is returned to the view is of type ProductListContainerModel. This contains all the information need for the view to render the Search filter section (including dropdowns),  the Html.Pager (MVCContrib) and the Html.Grid (from MVCContrib). It also stores the state of the search filters so that they can recreate themselves when the page reloads (Viewstate, I miss you! :0)  The class diagram for the container class is shown below.   Custom MVCContrib Grid The MVCContrib grid default behavior was overridden so that it would auto generate the columns and format the columns based on the metadata and also make it aware of our custom attributes (see MetaDataGridModel in the sample code). The Grid ensures that the ShowForDisplay on the column is set to true This can also be set by the ScaffoldColumn attribute ref: http://bradwilson.typepad.com/blog/2009/10/aspnet-mvc-2-templates-part-2-modelmetadata.html) Column headers are set using the DisplayName attribute Column sorting is set using the OrderBy attribute. The data is formatted using the DisplayFormat attribute. Generic Extension methods for Sorting and Filtering The extension method AsFiltered takes in an IQueryable<T> and uses expression trees to query against the IQueryable data. The query is constructed using the Model metadata and the properties of the T filter (productFilters in our case). Properties in the Model that do not have the SearchFilter attribute are skipped when creating the filter expression tree.  It returns an IQueryable<T>. The extension method AsPagination takes in an IQuerable<T> and first ensures that the column being sorted on has the OrderBy attribute. If not, we look for the default OrderBy column ([OrderBy(IsDefault = true)]). We then build an expression tree to sort on this column. We finally hand off the call to the MVCContrib AsPagination which returns an IPagination<T>. This type as you can see in the class diagram above is passed to the view and used by the MVCContrib Grid and Pager components. Custom Provider To get the system to recognize our custom attributes, we create our MetadataProvider as mentioned in this article (http://bradwilson.typepad.com/blog/2010/01/why-you-dont-need-modelmetadataattributes.html) protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName) { ModelMetadata metadata = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);   SearchFilterAttribute searchFilterAttribute = attributes.OfType<SearchFilterAttribute>().FirstOrDefault(); if (searchFilterAttribute != null) { metadata.AdditionalValues.Add(Globals.SearchFilterAttributeKey, searchFilterAttribute); }   OrderByAttribute orderByAttribute = attributes.OfType<OrderByAttribute>().FirstOrDefault(); if (orderByAttribute != null) { metadata.AdditionalValues.Add(Globals.OrderByAttributeKey, orderByAttribute); }   return metadata; } We register our MetadataProvider in Global.asax.cs. protected void Application_Start() { AreaRegistration.RegisterAllAreas();   RegisterRoutes(RouteTable.Routes);   ModelMetadataProviders.Current = new MvcFlan.QueryModelMetaDataProvider(); } Bugs, Comments and Suggestions are welcome! You can download the sample code below. This code is purely experimental. Use at your own risk. Download Sample Code (VS 2010 RTM) MVCNorthwindSales.zip

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  • CodePlex Daily Summary for Monday, March 15, 2010

    CodePlex Daily Summary for Monday, March 15, 2010New ProjectsAT Accounts: AT Accounts helps developers to intergrate accounting functionality in their applications. It has both the WPF userinterface and SilverlightChild page list(for dnn4/5): A free module which can display sub pages list for a selected tab. It is template based and support options like Recursive/Child tab prefix/link...dashCommerce: dashCommerce is the leading ASP.NET e-commerce platform.Fire Utilities: My Development Utiltites and base classes: New Zealand Bank Account ValidatorFlyCatch (Bugtracking System): A simple webbased Bugtracking System.fracback: Fractal feedback concepts, based on video feedbackftc3650: code for ftc 3650Google AJAX Search Services for jQuery: This plug-in encapsulates part of the Google AJAX Search API to streamline the process of Google Search integration.Little Black Book DB: This is the Database for the following Projects: SQL Azure PHP Connection SQL Azure Ruby Connection SQL Azure Python Connection SQL Azure .NE...MediaCommMVC: MediaCommMVC is a community platform focusing on photos, videos and discussions. It's based on ASP.NET MVC and uses (fluent) nhibernate, jquery an...Miracle OS: The Miracle OS is an OS from Fox. We work on it, but it isn't ready. Do you want help us? Please send a mail to victor@fox.fi.stMultiwfn: (1)Plotting various graph(filled color/contour/relief map...) (2)Generate Cube file (3)Manipulate & analyze wavefunction Supportting lots of proper...MySpace DataRelay: Data Relay is the foundation of MySpace's middle tier. At its heart, it is a messaging system for relaying information both between clients and ser...NinjaCMS: Ninja CMS is an asp.net based content management system which provides a designer friendly, developer friendly interface to work with. It's flexibl...open gaze and mouse analyzer: Ogama allows recording and analyzing eye- and mouse-tracking data from slideshow eyetracking experiments in parallel. It´s developed in C#.NET and ...Özkasoft.Net | E-Commerce: Özkasoft's E-Commerce ProjectProfiCV: Profi CVpyTarget: Implement a powerful iscsi target in python, and easily use under most popular systems. It also includes the following features: multi-target, mult...SharePoint Platform Extensions: SharePoint Platform Extensions by Espora. Sorting Algorithm Visualization: Sorting Algorithm Visualization Displays Bead Sort, Binary Tree Sort, Bubble Sort, Bucket Sort, Cocktail Sort, Counting Sort, Gnome Sort, In Place ...Specify: A framework for creating executable specifications in .NET. Spell Corrector: A spell corrector that uses Bayes algorithm and BK (Burkhard-Keller) tree.SQL Azure Ruby Connection: This is a demo to show how to connect to SQL Azure with Ruby on Rails.uManage - AD Self-Service Portal: uManage is an Active Directory Self-Service Portal as well as Help Desk web application designed for use on intranet systems. It allows users to u...Winforms Rounded Group Box Control: Rounded Group Box - A Grouping control with Rounded Corners, Gradients, and Drop ShadowWizard Engine: Host application agnostic wizard engine platform, that allows you to fluently define complex conditional flows and provides means for execution of ...WS-Transfer based File Upload: WS-Transer based upload of large files in multiple partsXAMLStylePad: XAMLStylePad - is a simple in use styles and templates XAML-editor. It designed for comfortable coding in XAML with real-time preview result on aut...Your Twitt Engine: Ovo je