RegexConverter on Github!

Update: two more days of work and a huge text file of regular expressions and I know a lot more about the syntax of .Net Regex than even MSDN :)
The third (Apr11) release of the library has a huge load of bug fixes and new features and it is now... [Tadaaaaa]... a stable version. At least I think of it that way :) Go download it.!

I've been working for two days on an idea. What can I do to make those long regular expressions that I always leave in my code more readable and easy to understand without having to compile automatons in your head?

I have first researched on Google regular expression converters. Nothing was even close to what I wanted. Also, on the more scientific side, people were talking a lot about BNFs, as a superset of regular expression syntax. I looked at BNF. Yes, it describes anything in a human readable form, it is used in RFCs but I hate it even more than XML! So XML it is. Most of the inspiration for the code came from this link: Regular expressions and regular grammars

I give you, RegexConverter. It is a library+demo that transforms a Regex into an XML and then back again. The demo application demonstrates (duh!) this by having two panes, one in which to write regex and the other in which to write XML. Changing one, also changes the other. It warns you of errors in both Regex, RegexConverter and then checks if what it got can be safely converted into your changed string!

Please tell me what you think. I believe it can be a real help in understanding regular expressions, some specific ones or regular expression syntax in general, whether one is a pro or a complete noob.

I've worked hard to design the library source in a way that is understandable, I also added comments everywhere. I tried to implement all the specifications of .NET regular expressions from the MSDN site so if you have a regex that is valid but can't be turned into XML or the conversion is not perfect, let me know.

The link is: RegexConverter on Github.

I will update this post with more science and links to my places of inspiration for this, so stay tuned.

Update: Ok, so I haven't updated this post much. Shame on me. I was reminded of this project when I got an email from the FamousWhy site which said RegexConverter "has been granted the Famous Software Award". I know it's probably an automatically generated message and went to many or all of the Codeplex people, but still: automated attention is still attention :)

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Type names for nested classes

Just a small mention of a thing I've learned today: what is the FullName of a Type of a class that is nested into another?

Usually, you would use it inside Visual Studio as ParentClass.ChildClass, but if you ever want to use the full name of the ChildClass Type (as when declaring it in web.config) you have to separate them with the + (plus) sign.

So let's assume you have this MyHandler class in the MyNamespace namespace which has a nested class Configuration in it. In the code you do a

var conf = new MyNamespace.MyHandler.Configuration();

while when using the handler type name to declare it in web.config you do it like this:

type="MyNamespace.MyHandler+Configuration"

.

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customErrors=Off not working!

First off, I have to say something about forums: stop copying content from one another, jerks!. I have been trying to find a solution for this problem and I found a zillion forum pages with the same "problems" and the same "solutions" again and again and again!

Much better! Now, I have been trying for an hour to understand why setting customErrors="Off" in the web.config of my ASP.Net application would not work. I tried just about anything, including the bloody forums. customErrors Off did not work!.

In the end I found one little comment for a StackOverflow question: set the retail setting in the machine.config file to "false"!! So, go to %WINDOWS%\Microsoft.NET\Framework\v2.0.50727\CONFIG\machine.config and set retail to false!. Setting it to true means it will NEVER show you any useful debugging message.

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FastListAdapter on Github

A while ago I wrote a post detailing a fix for Very slow UpdatePanel refresh when containing big ListBoxes of DropDownLists. I have restructured the fix into a ControlAdapter and placed it on Github.

Enjoy!

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Internet Explorer 8 installation fails and then browser crashes. Solved by updating Sun's Java?!

Today Internet Explorer 8 appeared to me in the Automatic Updates list. I have been using IE8 for months now and so I was glad that the official release finally came out. So I downloaded and installed IE8.

The installation process has several steps. First is the removal of any previous version of IE, then a reboot, then several small steps of the setup program: Downloading IE8, Downloading IE8 updates, Installing IE8, Installing updates, Finishing installation. Well, for me, at the Installing updates step it threw an error that said the installation cannot complete because the station is shutting down, then my computer restarted.

I did have Internet Explorer available, though, so I tried a few pages. After the pages loaded, I was invariably getting an error and IE closed. "Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience.". Well, so was I!

I was trying the installation of IE the third time now and suddenly a Java update traybar icon appeared. I updated Java, then I was amazed to see that IE was no longer crashing! So, my solution for Microsoft IE errors: update Sun Java! :)

Well, the Java update probably completed some steps that the installer failed to. But still :)

And interesting link I found regarding any IE error that causes the browser to excuse itself and leave is on Sandi's Site

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The Sift string distance algorithm is now on Github

I've gathered the strength to defeat my laziness and put another of my projects on Github. I am talking about the Sift3 algorithm, described here.

The URL for the project is https://github.com/Siderite/Sift3/ where you can download the library and sources in .Net 3.5 C#. A class that also implements Levenstein and Length string distance algorithms is provided.

Please let me know if you are interested in the project, have any suggestions or are even using the algorithm in your projects.

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Http error 405: The HTTP verb POST used to access path 'something' is not allowed for IIS5 in Windows XP

This error can happen in several situations. One of them is when you are trying to access a web service, another is when trying to call a classic asp page. Most of the time, this happens in situations related to URL rewriting. It may happen in Windows XP or Windows 2000, on IIS 5.0 or IIS 5.1.

Well, first of all, in order to do URL rewriting you need to make ASP.Net process ALL URLs, not only .aspx pages. To do that in IIS5, you need to go to the ISAPI extensions and add a new one for '*' that maps to the ASP.Net dll (aspnet_isapi.dll). This process is detailed in this Microsoft page: HOW TO: Use ASP.NET to Protect File Types. What that means is that when you see a GIF image, it will pass through the ASP.Net engine, firing all the usual events.

However, after you do that, you see that web services start behaving strangely. Why is that? One explanation says that "405 mostly comes about when you try to POST against a URL that is not considered dynamic by IIS". It doesn't much makes sense to me.

I have searched a lot for an elegant solution. The only one that actually applied was using a piece of code in the BeginRequest event in Global.asax (or maybe in a HttpModule that one has to register in web.config). It came from this forum: HTTP verb POST not allowed. Here is the code:

//The BeginRequest event is fired for every hit to every page in the site
    void Application_BeginRequest(Object Sender, EventArgs e)
    {
        var extensions = new[] {".asmx", ".svc"};
        foreach (var ext in extensions)
        {
            var index = Context.Request.Path.IndexOf(ext, StringComparison.CurrentCultureIgnoreCase);
            if (index <0) continue;
            
            var path = Context.Request.Path.Substring(0, index + ext.Length);
            var pathInfo = Context.Request.Path.Substring(index + ext.Length);
            var query = Context.Request.Url.Query ?? "";
            if (query.StartsWith("?")) query = query.Substring(1);
            Context.RewritePath(path, pathInfo, query);
            break;
        }
    }

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