This is pretty useful, though the same concept used to work before it only found its way into the documentation now. Hence I just wanted to share that information with you. Works really well.
<extension point="org.eclipse.ui.editors"> <editor class="<MyLanguageName>ExecutableExtensionFactory: org.eclipse.xtext.ui.core.editor.XtextEditor" contributorClass= "org.eclipse.ui.editors.text.TextEditorActionContributor" default="true" extensions="ecoredsl" id="org.eclipse.xtext.example.EcoreDsl" name="EcoreDsl Editor"> </editor> </extension>
Please not that MyLanguageName is actually the name of the factory you can find in your src folder of the UI-Project under your main package.
And now, if you'd like to write some ActionHandler for your xtext outline view, you can do just the same. Simply prefix the Handler class with the factory, and there you go!