The case of global.asax not being executed in IIS7

Global.asax is used in both asp.net MVC and OpenRasta for implementing your configuration. In Rasta 1.x, the handling of request was done through a catchall http handler. This has a couple of adverse effects for the application: all requests went through rasta first, and got delegated to IIS when there was no match. This can cause a range of performance issues, from lack of caching to constant file access when the delegation ends up using DefaultHandler rather than StaticHandler, as in those instances the files will systematically be streamed from the disk.

Another struggle I had with this system was the various issues encountered when trying to host the system on IIS7, something I started doing a while ago. I remembered reading from a blog that asp.net MVC was using both a handler and an http module, and investigated using a similar configuration for OpenRasta. As I do not want to be influenced by other people’s coding abilities, I have stayed away from reading the asp.net MVC source-code and tried to come up with my own scheme.

One particular issue comes from the different framework versions supported by OpenRasta: I run on plain old asp.net 2, and this means that all the new APIs that let you change a handler on the fly during a request will not work, as they are added by .net 3.5 sp1. Instead I came up with a clever trick: Just before the handler is resolved, I rewrite the url to a fake url, properly called ignoreme.rastahook. The extension rastahook is always associated with a compatibility handler that then gets called by the asp.net infrastructure, at which point I rewrite the url to what it was before the change, and execute my own http handler from there. The solution is not entirely perfect yet, as there is no support for asynchronous handlers, but as with every other part of OpenRasta I’ll be able to change that without impacting any handler already in existence.

As soon as I implemented those changes, everything went much more smoothly on IIS6 and cassini (the visual studio web server), but broke completely on IIS7 integrated mode on my local box. After much debugging, I realized that my global.asax wasn’t being called. When I added back an http handler to my web.config, the global.asax code was called again.

The reason is a bit confusing to understand at first. In IIS7 integrated mode, http modules are treated as being part of IIS, be it that they are managed or not. This means that a module may or may not rely on asp.net. Your module will be executed but your web app won’t necessarily have been compiled. Handlers on the other hand, when they are managed, trigger the asp.net application, and your code will get executed.

So to conclude this issue that i’ve been chasing for two months now: if you don’t have a managed http handler for your request, your http module will be called but the asp.net part of your site will not have been compiled and / or won’t be called, including global.asax. The solution is to ensure you have a managed handler in place, or force a compilation of the root site using BuildManager.GetReferencedAssemblies.

P.S.: this is all based on empirical evidence, so I may be absolutely wrong, and would be glad for anyone to come up with an alternative explanation.

Microsoft, for Christmas I’d like…

• A Visual Studio SP1 ++ that fixes all the bugs you’ve recently introduced
• A web designer that passes the ACID2 test
• A browser that implements the *freakin DOM*

I promise I won’t be a good boy, but then again, when I have to work with some of the tools you sell, I know who is to blame.

/me goes back to his office and wreck a few toys

The rubber duck in agile teams

Saw this from twitter and it made me smile: http://www.ademiller.com/blogs/tech/2008/08/scrum-bestiary-the-rubber-duck/

Have you had a rubber duck to deal with?

Proposing a syntax to attach behaviors to html elements

ScriptSharp, like asp.net AJAX, has the notion of behaviors, javascript code that can attach itself to DOM elements and change their, well, behavior.

As part of my spike on ScriptSharp (and I’ll have to admit having spent way too much time on it to still be called a spike), I’ve built a simple container that automatically resolves and binds behaviors to DOM elements, to reduce to a maximum the amount of inline code required within my generated pages.

The one thing I went round and round about was how to declare in markup that binding. Here’s a few solutions I tried or seen proposed through various tools.

<div style="behavior: url('myBehavior.htc')" />

This is something introduced in ie4, but it breaks the CSS standard *and* htc are only recognized by Internet Explorer. No good to me.

