How can I add ActionScript 3 import statements to LZX class definitions with OpenLaszlo 5.0?

Question

I'm working on an OpenLaszlo application using the unreleased version of OpenLaszlo 5.0 (trunk). In one of my classes I need to import ActionScript 3 classes. What is the recommended way to add such import statements?

Answer 1

LZX supports the passthrough tag. The passthrough tag in turn has a when attribute, where you can specify a boolean expression, e.g. $as3 or $swf10:

<canvas debug="true"> 

  <class name="foo"> 
    <passthrough when="$as3"> 
      import flash.system.Capabilities; 
    </passthrough> 
    <handler name="oninit"> 
      if ($as3) {
        Debug.info(Capabilities.os);
      } else {
         Debug.info("flash.system.Capabilities can only be used in the SWFx runtime");
      }
    </handler>
  </class>

  <foo />

</canvas>

For the SWFx runtime, the import statement is then injected into the genereated ActionScript 3 class.