title: How to invoke a "loose Xaml"-defined activity from another "loose Xaml"-defined activity?
body: <p>I have two "loose" XAML files, each declarativly defining composite activity which is composed of some custom (compiled) code-activities.</p>
  
  <p>Now, I would like the activity defined in the 1st "loose" Xaml to 'contain' the activity defined in the 2nd "loose" Xaml as of its steps.</p>
  
  <p>However, I have no clue how to 'glue' both activities together such that 1st activity will know to correctly load the activity from the 2nd Xaml.</p>
  
  <p>So when calling:</p>
  
  <pre><code>XamlXmlReader xr = new XamlXmlReader(@"FirstLooseActivity.xaml");
  ActivityBuilder ab = (ActivityBuilder)XamlServices.Load(ActivityXamlServices.CreateBuilderReader(xr));
  </code></pre>
  
  <p>I end up with a XamlObjectWriterException (after I loaded all relevant assemblies to my hosting app):</p>
  
  <pre><code>Cannot create unknown type '{clr-namespace:SecondLooseActivity}MyActivity
  </code></pre>
  
  <p>Since there is no Xlink support in MS, is there a way to do this at all?</p>
  
  <p>If not, what are my alternatives?</p>