The next contender is…

<input type="text" id="searchText" /> <input type="button" id="searchButton" /> <script type="text/xml-script"> <page xmlns="http://schemas.microsoft.com/xml-script/2005"> <references> <add src="ScriptLibrary/Atlas/AtlasUI.js" /> <add src="ScriptLibrary/Atlas/AtlasControls.js" /> </references> <components> <textbox id="searchText" /> […]

…xml-script, and was originally presented early in the life of asp.net AJAX (back when it was called ATLAS). This is awfully verbose, and worse than that it won’t ever validate in non-xml languages (aha HTML 4.01 or XHTML5). The same is true of the proposed changes in asp.net AJAX Futures, which uses namespaces everywhere even though they’re not allowed in non xml renderings.

[Update: As Simon Pieters correctly points out in the comments, this syntax would indeed be compatible with HTML5 (the non-xml serialization one), because the definition of CDATA sections has been modified to include anything not including the closing tag. Hence what is after <script> can be anything that is not </script>. This redefined definition of a CDATA element is not something the XML specification agrees with however, which means that in all languages, aka XHTML 5.0, XHTML 1.1, XHTML 1.0 and HTML 4.01, you need to enclose the content of the script tag in a CDATA section, aka <![CDATA[ … ]]>. This makes HTML5 the only rendering with which xml-script would work. I may have misread some of those specs however, so if I have please comment and I’ll update and buy you a beer.]

In choosing how to map behaviors, I had several goals:

• declare the behaviors contextually within an element,
• being able to use the exact same notation for both HTML 4.01 (the SGML language), XHtml 1.0 and 1.1 (the XML language) and Html 5 (both the whatever it is format that is not sgml anymore *and* the xml language, as both exist)
• being able to pass additional customizations and parameters specific to an instance
• Not look too out of place.

I initially settled on an extension to the way content type definitions are expressed:

<div class="behavior/graphicscroll;horizontal=true;vertical=true;">test</div>

This says, ask the behavior family to add a graphicscroll behavior and pass it values for horizontal and vertical. All was good and I was happy with myself. For a whole five minutes.

Then you realize that while that syntax works like a charm, it is invalid in Xhtml 1.1, because the class attribute was redefined to be of type NMTOKENS, where the previous version had a type of CDATA. This is a serious breakage for content out there, and I wonder what the reason for this is.

The other issue I had with this is the need to declare the full syntax for each element I wanted to use, and I really wanted to leverage CSS selectors. One solution I would have wanted to use was to simply extend the CSS stylesheets with custom css attributes. This would have then looked like the following.

    <style type="text/css">

        div {

          -rasta: "behavior/graphicscroll;horizontal=true;vertical=true";

        }

    </style>

The syntax just felt very unnatural. And worse than that, the CSS validator doesn’t validate CSS with vendor expansions, even though they are defined as such in the specification.

After twiddling around endlessly, I’ve settled on defining a css-like language, behavior stylesheets, without some of the restrictions of the existing CSS. I now have this code:

    <style type="text/vnd.rasta.bss">

        div

        {

          behavior: graphicscroll {

              horizontal: true;

              vertical: true;

            }

        }

    </style>

The  selector syntax is simply the CSS one, which means you can combine and match them in the same way you would define your stylesheets. The properties however are dynamic, with the first level name always matching a family of components (implemented as a loader) with a value matching the component, and a sub-group letting you define properties on that component.

You’ll notice I mentioned my first goal was for this to be contextual within the element. Because you’re still using selectors, nothing prevents you from declaring a value in your class attribute and do your selection on that. The same of course goes for ids.

Time will tell if this is as compatible with current UAs as it could be, and I have the feeling it will be ignored when necessary, but it’s extensible, simple enough, doesn’t require the script engine, leverages an existing html element and still passes in all versions of html that support the style element.

When a provider ditch its own product…

I’m currently researching Server 2008 VPS products available, and stumbled upon bytehouse’s offering:

Why use a Windows operating system?

Windows Hosting is only really needed if you require ASP (Active Server Pages), Access Databases or VBScript.

Why use a Linux operating system?

If you just need to host HTML (Hypertext Markup Language) or PHP Web Pages, then Linux Hosting would be the better and cheaper choice for you. Linux has a proven track record of performance, stability and security within the Web Hosting industry.

