• Test Driven Development for Silverlight – Introduction
• Part 2 – covers a navigation application
• Part 3 – jumps into integration testing (more than just unit testing)

It’s great seeing the community getting involved in expanding knowledge and the references out there. Thanks Eric!

One of the most important messages that I had during the talk is the flexibility that the Microsoft Client Platform enables: you can be a Rich Internet App developer today, and build an enterprise Line of Business app tomorrow, since so many of the concepts, APIs, and ideas are shared between these frameworks.

Download session deck (4.7 MB PowerPoint 2007)
View the session on the VisitMix.com site: http://videos.visitmix.com/MIX09/T87F

Check out other awesome Silverlight, WPF, and Expression. Hope this helps. Let me know what you think.

I’ve compiled a quick screencast (6:07) that demonstrates preparing a directory to check in the proper SDK components, updating a C# project file, and then proving the result by uninstalling the Silverlight SDK.

Walkthrough video

6:07, 60MB, HD 720p (Download WMV)

Properties respected by the Silverlight MsBuild targets

The Silverlight build system respects these build properties that can override the standard SDK locations:

The runtime version is used when generating the application manifest and HTML test page.

Preparing your source enlistment

On the Toolkit, we have a directory of external tools and engineering resources. One of these contains the Silverlight SDK’s assemblies, libraries, and build scripts, as shown in the video.

• Create a directory to store the MsBuild assets for Silverlight, and copy in the files from %programfiles%MSBuild\Microsoft\Silverlight\v2.0.
• Copy the “Reference Assemblies” directory from %programfiles%\Microsoft SDKs\Silverlight\v2.0\ into the tools directory.
• Copy the “Libraries” directory from %programfiles%\Microsoft SDKs\Silverlight\v2.0\ into the directory.

You can then use relative paths in your projects or custom build targets to get things rolling.

Updating projects

Depending on your build system, you’ll want to update your custom targets or project files. In the video I’m simply modifying the .csproj file to add the necessary properties and modify the import statement.

Add properties

I’d scroll through the .csproj and insert the new properties right before the Import statement that pulls in the Silverlight build targets. Here are the properties defined; the SilverlightBuildResources property is my own made-up name that I’m using to store the relative path to the new building bits:

  <PropertyGroup>
    <SilverlightBuildResources>..\Build\</SilverlightBuildResources>
    <TargetFrameworkDirectory>$(SilverlightBuildResources)Reference Assemblies\</TargetFrameworkDirectory>
    <TargetFrameworkSDKDirectory>$(SilverlightBuildResources)Libraries\Client\</TargetFrameworkSDKDirectory>
    <SilverlightRuntimeVersion>2.0.31005.0</SilverlightRuntimeVersion>
  </PropertyGroup>

Import the new Silverlight build target

Silverlight projects import the Silverlight MsBuild targets from the central MsBuild extensions directory, so we just need to update the import to instead come from the source tree:

  <Import Project="$(SilverlightBuildResources)Microsoft.Silverlight.CSharp.targets" />
  <!--
	This is the default provided for new Silverlight projects:
  <Import Project="$(MSBuildExtensionsPath)\Microsoft\Silverlight\v2.0\Microsoft.Silverlight.CSharp.targets" />
  -->

Build

You’re all set! And, for future reference: you can use this to build applications targeting multiple versions of Silverlight from the same tree. But more on that later.

This really cuts down on the moving parts from the previous 1.0 templates that had dependencies on so many loose JavaScript files.

I wanted to blog about my experience in case others ran into this: if you have your Xap files on a domain different than your pages, you might find that the Silverlight plugin is blank and the media player never loads. This is a by-design feature per the Silverlight HTML DOM bridge security model – but you can actually do a few things to get this to work.

I host my Silverlight applications and media assets on a separate domain. This creates the situation where the bridge is disabled; if you would like to reference the .Xap files from different sites or enable others to embed your video player, it won’t work out of the box unless you modify the <object /> tag or modify and rebuild the managed media player to gracefully move on in this situation.

Here’s the breakdown that I have for my web pages vs. my Silverlight assets, including the apps:

The additional parameter within the object tag will be easiest for most folks, and is probably the way that the Expression team hopes that you’ll enable this scenario. I always forget things like modifying the object tags, since this isn’t in the default generated HTML file that Encoder outputs, so I’m going for a more involved solution.

Oh, and don’t get me wrong: SP1 rocks. I highly recommend that you install it; I’m getting so much more use out of Encoder 2 now. If you haven’t purchased Encoder… well, you really should try or buy it. With SP1 it not only adds the nice Silverlight 2 templates, but also H.264 mobile encoding. I was able encode my screencast in H.264, and it looks great on my iPhone!

