André, by "node" I mean an object of LzNode, which cannot have any
view children, since the functionality to add subviews is missing. So
I'm talking strictly about a structure like this:
<canvas debug="false">
<node>
<view />
</node>
</canvas>
For the DHTML runtime, you'll get a JavaScript error in
LaszloView#__LZinstantiationDone ():
/**
* Called when the view itself and all its children have finished
* instantiating.
* @access private
*/
override function __LZinstantiationDone () : void {
var vip:LzView = (this.immediateparent cast LzView);
if (vip) {
(vip).addSubview( this );
}
super.__LZinstantiationDone();
}
In that case, in DHTML runtime a call is made to addSubview(), which
of course fails since LzNode doesn't own that function.
On Fri, Jan 28, 2011 at 5:35 PM, André Bargull <[email protected]> wrote:
> We cannot emit a compile-time warning due to possible dynamic placement
> changes at runtime. For example a <node> may contain several <view>s, but in
> its determinePlacement() method, the <node> will change the immediate-parent
> for the <view>s, so they're properly attached to another <view>.
>
> Simple example to underline my concern:
> <canvas>
> <class name="mynode" extends="node" defaultplacement="whatever">
> <method name="determinePlacement" args="aSub, placement, args" >
> return canvas;
> </method>
> </class>
>
> <mynode>
> <!-- the view will be attached to the canvas -->
> <view width="50" height="50" bgcolor="blue"/>
> </mynode>
> </canvas>
>
>> Guess the compiler would have to throw an error when a subclass of
>> node uses a mixin which contains views. But then, I just realize that
>> the compiler doesn't warn if you add a view to a subclass of node when
>> not using a mixin. What should the compiler do in such a case?
>>
>
>
> Yeah there ought to be a warning either at compile time if possible or at
> runtime
> if a view is a child of a non-view parent. Perhaps in debug mode we could
> have a runtime check. File an improvement request in Jira?
>
> --
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com
>
>