aplikacija za sve ljude koji su na svom radnom mjestu pod prismotrom poslodavca ili sefa, koji kontroliraju njihov monitor. Tako uz ovu apl...New ReleasesAmiBroker Plug-ins with C#. A non official AmiBroker Plug-in SDK: AniBroker Plug-in SDK v0.0.5: Removed dependency on .NET 4.0, now it works fine with .NET 2.0BeerMath.net: 0.1: Version 0.1Initial set of calculations supported: IBUs Color ABV/ABWChild page list(for dnn4/5): Child Page List 2.6: Source code is also include in module package.dashCommerce: dashCommerce Releases: You can download both Source and WebReady packages at http://www.dashcommerce.org. If you wish to submit patches, then use the Source Code tab her...ExcelDna: ExcelDna Version 0.23: ExcelDna Version 0.23 2010/03/14 - Packing and other features This release adds a number of features to ExcelDna: Add ExplicitExports attribute to ...Family Tree Analyzer: Version 1.0.7.1: Version 1.0.7.0 Update Census form to show family totals Fix England and Wales Lost Cousins reports to be England OR Wales Problems with Gedcom in...Foursquare BlogEngine Widget: foursquare widget for BlogEngine.NET Version 0.2: To see the changes which have been made, visit http://philippkueng.ch/post/Foursquare-BlogEngineNET-Widget-Version-02.aspx For installation instruc...GLB Virtual Player Builder: 0.4.0 Official Archetypes Release: Updated for new archetypes. The builder still includes the old player formats, and you can still import your old players' builds. Please PM me an...Home Access Plus+: v3.1.4.0: Version 3.1.3.1 Release Change Log: Added Breadcrumbs to My Computer File Changes: ~/bin/CHS Extranet.dll ~/bin/CHS Extranet.pdb ~/images/arro...Little Black Book DB: Little Black Book R1: This is the first release of the Little black book presentation I presented at Confoo. I decided to package the Database along with the Windows Az...mite.net - .NET API for mite: Version 1.2.1: Added Support for budget type Modified TimerMapper to return timers Fixed Encoding issue in xml conversionMultiwfn: multiwfn1.0: multiwfn1.0Multiwfn: multiwfn1.0_source: multiwfn1.0_sourceMultiwfn: multiwfn1.1: multiwfn1.1Multiwfn: multiwfn1.1_source: multiwfn1.1_sourceMultiwfn: multiwfn1.2: 1.2 2010-FEB-9 *加入了对10f型轨道的支持。 *新支持非限制性Post-HF波函数用以计算自旋密度。 *新增加直接读入高斯03/09的fch文件的支持,可以观看NBO轨道,详见readme实例4.10。 *绘制平面图时允许通过输入三个点坐标定义平面,允许自定义平面的原点与平移向...Multiwfn: multiwfn1.2_source: Include all the file that needed by compilation in CVF6.5PowerShell Community Extensions: 2.0 Beta 2: Release NotesThis is a pretty close to final release. We have eliminated all of the names that ran afound of the module loading mechanism which me...pyTarget: pyTarget.binary-for-windows-x86.rar: pyTarget.binary-for-windows-x86.rarpyTarget: pyTarget.src.tar.bz2: pyTarget.src.tar.bz2RedBulb for XNA Framework: RedBulbConsole (Console, Menu and TrackHUD Sample): http://bayimg.com/image/jalhmaacd.jpgScrum Sprint Monitor: 1.0.0.45262 (.NET 4.0 RC): Tested against TFS 2010 RC. For the .NET 3.5 SP1 platform, use the .NET 3.5 SP1 download. What is new in this release? Major performance increase ...sELedit: sELedit v1.1: Removed: Clone and Delete Button Added: Context Menu to Item List Added: Clone and Delete button to Context Menu Added: Export / Import Item ...Sorting Algorithm Visualization: Beta 1: Sorting Algorithm VisualizationSpecify: Version 1.0: Version 1.0Spell Corrector: Spell Corrector 0.1: A basic version that supports basic functionality.Spell Corrector: Spell Corrector 0.1 Source Code: Source code of version 0.1Spiral Architecture Driven Development (SADD): SADD v.0.9: Pre-final release with the NEW materials now all in English ! The Final release is coming soon. After guest column for SADD publication in MS Ar...Spiral Architecture Driven Development (SADD) for Russian: SADD v.0.9: Pre-final release with the NEW materials now all in English ! The Final release is coming soon. After guest column for SADD publication in MS Ar...SQL Azure Ruby Connection: Little Black Book Ruby R1: This is the Ruby Demo that I demostrated at Confoo. Special Thanks to Tony Thompson for putting this demo together. To check out Tony's Portfolio ...The Scrum Factory: The Scrum Factory Server - V1a: This is the newest version of the server. Some minor bugs from version v1 were fixed, and some slighted changed were made some database views.twNowplaying: twNowplaying 1.0.0.4: Please note that the user has to press the Twitter logo to log in the first time the application is started.uManage - AD Self-Service Portal: uManage - v1.0 (.NET 4.0 RC): Initial Release of uManage. NOTE: Designed for ASP.NET and .NET 4.0 RC ONLY! This is the initial release of uManage and covers the first phase of ...Virtu: Virtu 0.8: Source Requirements.NET Framework 3.5 with Service Pack 1 Visual Studio 2008 with Service Pack 1, or Visual C# 2008 Express Edition with Service Pa...Visual Studio DSite: Speech Synthesizer (Text to Speech) in Visual C++: A very simple text to speech program written in visual c 2008.White Tiger: 0.0.4.0: *now you can disable the file security checks *winforms aplications created to manage tablesWinforms Rounded Group Box Control: Release 1.0: To use this control simply add the class to your project and compile it. It will then show up in the projects components section in the toolbox. ...WS-Transfer based File Upload: 0.5: Implements the binary file transfer mechanism onlyXsltDb - DotNetNuke XSLT module: 01.00.89: Super modules configuration names. 16767 - Fixed more bug fixes...Yakiimo3D: DirectX11 Rheinhard Tonemapping Source and Binary: DirectX11 Rheinhard tonemapping source and binary.Your Twitt Engine: test: Slobodno probajte sa vasim twitter korisničkim računomMost Popular ProjectsMetaSharpWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitASP.NET Ajax LibraryWindows Presentation Foundation (WPF)ASP.NETLiveUpload to FacebookMost Active ProjectsLINQ to TwitterRawrN2 CMSBlogEngine.NETpatterns & practices – Enterprise LibrarySharePoint Team-MailerjQuery Library for SharePoint Web ServicesCaliburn: An Application Framework for WPF and SilverlightFarseer Physics EngineCalcium: A modular application toolset leveraging Prism

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  • jQuery Treeview – Expand and Collapse All Without the TreeControl

    - by Ben Griswold
