WebResource.axd gives 404

My colleague, Michael Knudsen, has been struggling with a customer & partner for several hours now with an annoying problem on an EPiServer 4.62 site just moved to a production server. Finally, after browsing through half the web and getting valuable feedback from most supporters / developers known to man, a simple solution was discovered.

To save other people the agony he's gone through he persuaded me to post the solution here...

 

Problem symptoms:

When clicking on a button in a webform the following javascript error occurs: Webform_Postbackoptions is undefined. A little simple debugging later it turns out that the page in fact did get a 404 when requesting a web resource (javascript) from the server - which is where the method is defined.

<script src="/WebResource.axd?d=14ZW9Y1So0D_eFk6_pguuw2&amp;t=633359999849186250" type="text/javascript"></script>

If you don't know what webresources does there's a good intro here. This problem had us all stunned for a while - lots of theories going through our heads...."It must be a web.config problem - some handlers are interfering with each others", "Perhaps asp.net isn't properly installed on the server", "But it's working on my machine", "Is this using AJAX?", "Can't we just put the dev. server where it works into production", etc. were some of the thoughts going through our heads as the problem took over our common sense.

 

Solution:

Uncheck this checkbox in IIS:

 

 

Skype and Port 80

This is probably old news to a lot of people, but I just ran into an error message in IIS7 on my Vista saying that "The process cannot access the file because it is being used by another process" whenever I tried to start my default website.
Ah well, I thought...Better shut down various other applications although I was wondering what file it could possibly be that there was a sharing conflict on. So, all other app's seemingly shut down, but I still couldn't start my website.
Before I got the error I had been spending numerous hours getting more and more annoyed at IIS7 so I concluded that this was probably something caused by yet another pseudo-paranoid default security setting somewhere - and I guessed that the error was probably misleading and in fact not related to files at all.
Luckily at this point Ruwen came to my rescue and pointed out the obvious that I somehow had missed:
Ruwen: "it could be skype blocking the port 80"

And it turned out that he was (as always) right. Skype listens by default on port 80 and thereby blocks the device (LISTEN on 80) that IIS is using when starting a site.
After visiting Skype's advanced settings and turning off that obscene feature saved my day.

XSLT in EPiServer CMS 5

Personally I'm not a big fan of neither XSLT nor XML. In fact, my feelings around XML is expressed in this quote I heard recently: "XML is like children. They start out cute and small, then they grow..." (I don't remember who said it - if it was YOU, mail me and tell me to credit you for those words of wisdom). In my opinion XSLT's are mainly just good for job-security for XSLT developers - they are about as friendly to read as regular expressions - and terrible to maintain. Nevertheless a lot of people like them due to the way they help separate design from data - and I've already been asked the question "how can I work with XSLT in EPiServer" many times. So, now I thought I better do something about it, so one dark and cold evening I made a web control that hopefully will satisfy all the XSLT magicians out there!

The control will create a XML document representing the current page that has this structure:
    <page>
        <properties>
            <property name="PageLink" type="PageReference" isdynamic="False" isnull="False">3</property>
            ...
        </properties>
        <children>
            <page>
                ...
            </page>
        </children>
    </page>
and then transform that XML using the XSLT you provide.

In order to use the control, you'll need to place the dll in the "bin" folder, and register it on the page you wish to use it on. Then you can put it on the page like this:

<research:XSLT runat="server" id="xslt2" MaxChildDepth=1 IncludeDynamic="true"> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" xmlns="http://www.w3.org/1999/xhtml"> <xsl:output method="html"/> <xsl:template match="page"> <h1><xsl:value-of select="properties/property[@name='PageName']"/></h1> <ul> <xsl:for-each select="properties/property"> <li><xsl:value-of select="@name"/>: <xsl:value-of select="."/></li> </xsl:for-each> <li> Children: <xsl:apply-templates select="children/page"/> </li> </ul> <br /> </xsl:template> </xsl:stylesheet></research:xslt>

In the above case the XSLT is specified within the controls tag, but you can also reference an external xslt file, by setting the property "TransformationFile" to the url of the XSLT file. Or - if you're feeling mean - you can bind the XSLT contents to a LongString property in EPiServer and let the editors figure out the extended stylesheets - that'll freak them out for sure :-)

By default the control will begin with rendering the XSLT on the current page data - if you want to base it on another page, it can be set up in well-known "PageLink" and "PageLinkProperty" properties.  The "IncludeDynamic" property specifies whether to include dynamic properties or not, and the "AutoHtmlDecode" property specifies if html-tags within properties should be rendered as HTML tags or as text on the page.

Find the control on labs.episerver.com

P.S. If you insist on playing around with XSLT and use this control, I wrote a XPathChecker some time ago that might come in handy.

Parallel Computing Made Easy

At the Developer Conference, Øredev, earlier this week I had a chance to see a session about Microsoft's upcoming ParallelFX - the .NET toolkit for working utilizing multiprocessor machines - and it really looks promising!

The basic idea is that it should be a lot easier to utilize multi-processors from code than it is today. Sure, we have System.Threading and it's QueueUserWorkItem, Threads and some Async execution - but they are difficult to use in the most efficient manner. It's not easy to distribute a series of parallel tasks to threads in the way so that they will be distributed among the processors in the most sensible way!

This is where ParallelFX comes in. A part of it are some simple classes - both for Data Distribution (when you distribute the data you need processed so it's processed in parallel) and also to some degree Task Distribution - where you split up your tasks to run parallel wherever it makes sense.  The methods that make it all possible are for example the Parallel.For( ... ), Parallel.ForEach(...) and Parallel.Do(...) that all take delegates - or Lambda expressions (essentially the same). By introducing these methods it'll now be a lot easier to take typical tasks like For loops and speed them up a lot!

I can imagine a lot of For loops out there that perform non-interrelated operations (e.g. they are not dependent on each others execution) that will benefit with a small ParallelFX performance refactoring.