UIObject.createClassObject()

Comments

Dennis O'Brien said on Feb 25, 2009 at 7:42 PM :

If you try the examples here from a class that extends MovieClip, you will need to either make your class dynamic, or make it extend mx.core.UIObject.

Just burnt an hour on this, so I thought I'd share.

To reproduce:
1) Make a new AS2 fla. Save it somewhere.

2) Drag a Button symbol from the Components panel to your library.

3) Create a new movieclip in the library.
call it mcScreenWithButtonComponent
export for AS
id: mcScreenWithButtonComponent
Class: MCScreenWithButtonComponent

4) Create the class file MCScreenWithButtonComponent.as in the same folder as the fla.
// begin
import mx.controls.Button;
import mx.core.UIObject;

class MCScreenWithButtonComponent extends MovieClip
{
public var btn:MovieClip;

function MCScreenWithButtonComponent()
{
createClassObject(mx.controls.Button, "btn", this.getNextHighestDepth(), {label:"Test Button"});
}
}
// end

5) On the first frame of the fla, instantiate the class.
_root.attachMovie("mcScreenWithButtonComponent", "mcScreen", this.getNextHighestDepth());

6) Compile. The Compiler Errors dialog display: "There is no method with the name 'createClassObject'."

7) Make your class dynamic:
dynamic class MCScreenWithButtonComponent extends MovieClip
Or, change the class to extend mx.core.UIObject instead of MovieClip.
class MCScreenWithButtonComponent extends mx.core.UIObject
No compile problem, and the button appears.


I've been bitten by not including the dynamic keyword many times, but this one was not so obvious.