    The jQuery Treeview Plugin provides collapse all, expand all and toggle all support with very little effort on your part. Simply add a treecontrol with three links, and the treeview, to your page…   <div id="treecontrol">     <a title="Collapse the entire tree below" href="#"><img src="../images/minus.gif" /> Collapse All</a>     <a title="Expand the entire tree below" href="#"><img src="../images/plus.gif" /> Expand All</a>     <a title="Toggle the tree below, opening closed branches, closing open branches" href="#">Toggle All</a> </div> <ul id="treeview" class="treeview-black">     <li>Item 1</li>     <li>         <span>Item 2</span>         <ul>             <li>                 <span>Item 2.1</span>                   <ul>                     <li>Item 2.1.1</li>                     <li>Item 2.1.2</li>                 </ul>             </li>             <li>Item 2.2</li>             <li class="closed">                   <span>Item 2.3 (closed at start)</span>                 <ul>                     <li>Item 2.3.1</li>                     <li>Item 2.3.2</li>                 </ul>             </li>         </ul>     </li> </ul> …and then associate the control to the treeview when defining the treeview settings. $("#treeview").treeview({     control: "#treecontrol",     persist: "cookie",     cookieId: "treeview-black" }); It really couldn’t be easier and it works great! But the plugin doesn’t offer a lot of flexibility when it comes to layout.  For example, the plugin assumes your treecontrol will include links.  If you want buttons or images or whatever, you are out of luck.  The plugin also assumes a set number of links and the collapse all handler is associated with the first link inside of the treecontrol, a:eq(0), the expand all handler is associated with the second link and so on.  So you really can’t incorporate the toggle all link by itself unless you manually hide the other options. Which brings me to the point of this post – making the collapse/expand/toggle layout more flexible without modifying the plugin’s source code. We will continue to use the treecontrol actions but we’re not going to use them directly. In fact, our custom collapse, expand and toggle links will trigger the actions for us.  So, hide the treecontrol links and associate the treecontrol click events with the click events of other controls.  Finally, render the treeview with the same setting definitions as usual. $(document).ready(function() {     // The plugin shows the treecontrol after the     // collapse, expand and toggle events are hooked up     // Just hide the links.     $('#treecontrol a').hide();       // On click of your custom links, button, etc     // Trigger the appropriate treecontrol click     $('#expandAll').click(function() {                 $('#treecontrol a:eq(1)').click();         });          $('#collapseAll').click(function() {         $('#treecontrol a:eq(0)').click();             });       // Render the treeview per usual.         $("#treeview").treeview({         control: "#treecontrol",         persist: "cookie",         cookieId: "treeview-black"     }); }); Since I’m not using the treecontrol directly, I move it to the bottom of the page but it doesn’t really matter where the treecontrol goes. <div>     <a id="collapseAll" href="#">Collapse All Outside of TreeControl</a> </div>   <ul id="treeview" class="treeview-black">     <li>Item 1</li>     <li>         <span>Item 2</span>         <ul>             <li>                 <span>Item 2.1</span>                 <ul>                     <li>Item 2.1.1</li>                     <li>Item 2.1.2</li>                 </ul>             </li>             <li>Item 2.2</li>             <li class="closed">                 <span>Item 2.3 (closed at start)</span>                 <ul>                     <li>Item 2.3.1</li>                     <li>Item 2.3.2</li>                 </ul>             </li>         </ul>     </li> </ul>   <div>     <input type="button" id="expandAll" value="Expand All Outside of TreeControl"/> </div>   <div id="treecontrol">     <a href="#"></a><a href="#"></a><a href="#"></a> </div> The above jQuery and Html snippets generate the following ugly output which shows the separated collapse/expand elements. If you want the toggle all option, I bet you can figure out how to put it in place.  I’ve made the source available below if you’re interested. Download jQuery Treeview Expand and Collapse Super Code

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  • Project Navigation and File Nesting in ASP.NET MVC Projects

    - by Rick Strahl
    More and more I’m finding myself getting lost in the files in some of my larger Web projects. There’s so much freaking content to deal with – HTML Views, several derived CSS pages, page level CSS, script libraries, application wide scripts and page specific script files etc. etc. Thankfully I use Resharper and the Ctrl-T Go to Anything which autocompletes you to any file, type, member rapidly. Awesome except when I forget – or when I’m not quite sure of the name of what I’m looking for. Project navigation is still important. Sometimes while working on a project I seem to have 30 or more files open and trying to locate another new file to open in the solution often ends up being a mental exercise – “where did I put that thing?” It’s those little hesitations that tend to get in the way of workflow frequently. To make things worse most NuGet packages for client side frameworks and scripts, dump stuff into folders that I generally don’t use. I’ve never been a fan of the ‘Content’ folder in MVC which is just an empty layer that doesn’t serve much of a purpose. It’s usually the first thing I nuke in every MVC project. To me the project root is where the actual content for a site goes – is there really a need to add another folder to force another path into every resource you use? It’s ugly and also inefficient as it adds additional bytes to every resource link you embed into a page. Alternatives I’ve been playing around with different folder layouts recently and found that moving my cheese around has actually made project navigation much easier. In this post I show a couple of things I’ve found useful and maybe you find some of these useful as well or at least get some ideas what can be changed to provide better project flow. The first thing I’ve been doing is add a root Code folder and putting all server code into that. I’m a big fan of treating the Web project root folder as my Web root folder so all content comes from the root without unneeded nesting like the Content folder. By moving all server code out of the root tree (except for Code) the root tree becomes a lot cleaner immediately as you remove Controllers, App_Start, Models etc. and move them underneath Code. Yes this adds another folder level for server code, but it leaves only code related things in one place that’s easier to jump back and forth in. Additionally I find myself doing a lot less with server side code these days, more with client side code so I want the server code separated from that. The root folder itself then serves as the root content folder. Specifically I have the Views folder below it, as well as the Css and Scripts folders which serve to hold only common libraries and global CSS and Scripts code. These days of building SPA style application, I also tend to have an App folder there where I keep my application specific JavaScript files, as