Oh, god, I have Linux envy now, thanks!

Come and listen (or talk) about asp.net MVC in Brighton!

VBug apparently didn’t learn their lessons from the last presentations and asked me to come back to deliver my Bingo asp.net MVC talk in Brighton, the day before ReMix! You can have a look at the event, and frighteningly it is already fully booked!

You can expect a run-down of the MVC pattern, plenty of code (but less than last time), and of course Bingo.net in its third version. I may have some surprises in stock so be prepared for anything.

For anyone down in Brighton on that day, I’ll be staying there so expect a full attendance at the pub. The only true way to start any conference is with a hangover.

Using getElementsBySelector in ScriptSharp

I’m on my way to my second spike for one of my clients on playing with ScriptSharp to extend Rasta with Ajax functionality, and really wanted to be able to select elements as I would in CSS, using selectors (something I got quite used to with jQuery).

ScriptSharp comes with various assemblies you can link to. The one called sscorlib is a .net mapping over a javascript library that extends document to have a getElementsBySelector method. But for some reason, ScriptSharp doesn’t map that method.

So how do you call random code in ScriptSharp without resorting to evil eval code? You create a function of course! Here’s the snippet.

        public static DOMElement[] GetElementsBySelector(string selector, DOMElement root)

        {

            return new Function("return document.getElementsBySelector(selector, arg);", "selector", "arg")

                .Call(Document.DocumentElement, selector, root) as DOMElement[];

        }

We define a function that calls the correct javascript code, declare the argument names we will pass it, and finally call it by passing our selector and the root.

In one word, sweet.

Received this morning

Dear Sebastien

We are currently searching for a JOB TITLE to work in  CITY, COUNTRY  for DURATION plus extensions. This is a fantastic contract opportunity for a large multi-national client.

The ideal candidate must have the following skills: SHORT JOB DESCRIPTION.

A nice way to start the morning! Where do I sign?

“It doesn’t work”

Something seriously cracks me up. I hear day after day people telling me one technology or another, one tool or another, fails in matching their expectation, and explain the situation by it doesn’t work.

As soon as those words are muttered by someone in a team with low knowledge of the toolkit they are dealing with, you see developers running around to work around the symptom, replace the technology, or completely screw up an architecture or a design just to make it work.

Just the same, while TDD and fast feedback cycles have brought to the development community an antidote to the press F5, it works, I’m l33t, you still find a large number of rogue developers that still manage to write no test, go head down in development, produce unmaintainable code and still manage to lift it off because the UI is shiny and the managers don’t have a clue about the importance of quality and maintainability, as they don’t have the responsibility of their v2 budget.

Whenever faced with an intellectual challenge, you have two categories of people: those who step up, learn and understand a problem before finding a solution, and the it doesn’t work and Oh I press F5 I’m good! developers. My word of advice to the latter, if you are given guidance and mentoring and refuse to step up, you will eventually be out of work. Embrace change, challenge yourself and don’t discard mentoring when it’s given to you.

Updating Hyper-V to RTM

As is usually the case when you’re under pressure to push a new release of an app for a client, something goes horribly wrong.

What went wrong tonight is simple: my Server Core install was never updated to hyper-v RTM, but windows update did its job fine on one of the client VMs that also runs Server 2008. Suddenly, the whole server is down.

Second install on the core install and still failing. I wonder how I’m going to apologize profusely to my client tomorrow. Oh the joy.

[Update 03:22: License wasnt activated properly, trying yet another install…]

[Update 04:05: Need my bed. Trying an uninstall of the role, followed by an update with the .msu. If that works I’ll reinstall the Hyper-V role tomorrow]

[Update 04:13: Apparently uninstalling the role rebooted the machine which then updated itself on its won with the RTM version. Don’t know if I should cry or laugh. Reinstalling the role now (seeing as there’s one less boot as previously expected, I have a boot to spare)]

[Update 04:27: All back in order, machines are up. Lost 6 hours of my life, less than impressed.]