Archive for January, 2007

When working with a complex environment such as the ones being created by most (if not all) AJAX applications nowadays, one needs a set of tools in his/her arsenal to overcome any obstacle.

FireBug, a web development and debugging extension for Firefox is one such tool that you must keep close.

As it site says:

Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

If you are not already using it go quickly, download and start working with it.

There are two major benefits of using FireBug when developing ASP.NET and AJAX.NET application:

  1. HTML Inspection – FireBug allows you during runtime and on any site, to inspect how the HTML looks. This includes direct references to the various stylesheets being used an element (including the casecading parts and from which .css file they came from). It also includes the ability to visualize the unvisible styling elements of padding and visualize so that you’ll visually see where the styling problem is as well as change the various style settings on the fly and immediately see the results.
  2. JavaScript Debugger – The JavaScript debugger and expression evaluator in FireBug are a lot easier to use and are a lot more powerful than the ones supplied by Internet Explorer combined with Visual Studio (or what is actually Active Scripting Debugging from the happy old COM days 🙂 ). Visual Studio is a very heavy debugger and sometimes lacks the ability to debug even sites and JavaScript that you just want to know how they work, without having the actual code of the site.

In the early days of AJAX.NET (or should I say in the “Atlas” days), FireBug was my main weapon of understanding the AJAX.NET framework and stepping line by line to understand how to use and work with AJAX.NET.

It’s an invaluable tool in your arsenal and with the usage of AJAX.NET increasing on a daily basis you just have to have it.

At my day job, we started getting a strange compilation error when accessing one of the pages (the ASPX file).

Upon first access to an ASPX file, ASP.NET parses the ASPX file and combines it with the ASPX.cs/ASPX.vb (code behind) to create one single .cs/.vb file, compile it and loads it into the memroy.

The error was quite strange:

The type or namespace name ‘Compatibility’ does not exists in the namespace ‘System.Web.UI’ (are you missing an assembly reference?)

This was just a simple page. Not fancy AJAX code. You can see how it looked when I set customErrors=”true” in the web.config here.

After digging a bit more, I’ve turned on the debug=”true” in the <compilation> tag in the web.config file and got a more details error (look at the screenshot here).

I was not familiar with any System.Web.UI.Compatibility namespace in ASP.NET so I searched throughout the project. I came across this namespace in the web.config file itself in the <system.web> \ <pages> \ <tagMapping>.

This set of configuration tags is added for use with AJAX.NET and it simply says that if you see System.Web.UI.WebControls.CompareValidator replace it with System.Web.UI.Compatibility.CompareValidator that is found at System.Web.Extensions – System.Web.Extensions is one of the AJAX.NET assemblies.

A light bulb flickered above my head and I figured that the problem was in the ASPX compilation.

When you set debug=true in the <compilation> tag in the web.config, the path at the bottom of the error page will actually include the temp .cs/.vb file ASP.NET has created as well as a few .cmd file which are in fact the command line passed to the C#/VB.NET compiler to compile the code.

I checked it out and it seems System.Web.Extensions was missing from the command line.

I’ve added it to the <compilation> \ <assemblies> and it worked.

I still don’t know what is the exact cause of this problem, but I figured having an extra reference in the compilation shouldn’t cause any harm. At least for now.

I had a couple of problems in the transfer with the feed of the new blog (

It is redirected to the Feed Burner feed and should be working OK now. The auto discovery of the feed should also work (I hope).

Please let me know if there are still problem with it.

Hey all,

Let me welcome you to the new home of Advanced .NET Debugging.

Having a new home and a new address will let me experiment a little bit more with this blog.

If you don’t already know, I have a personal blog, in which I talk about other things not related to .NET debugging (though sometimes it is related to programming and development in general).

I recently got a little bit more involved in identity online. That’s why this blog also has my MicroID WordPress plugin as well as my OpenID Delegation WordPress plugin and will allow you to authenticate yourselves with OpenID to add your comments.

These little things are important to me, being the geek that I am and I hope it will help you, me and the rest of the Internet community.

Anyhow, enjoy and don’t forget to tell your friends 😉

You know I don’t like to be an echo blog, but I couldn’t give up on such a fine piece of code.
This is really one of the things I said to myself “How didn’t I think of that before?” 🙂

Mike Stall has a great post and a piece of code that he wrote about using P/Invoke to access unmanaged Windows API code.

He has written a rather generic wrapper that does all the dirty LoadLibrary, GetProcAddress code and you can generically get a function and execute it without thinking twice.
It uses SafeHandles and make all the necessary releases (if you use it correctly) without you having to worry about it.

Check it out (don’t forget to read the disclaimer he wrote there) and have lots of P/Invoke fun.

I bet one of you (or maybe even me if I’ll find some time) can write a code generation utility that will use this code to create a wrapper for most of the unmanaged Windows API code that goes around making it even more type-safe in the sense if not having to pass around strings to get function names and having to deal with a generics deceleration of the function you are using.

Forgive me for a non technical post but apparently I’ve been tagged by Tess which means I probably need to say 5 things about myself. Hmpf…

Oh well, here it goes:

  1. I can’t eat tomatoes. I can eat them in the form of ketchup and in the form of a sauce (on Italian food, for example), but I simply can’t bare the thought (or taste) of having a raw live tomato in my mouth (yuck!)
  2. I have yet to complete any formal degree from a formal institution what so ever. I’ve finished about 1/3 of a Computer Science degree in the Open University in Israel. I simply figured since I’m already rather proficient in CS I would be better off actually studying something else. I’m still considering Philosophy but haven’t had the time to make it so, mainly because I work full time and the Open University doesn’t have a Philosophy degree (perhaps its time for University 2.0, something that will actually fit people like me 🙂 ).
  3. I learned and/or playing the following musical instruments: Flute, Saxophone (soprano, alto, tenor and Baritone), Guitar (electric, classical, acoustic and bass), Piano (not enough to play Rachmaninoff, but enough to understand the basics and compose music on it), Drums (not too well, but enough to keep a steady beat)
  4. I own a Sea Kayak (an Ocean Kayak Scupper Pro) which I’ve been taking off to sea in the summer (I still haven’t gotten a dry swim suite like the divers have to actually kayak in the winter). It looks rather funny on my car’s roof (a Peugeot 206) since the car is 3.8 meters long and the Kayak is 4.5 meters. I’m starting small. My first goal is that in the Summer of 2007 I’ll Kayak from Hertzliya to Tel Aviv and back (around 30km).
  5. I’m going to be 26 in 17 days (21st of January) but I’m still being referred to as the Kid (or sometimes Wiz Kid) by my co-workers, mainly because I formally started to work in the industry at the age of 16 and I’m still the youngest person at work.

OK, now I need to find 5 other people I wish to tag. I feel kind of sleazy continuing this blogosphere chain letter like effect, but what the heck. Let’s go with the flow.

I’m hereby tag Alex, Shay, Liron, Eran (not me) and Yossi.

In my previous post about problems with wrongful escaping of the query part in the uri in Request.QueryString, I’ve received a comment from a reader named DuncanS saying that he encountered a similar behavior with the Uri class.

It seems Uri.ToString() function will perform unnecessary unescaping of the different parts of the Url that were escaped (like the query part) to be unescaped.

His solution to the problem is to use Uri.AbosluteUri instead which does not exhibit this behavior.

Thanks for the tip Duncan!