well as HTML View templates for client SPA apps like Angular. Here’s an example of what this looks like in a relatively small project: The goal is to keep things that are related together, so I don’t end up jumping around so much in the solution to get to specific project items. The Code folder may irk some of you and hark back to the days of the App_Code folder in non Web-Application projects, but these days I find myself messing with a lot less server side code and much more with client side files – HTML, CSS and JavaScript. Generally I work on a single controller at a time – once that’s open it’s open that’s typically the only server code I work with regularily. Business logic lives in another project altogether, so other than the controller and maybe ViewModels there’s not a lot of code being accessed in the Code folder. So throwing that off the root and isolating seems like an easy win. Nesting Page specific content In a lot of my existing applications that are pure server side MVC application perhaps with some JavaScript associated with them , I tend to have page level javascript and css files. For these types of pages I actually prefer the local files stored in the same folder as the parent view. So typically I have a .css and .js files with the same name as the view in the same folder. This looks something like this: In order for this to work you have to also make a configuration change inside of the /Views/web.config file, as the Views folder is blocked with the BlockViewHandler that prohibits access to content from that folder. It’s easy to fix by changing the path from * to *.cshtml or *.vbhtml so that view retrieval is blocked:<system.webServer> <handlers> <remove name="BlockViewHandler"/> <add name="BlockViewHandler" path="*.cshtml" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" /> </handlers> </system.webServer> With this in place, from inside of your Views you can then reference those same resources like this:<link href="~/Views/Admin/QuizPrognosisItems.css" rel="stylesheet" /> and<script src="~/Views/Admin/QuizPrognosisItems.js"></script> which works fine. JavaScript and CSS files in the Views folder deploy just like the .cshtml files do and can be referenced from this folder as well. Making this happen is not really as straightforward as it should be with just Visual Studio unfortunately, as there’s no easy way to get the file nesting from the VS IDE directly (you have to modify the .csproj file). However, Mads Kristensen has a nice Visual Studio Add-in that provides file nesting via a short cut menu option. Using this you can select each of the ‘child’ files and then nest them under a parent file. In the case above I select the .js and .css files and nest them underneath the .cshtml view. I was even toying with the idea of throwing the controller.cs files into the Views folder, but that’s maybe going a little too far :-) It would work however as Visual Studio doesn’t publish .cs files and the compiler doesn’t care where the files live. There are lots of options and if you think that would make life easier it’s another option to help group related things together. Are there any downside to this? Possibly – if you’re using automated minification/packaging tools like ASP.NET Bundling or Grunt/Gulp with Uglify, it becomes a little harder to group script and css files for minification as you may end up looking in multiple folders instead of a single folder. But – again that’s a one time configuration step that’s easily handled and much less intrusive then constantly having to search for files in your project. Client Side Folders The particular project shown above in the screen shots above is a traditional server side ASP.NET MVC application with most content rendered into server side Razor pages. There’s a fair amount of client side stuff happening on these pages as well – specifically several of these pages are self contained single page Angular applications that deal with 1 or maybe 2 separate views and the layout I’ve shown above really focuses on the server side aspect where there are Razor views with related script and css resources. For applications that are more client centric and have a lot more script and HTML template based content I tend to use the same layout for the server components, but the client side code can often be broken out differently. In SPA type applications I tend to follow the App folder approach where all the application pieces that make the SPA applications end up below the App folder. Here’s what that looks like for me – here this is an AngularJs project: In this case the App folder holds both the application specific js files, and the partial HTML views that get loaded into this single SPA page application. In this particular Angular SPA application that has controllers linked to particular partial views, I prefer to keep the script files that are associated with the views – Angular Js Controllers in this case – with the actual partials. Again I like the proximity of the view with the main code associated with the view, because 90% of the UI application code that gets written is handled between these two files. This approach works well, but only if controllers are fairly closely aligned with the partials. If you have many smaller sub-controllers or lots of directives where the alignment between views and code is more segmented this approach starts falling apart and you’ll probably be better off with separate folders in js folder. Following Angular conventions you’d have controllers/directives/services etc. folders. Please note that I’m not saying any of these ways are right or wrong  – this is just what has worked for me and why! Skipping Project Navigation altogether with Resharper I’ve talked a bit about project navigation in the project tree, which is a common way to navigate and which we all use at least some of the time, but if you use a tool like Resharper – which has Ctrl-T to jump to anything, you can quickly navigate with a shortcut key and autocomplete search. Here’s what Resharper’s jump to anything looks like: Resharper’s Goto Anything box lets you type and quick search over files, classes and members of the entire solution which is a very fast and powerful way to find what you’re looking for in your project, by passing the solution explorer altogether. As long as you remember to use (which I sometimes don’t) and you know what you’re looking for it’s by far the quickest way to find things in a project. It’s a shame that this sort of a simple search interface isn’t part of the native Visual Studio IDE. Work how you like to work Ultimately it all comes down to workflow and how you like to work, and what makes *you* more productive. Following pre-defined patterns is great for consistency, as long as they don’t get in the way you work. A lot of the default folder structures in Visual Studio for