The HTML DOM Bridge security model in Silverlight

Per the DOM bridge security model in Silverlight 2, the default behavior when the .Xap is hosted on a domain different than your web page, is that the HTML DOM bridge feature will be disabled for that Silverlight application in the .Xap. The DOM bridge is used by the managed media player to get the document URI property when trying to look up relative-path video assets.

This situation can also present itself on the same domain, when the web page author explicitly denies the HTML DOM bridge access to a plugin: if the <param name=”EnableHtmlAccess” value=”false” /> tag is present in the object tag, the DOM bridge will not work and the media player template will end up throwing an exception while trying to access the HtmlPage.Document.DocumentUri property.

The quick fix

Inside your Silverlight plugin object tag, add the EnableHtmlAccess parameter with a value of ‘true’. Here is a sample embedded object tag with the parameter added:

<object data=”data:application/x-silverlight-2,” type=”application/x-silverlight-2″ width=”685″ height=”448″>
     <param name=”source” value=”http://media.cdn.com/Xaps/MediaPlayerTemplate.xap” />
     <param name=”initparams” value=”expression encoder generated parameters go here” />
     <param name=”enableHtmlAccess” value=”true” />
</object>

The source fix

I decided to just update the media player to not be dependent on the HTML DOM bridge feature.

This fix assumes that you always provide the absolute URI for video assets in the playlist. Effectively it won’t try any relative URI lookups when HTML DOM bridge access is not permitted.

Thanks to the Expression team, they did a good thing and shipped the source to the media player template with the product. You will find it in %programfiles%\Microsoft Expression\Encoder 2\Templates\en\SL2Standard\Source. It opens with Visual Studio 2008 SP1 + the Silverlight 2 Developer Tools.

I went ahead and rebuilt the template: whenever the C# code would try and use the HtmlPage.Document.DocumentUri getter, I would encase the code in an HtmlPage.IsEnabled check. I had to do this in just a few spots.

One nice side effect was that I was able to chop the .Xap size down about 50K by removing the Adaptive Streaming support built into the template, since I just host my media assets over simple HTTP and do not do streaming.

For your reference:

Download ModifiedTemplate.zip (69 K, solution in a Zip)
Download MediaPlayerTemplate.xap (114 K, Xap)
Note: Does not contain adaptive streaming support.

HtmlPage.IsEnabled lesson

You should always make sure to check the HtmlPage.IsEnabled property before attempting to access any of the HTML DOM bridge resources. This is good practice whether thinking about scenarios where the bridge is disabled, or designer tools like Cider and Blend.

Disclaimer: I am not a member of the Expression team, this is not my area of expertise, other than being a member of the original HTML DOM bridge feature crew for Silverlight. I do not know if this was a known issue before, an expected, by-design feature, will be fixed, or anything like that.

Live, embeddable player: Shawn Burke’s PDC talk

Oh, and here’s Shawn Burke’s excellent PDC talk. If you haven’t checked out everything that was released in the Silverlight Toolkit, or heard about the release model, you should watch this. It is using my updated Xap player, so you can even embed Shawn’s talk in your own blog.

Hope this helps.

I’m also publishing an introductory guide to the control that can be read here.

Duration: 12m:55s
Description: This video walks you through the AutoCompleteBox control and its samples that shipped with the Toolkit.

Contents:

• Advanced scenarios
• Basic examples
• The core AutoCompleteBox behavior properties
• Running the unit tests

Take this video on the road:
Download for Zune (WMV, 46MB)
Download for iPod/iPhone (M4V, 26MB)
Download for Windows Media Player (WMV, 107MB)

See also:
Introducing the AutoCompleteBox
AutoCompleteBox: The 5 things you need to know

p.s. This Silverlight 2-powered video was encoded using Expression Encoder 2 Service Pack 1 that was just released today.

I’m going to try and make any future screencasts come in under 5 minutes.

In this video I introduce the control source and unit test announcement from MIX, and then walk you through:

• exploring the Silverlight 2 Beta 1 control source code, unit test and unit test framework download
• using Visual Studio 2008 to run the control unit tests
• adding the Exclusive attribute to narrow the test(s) that run in the browser when analyzing tests
• running the tests in Firefox
• running the tests in Expression Blend 2.5

I hope you find this useful, I’m planning on screencasting a more in-depth look at the test framework in the future.  I’ll try and enunciate a little better next time, the audio could have been clearer.

Speaking of video, don’t forget that all of the sessions for the MIX conference are online at http://sessions.visitmix.com/.