I have been developing a fairly rich Silverlight application for the last couple of months that is meant to ultimately replace some of our existing UI.  This project has evolved from prototype to framework authoring to actual wire-frame implementations.  I have had a chance now to step back and create some small charting components for one of our existing pages.  A change of pace can be refreshing, and this one allows me to stay in Silverlight land yet spend about a week writing some production code.

There are a number of charting components available, many of them free.  I am going to take this opportunity to write my own from scratch since I really only need some simple pie charts.  I want to keep it small and simple, and yet learn from the experience.

I have run into a new situation with these small components that I had not encountered with the large application.  I need to pass “command line arguments”.  Or rather, I need to embedd some data in the HTML page for the Silverlight to pick-up and render.  This data will be the charting data.  As it turns out this is dead simple.  In the Silverlight object tag I simply include the initParams parameter with my data, comma-delimited:

  <object type="application/x-silverlight" width="100%" height="100%">
    <param name="source" value="ClientBin/MyChartingApp.xap"/>
    <!-- Command Line Arguments -->
    <param name="initParams" value="datum1=1,datum2=2,etc" />
  </object>

Then I read that data in during the application’s Load event:

  private void Application_Startup(object sender, StartupEventArgs e)
  {
    foreach (var key in e.InitParams.Keys)
    {
      var datum = e.InitParams[key];
      //do something with the datum
    }
  }

Pretty simple!  Now I just need to write some ASP.Net code to render out the desired HMTL, and I am all set.  Oh, that and write the Silverlight component.

Scott Gu and Co. have announced a few more items that are, well, kick ass.

• A new data tier technology that will allow developers to write data services, decorate those services with a client attribute, and your Silverlight project will automatically generate proxies for those data services.  This eliminates a lot of custom code I have written to do my WCF plumbing.
• Silverlight on the desktop on Mac and Windows!  Its pretty obvious they are going after Adobe Air here.  This gives Windows developers and easy-in to Mac desktop development.
• A Silverlight developer plugin for Eclipse on Windows and Mac.
• Blend 3 can import from Photoshop.  It provides granular control over importing layers from the Photoshop document.  Very nice!
• Blend 3, in general, looks like a huge improvement over Blend 2.

Scott Guthrie is on stage right now in Las Vegas and here are a few things he has mentioned about Silverlight 3:

• Utilization of the GPU on the client machine for graphics acceleration.
• Merged Dictionaries (I had to write one of these myself).
• Style inheritance.
• On-demand type download – I wrote this from the ground up for the current app I am building.  Its nice to see it bundled in with SL3.
• Gestures in Windows 7 – I don’t know if this will be available in Silverlight on all platforms…
• Playboy is putting all of its archives into a Deep Zoom powered site.  Oh, and Rolling Stone is too.