ASP.NET MVC were defined when things were done differently. These days we’re dealing with a lot more diverse project content than when ASP.NET MVC was originally introduced and project organization definitely is something that can get in the way if it doesn’t fit your workflow. So take a look and see what works well and what might benefit from organizing files differently. As so many things with ASP.NET, as things evolve and tend to get more complex I’ve found that I end up fighting some of the conventions. The good news is that you don’t have to follow the conventions and you have the freedom to do just about anything that works for you. Even though what I’ve shown here diverges from conventions, I don’t think anybody would stumble over these relatively minor changes and not immediately figure out where things live, even in larger projects. But nevertheless think long and hard before breaking those conventions – if there isn’t a good reason to break them or the changes don’t provide improved workflow then it’s not worth it. Break the rules, but only if there’s a quantifiable benefit. You may not agree with how I’ve chosen to divert from the standard project structures in this article, but maybe it gives you some ideas of how you can mix things up to make your existing project flow a little nicer and make it easier to navigate for your environment. © Rick Strahl, West Wind Technologies, 2005-2014Posted in ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (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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  • Hello Operator, My Switch Is Bored

    - by Paul White
    This is a post for T-SQL Tuesday #43 hosted by my good friend Rob Farley. The topic this month is Plan Operators. I haven’t taken part in T-SQL Tuesday before, but I do like to write about execution plans, so this seemed like a good time to start. This post is in two parts. The first part is primarily an excuse to use a pretty bad play on words in the title of this blog post (if you’re too young to know what a telephone operator or a switchboard is, I hate you). The second part of the post looks at an invisible query plan operator (so to speak). 1. My Switch Is Bored Allow me to present the rare and interesting execution plan operator, Switch: Books Online has this to say about Switch: Following that description, I had a go at producing a Fast Forward Cursor plan that used the TOP operator, but had no luck. That may be due to my lack of skill with cursors, I’m not too sure. The only application of Switch in SQL Server 2012 that I am familiar with requires a local partitioned view: CREATE TABLE dbo.T1 (c1 int NOT NULL CHECK (c1 BETWEEN 00 AND 24)); CREATE TABLE dbo.T2 (c1 int NOT NULL CHECK (c1 BETWEEN 25 AND 49)); CREATE TABLE dbo.T3 (c1 int NOT NULL CHECK (c1 BETWEEN 50 AND 74)); CREATE TABLE dbo.T4 (c1 int NOT NULL CHECK (c1 BETWEEN 75 AND 99)); GO CREATE VIEW V1 AS SELECT c1 FROM dbo.T1 UNION ALL SELECT c1 FROM dbo.T2 UNION ALL SELECT c1 FROM dbo.T3 UNION ALL SELECT c1 FROM dbo.T4; Not only that, but it needs an updatable local partitioned view. We’ll need some primary keys to meet that requirement: ALTER TABLE dbo.T1 ADD CONSTRAINT PK_T1 PRIMARY KEY (c1);   ALTER TABLE dbo.T2 ADD CONSTRAINT PK_T2 PRIMARY KEY (c1);   ALTER TABLE dbo.T3 ADD CONSTRAINT PK_T3 PRIMARY KEY (c1);   ALTER TABLE dbo.T4 ADD CONSTRAINT PK_T4 PRIMARY KEY (c1); We also need an INSERT statement that references the view. Even more specifically, to see a Switch operator, we need to perform a single-row insert (multi-row inserts use a different plan shape): INSERT dbo.V1 (c1) VALUES (1); And now…the execution plan: The Constant Scan manufactures a single row with no columns. The Compute Scalar works out which partition of the view the new value should go in. The Assert checks that the computed partition number is not null (if it is, an error is returned). The Nested Loops Join executes exactly once, with the partition id as an outer reference (correlated parameter). The Switch operator checks the value of the parameter and executes the corresponding input only. If the partition id is 0, the uppermost Clustered Index Insert is executed, adding a row to table T1. If the partition id is 1, the next lower Clustered Index Insert is executed, adding a row to table T2…and so on. In case you were wondering, here’s a query and execution plan for a multi-row insert to the view: INSERT dbo.V1 (c1) VALUES (1), (2); Yuck! An Eager Table Spool and four Filters! I prefer the Switch plan. My guess is that almost all the old strategies that used a Switch operator have been replaced over time, using things like a regular Concatenation Union All combined with Start-Up Filters on its inputs. Other new (relative to the Switch operator) features like table partitioning have specific execution plan support that doesn’t need the Switch operator either. This feels like a bit of a shame, but perhaps it is just nostalgia on my part, it’s hard to know. Please do let me know if you encounter a query that can still use the Switch operator in 2012 – it must be very bored if this is the only possible modern usage! 2. Invisible Plan Operators The second part of this post uses an example based on a question Dave Ballantyne asked using the SQL Sentry Plan Explorer plan upload facility. If you haven’t tried that yet, make sure you’re on the latest version of the (free) Plan Explorer software, and then click the Post to SQLPerformance.com button. That will create a site question with the query plan attached (which can be anonymized if the plan contains sensitive information). Aaron Bertrand and I keep a close eye on questions there, so if you have ever wanted to ask a query plan question of either of us, that’s a good way to do it. The problem The issue I want to talk about revolves around a query issued against a calendar table. The script below creates a simplified version and adds 100 years of per-day information to it: USE tempdb; GO CREATE TABLE dbo.Calendar ( dt date NOT NULL, isWeekday bit NOT NULL, theYear smallint NOT NULL,   CONSTRAINT PK__dbo_Calendar_dt PRIMARY KEY CLUSTERED (dt) ); GO -- Monday is the first day of the week for me SET DATEFIRST 1;   -- Add 100 years of data INSERT dbo.Calendar WITH (TABLOCKX) (dt, isWeekday, theYear) SELECT CA.dt, isWeekday = CASE WHEN DATEPART(WEEKDAY, CA.dt) IN (6, 7) THEN 0 ELSE 1 END, theYear = YEAR(CA.dt) FROM Sandpit.dbo.Numbers AS N CROSS APPLY ( VALUES (DATEADD(DAY, N.n - 1, CONVERT(date, '01 Jan 2000', 113))) ) AS CA (dt) WHERE N.n BETWEEN 1 AND 36525; The following query counts the number of weekend days in 2013: SELECT Days = COUNT_BIG(*) FROM dbo.Calendar AS C WHERE theYear = 2013 AND isWeekday = 0; It returns the correct result (104) using the following execution plan: The query optimizer has managed to estimate the number of rows returned from