I am currently migrating our system from zk 3.6.4 to 5.0.8 and ran into a problem using the implicit componentScope object in a zul file. The following snippet of code illustrates the problem.

 
<toolbar >
	<toolbarbutton label="click me" onClick="alert(componentScope.get("key"))" >
		<custom-attributes key="SomeValue"/>
	</toolbarbutton>
</toolbar>

Running the code produces the following error:

 
Sourced file: inline evaluation of: `` alert(componentScope.get("key"));'' : Error in method invocation: Method get( java.lang.String ) not found in class'org.zkoss.zk.ui.ext.Scopes$DeferredScope' : at Line: 2 : in file: inline evaluation of: `` alert(componentScope.get("key"));'' : componentScope .get ( "key" )

The work around to the problem is to use self.getAttribute() instead of componentScope.get().

This code worked great under zk 3.6.4.