the table exactly, based purely on the default statistics created separately on the two columns referenced in the query’s WHERE clause. (Well, almost exactly, the unrounded estimate is 104.289 rows.) There is already an invisible operator in this query plan – a Filter operator used to apply the WHERE clause predicates. We can see it by re-running the query with the enormously useful (but undocumented) trace flag 9130 enabled: Now we can see the full picture. The whole table is scanned, returning all 36,525 rows, before the Filter narrows that down to just the 104 we want. Without the trace flag, the Filter is incorporated in the Clustered Index Scan as a residual predicate. It is a little bit more efficient than using a separate operator, but residual predicates are still something you will want to avoid where possible. The estimates are still spot on though: Anyway, looking to improve the performance of this query, Dave added the following filtered index to the Calendar table: CREATE NONCLUSTERED INDEX Weekends ON dbo.Calendar(theYear) WHERE isWeekday = 0; The original query now produces a much more efficient plan: Unfortunately, the estimated number of rows produced by the seek is now wrong (365 instead of 104): What’s going on? The estimate was spot on before we added the index! Explanation You might want to grab a coffee for this bit. Using another trace flag or two (8606 and 8612) we can see that the cardinality estimates were exactly right initially: The highlighted information shows the initial cardinality estimates for the base table (36,525 rows), the result of applying the two relational selects in our WHERE clause (104 rows), and after performing the COUNT_BIG(*) group by aggregate (1 row). All of these are correct, but that was before cost-based optimization got involved :) Cost-based optimization When cost-based optimization starts up, the logical tree above is copied into a structure (the ‘memo’) that has one group per logical operation (roughly speaking). The logical read of the base table (LogOp_Get) ends up in group 7; the two predicates (LogOp_Select) end up in group 8 (with the details of the selections in subgroups 0-6). These two groups still have the correct cardinalities as trace flag 8608 output (initial memo contents) shows: During cost-based optimization, a rule called SelToIdxStrategy runs on group 8. It’s job is to match logical selections to indexable expressions (SARGs). It successfully matches the selections (theYear = 2013, is Weekday = 0) to the filtered index, and writes a new alternative into the memo structure. The new alternative is entered into group 8 as option 1 (option 0 was the original LogOp_Select): The new alternative is to do nothing (PhyOp_NOP = no operation), but to instead follow the new logical instructions listed below the NOP. The LogOp_GetIdx (full read of an index) goes into group 21, and the LogOp_SelectIdx (selection on an index) is placed in group 22, operating on the result of group 21. The definition of the comparison ‘the Year = 2013’ (ScaOp_Comp downwards) was already present in the memo starting at group 2, so no new memo groups are created for that. New Cardinality Estimates The new memo groups require two new cardinality estimates to be derived. First, LogOp_Idx (full read of the index) gets a predicted cardinality of 10,436. This number comes from the filtered index statistics: DBCC SHOW_STATISTICS (Calendar, Weekends) WITH STAT_HEADER; The second new cardinality derivation is for the LogOp_SelectIdx applying the predicate (theYear = 2013). To get a number for this, the cardinality estimator uses statistics for the column ‘theYear’, producing an estimate of 365 rows (there are 365 days in 2013!): DBCC SHOW_STATISTICS (Calendar, theYear) WITH HISTOGRAM; This is where the mistake happens. Cardinality estimation should have used the filtered index statistics here, to get an estimate of 104 rows: DBCC SHOW_STATISTICS (Calendar, Weekends) WITH HISTOGRAM; Unfortunately, the logic has lost sight of the link between the read of the filtered index (LogOp_GetIdx) in group 22, and the selection on that index (LogOp_SelectIdx) that it is deriving a cardinality estimate for, in group 21. The correct cardinality estimate (104 rows) is still present in the memo, attached to group 8, but that group now has a PhyOp_NOP implementation. Skipping over the rest of cost-based optimization (in a belated attempt at brevity) we can see the optimizer’s final output using trace flag 8607: This output shows the (incorrect, but understandable) 365 row estimate for the index range operation, and the correct 104 estimate still attached to its PhyOp_NOP. This tree still has to go through a few post-optimizer rewrites and ‘copy out’ from the memo structure into a tree suitable for the execution engine. One step in this process removes PhyOp_NOP, discarding its 104-row cardinality estimate as it does so. To finish this section on a more positive note, consider what happens if we add an OVER clause to the query aggregate. This isn’t intended to be a ‘fix’ of any sort, I just want to show you that the 104 estimate can survive and be used if later cardinality estimation needs it: SELECT Days = COUNT_BIG(*) OVER () FROM dbo.Calendar AS C WHERE theYear = 2013 AND isWeekday = 0; The estimated execution plan is: Note the 365 estimate at the Index Seek, but the 104 lives again at the Segment! We can imagine the lost predicate ‘isWeekday = 0’ as sitting between the seek and the segment in an invisible Filter operator that drops the estimate from 365 to 104. Even though the NOP group is removed after optimization (so we don’t see it in the execution plan) bear in mind that all cost-based choices were made with the 104-row memo group present, so although things look a bit odd, it shouldn’t affect the optimizer’s plan selection. I should also mention that we can work around the estimation issue by including the index’s filtering columns in the index key: CREATE NONCLUSTERED INDEX Weekends ON dbo.Calendar(theYear, isWeekday) WHERE isWeekday = 0 WITH (DROP_EXISTING = ON); There are some downsides to doing this, including that changes to the isWeekday column may now require Halloween Protection, but that is unlikely to be a big problem for a static calendar table ;)  With the updated index in place, the original query produces an execution plan with the correct cardinality estimation showing at the Index Seek: That’s all for today, remember to let me know about any Switch plans you come across on a modern instance of SQL Server! Finally, here are some other posts of mine that cover other plan operators: Segment and Sequence Project Common Subexpression Spools Why Plan Operators Run Backwards Row Goals and the Top Operator Hash Match Flow Distinct Top N Sort Index Spools and Page Splits Singleton and Range Seeks Bitmaps Hash Join Performance Compute Scalar © 2013 Paul White – All Rights Reserved Twitter: @SQL_Kiwi

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  • The UIManager Pattern

    - by Duncan Mills
    One of the most common mistakes that I see when reviewing ADF application code, is the sin of storing UI component references, most commonly things like table or tree components in Session or PageFlow scope. The reasons why this is bad are simple; firstly, these UI object references are not serializable so would not survive a session migration between servers and secondly there is no guarantee that the framework will re-use the same component tree from request to request, although in practice it generally does do so. So there danger here is, that at best you end up with an NPE after you session has migrated, and at worse, you end up pinning old generations of the component tree happily eating up your precious memory. So that's clear, we should never. ever, be storing references to components anywhere other than request scope (or maybe backing bean scope). So double check the scope of those binding attributes that map component references into a managed bean in your applications.  Why is it Such a Common Mistake?  At this point I want to examine why there is this urge to hold onto these references anyway? After all, JSF will obligingly populate your backing beans with the fresh and correct reference when needed.   In most cases, it seems that the rational is down to a lack of distinction within the application between what is data and what is presentation. I think perhaps, a cause of this is the logical separation between business data behind the ADF data binding (#{bindings}) façade and the UI components themselves. Developers tend to think, OK this is my data layer behind the bindings object and everything else is just UI.  Of course that's not the case.  The UI layer itself will have state which is intrinsically linked to the UI presentation rather than the business model, but at the same time should not be tighly bound to a specific instance of any single UI component. So here's the problem.  I think developers try and use the UI components as state-holders for this kind of data, rather than using them to represent that state. An example of this might be something like the selection state of a tabset (panelTabbed), you might be interested in knowing what the currently disclosed tab is. The temptation that leads to the component reference sin is to go and ask the tabset what the selection is.  That of course is fine in context - e.g. a handler within the same request scoped bean that's got the binding to the tabset. However, it leads to problems when you subsequently want the same information outside of the immediate scope.  The simple solution seems to be to chuck that component reference into session scope and then you can simply re-check in the same way, leading of course to this mistake. Turn it on its Head  So the correct solution to this is to turn the problem on its head. If you are going to be interested in the value or state of some component outside of the immediate request context then it becomes persistent state (persistent in the sense that it extends beyond the lifespan of a single request). So you need to externalize that state outside of the component and have the component reference and manipulate that state as needed rather than owning it. This is what I call the UIManager pattern.  Defining the Pattern The  UIManager pattern really is very simple. The premise is that every application should define a session scoped managed bean, appropriately named UIManger, which is specifically responsible for holding this persistent UI component related state.  The actual makeup of the UIManger class varies depending on a needs of the application and the amount of state that needs to be stored. Generally I'll start off with a Map in which individual flags can be created as required, although you could opt for a more formal set of typed member variables with getters and setters, or indeed a mix. This UIManager class is defined as a session scoped managed bean (#{uiManager}) in the faces-config.xml.  The pattern is to then inject this instance of the class into any other managed bean (usually request scope) that needs it using a managed property.  So typically you'll have something like this:   <managed-bean>     <managed-bean-name>uiManager</managed-bean-name>     <managed-bean-class>oracle.demo.view.state.UIManager</managed-bean-class>     <managed-bean-scope>session</managed-bean-scope>   </managed-bean>  When is then injected into any backing bean that needs it:    <managed-bean>     <managed-bean-name>mainPageBB</managed-bean-name>     <managed-bean-class>oracle.demo.view.MainBacking</managed-bean-class>     <managed-bean-scope>request</managed-bean-scope>     <managed-property>       <property-name>uiManager</property-name>       <property-class>oracle.demo.view.state.UIManager</property-class>       <value>#{uiManager}</value>     </managed-property>   </managed-bean> In this case the backing bean in question needs a member variable to hold and reference the UIManager: private UIManager _uiManager;  Which should be exposed via a getter and setter pair with names that match the managed property name (e.g. setUiManager(UIManager _uiManager), getUiManager()).  This will then give your code within the backing bean full access to the UI state. UI components in the page can, of course, directly reference the uiManager bean in their properties, for example, going back to the tab-set example you might have something like this: <af:paneltabbed>   <af:showDetailItem text="First"                disclosed="#{uiManager.settings['MAIN_TABSET_STATE'].['FIRST']}"> ...   </af:showDetailItem>   <af:showDetailItem text="Second"                      disclosed="#{uiManager.settings['MAIN_TABSET_STATE'].['SECOND']}">     ...   </af:showDetailItem>   ... </af:panelTabbed> Where in this case the settings member within the UI Manger is a Map which contains a Map of Booleans for each tab under the MAIN_TABSET_STATE key. (Just an example you could choose to store just an identifier for the selected tab or whatever, how you choose to store the state within UI Manger is up to you.) Get into the Habit So we can see that the UIManager pattern is not great strain to implement for an application and can even be retrofitted to an existing application with ease. The point is, however, that you should always take this approach rather than committing the sin of persistent component references which will bite you in the future or shotgun scattered UI flags on the session which are hard to maintain.  If you take the approach of always accessing all UI state via the uiManager, or perhaps a pageScope focused variant of it, you'll find your applications much easier to understand and maintain. Do it today!

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  • April 30th Links: ASP.NET, ASP.NET MVC, Visual Studio 2010

    - by ScottGu
    Here is the latest in my link-listing series. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] ASP.NET Data Web Control Enhancements in ASP.NET 4.0: Scott Mitchell has a good article that summarizes some of the nice improvements coming to the ASP.NET 4 data controls. Refreshing an ASP.NET AJAX UpdatePanel with JavaScript: Scott Mitchell has another nice article in his series on using ASP.NET AJAX that demonstrates how to programmatically trigger an UpdatePanel refresh using JavaScript on the client. ASP.NET MVC ASP.NET MVC 2: Basics and Introduction: Scott Hanselman delivers an awesome introductory talk on ASP.NET MVC.  Great for people looking to understand and learn ASP.NET MVC. ASP.NET MVC 2: Ninja Black Belt Tips: Another great talk by Scott Hanselman about how to make the most of several features of ASP.NET MVC 2. ASP.NET MVC 2 Html.Editor/Display Templates: A great blog post detailing the new Html.EditorFor() and Html.DisplayFor() helpers within ASP.NET MVC 2. MVCContrib Grid: Jeremy Skinner’s video presentation about the new Html.Grid() helper component within the (most awesome) MvcContrib project for ASP.NET MVC. Code Snippets for ASP.NET MVC 2 in VS 2010: Raj Kaimal documents some of the new code snippets for ASP.NET MVC 2 that are now built-into Visual Studio 2010.  Read this article to learn how to do common scenarios with fewer keystrokes. Turn on Compile-time View Checking for ASP.NET MVC Projects in TFS 2010 Build: Jim Lamb has a nice post that describes how to enable compile-time view checking as part of automated builds done with a TFS Build Server.  This will ensure any errors in your view templates raise build-errors (allowing you to catch them at build-time instead of runtime). Visual Studio 2010 VS 2010 Keyboard Shortcut Posters for VB, C#, F# and C++: Keyboard shortcut posters that you can download and then printout. Ideal to provide a quick reference on your desk for common keystroke actions inside VS 2010. My Favorite New Features in VS 2010: Scott Mitchell has a nice article that summarizes some of his favorite new features in VS 2010.  Check out my VS 2010 and .NET 4 blog series for more details on some of them. 6 Cool VS 2010 Quick Tips and Features: Anoop has a nice blog post describing 6 cool features of VS 2010 that you can take advantage of. SharePoint Development with VS 2010: Beth Massi links to a bunch of nice “How do I?” videos that that demonstrate how to use the SharePoint development support built-into VS 2010. How to Pin a Project to the Recent Projects List in VS 2010: A useful tip/trick that demonstrates how to “pin” a project to always show up on the “Recent Projects” list within Visual Studio 2010. Using the WPF Tree Visualizer in VS 2010: Zain blogs about the new WPF Tree Visualizer supported by the VS 2010 debugger.  This makes it easier to visualize WPF control hierarchies within the debugger. TFS 2010 Power Tools Released: Brian Harry blogs about the cool new TFS 2010 extensions released with this week’s TFS 2010 Power Tools release. What is New with T4 in VS 2010: T4 is the name of Visual Studio’s template-based code generation technology.  Lots of scenarios within VS 2010 now use T4 for code generation customization. Two examples are ASP.NET MVC Views and EF4 Model Generation.  This post describes some of the many T4 infrastructure improvements in VS 2010. Hope this helps, Scott P.S. If you haven’t already, check out this month’s "Find a Hoster” page on the www.asp.net website to learn about great (and very inexpensive) ASP.NET hosting offers.

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  • Can't install git on Ubuntu 12.10

    - by Lucas Windir
    I'm following these instructions to install git on my laptop: http://git-scm.com/download/linux When I do: $ sudo apt-get install git-core This is what my terinal shows: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libasprintf0c2:i386 libcroco3:i386 libgettextpo0:i386 libgomp1:i386 libunistring0:i386 Use 'apt-get autoremove' to remove them. The following extra packages will be installed: git git-man liberror-perl Suggested packages: git-daemon-run git-daemon-sysvinit git-doc git-el git-arch git-cvs git-svn git-email git-gui gitk gitweb The following NEW packages will be installed: git git-core git-man liberror-perl 0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded. Need to get 6,825 kB of archives. After this operation, 15.3 MB of additional disk space will be used. Do you want to continue [Y/n]? y WARNING: The following packages cannot be authenticated! liberror-perl git-man git git-core Install these packages without verification [y/N]? E: Some packages could not be authenticated lucas@lucas-Inspiron-N5050:~$ sudo apt-get install git-core Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libasprintf0c2:i386 libcroco3:i386 libgettextpo0:i386 libgomp1:i386 libunistring0:i386 Use 'apt-get autoremove' to remove them. The following extra packages will be installed: git git-man liberror-perl Suggested packages: git-daemon-run git-daemon-sysvinit git-doc git-el git-arch git-cvs git-svn git-email git-gui gitk gitweb The following NEW packages will be installed: git git-core git-man liberror-perl 0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded. Need to get 6,825 kB of archives. After this operation, 15.3 MB of additional disk space will be used. Do you want to continue [Y/n]? y WARNING: The following packages cannot be authenticated! liberror-perl git-man git git-core Install these packages without verification [y/N]? y Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main liberror-perl all 0.17-1 Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git-man all 1:1.7.10.4-1ubuntu1 Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git amd64 1:1.7.10.4-1ubuntu1 Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git-core all 1:1.7.10.4-1ubuntu1 Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/libe/liberror-perl/liberrorperl_0.17-1_all.deb Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/g/git/git-man_1.7.10.4-1ubuntu1_all.deb Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/g/git/git_1.7.10.4-1ubuntu1_amd64.deb Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) Failed to fetch http://py.archive.ubuntu.com/ubuntu/pool/main/g/git/git-core_1.7.10.4-1ubuntu1_all.deb Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname) E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing? How could I install git on Ubuntu 12.10? I can't even do it from the Ubuntu Software Center. Thanks in advance!

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