Hello List,
when I recently thought about a way to get AS3 code to JavaScript I got
into a major concept problem related to Weak references. As maybe most
of you know weak references are not supported by JavaScript. However:
The current code using addEventListener() relies heavily on weak
references to not come in trouble with memory leaks. This is also a big
problem in other UI toolkits to my knowledge and other toolkits solve
this using destructors or completely inverse control logic. For example
in SWT you have to call:
Widget.dispose();
after you stopped using your widget. The destructor-approach is in
theory a lot faster than the weak reference approach because it doesn't
rely on a garbage collector but it comes with a lot of code-noise. The
other approach, to have it in a completely inverse control flow looks
like this:
class Component implements IUIEventHandler {
public function handleMouseEvent() {}
}
and handleMouseEvent is called from outside. All other approaches I know
are just derivations of these two concepts. This means to me: Any use of
weak Dictionaries and weak event listeners would need to vanish from the
Flex SDK to actually make it portable.
I just wanted to point that out. It might be interesting to a few.
And related to that two questions:
1) Does anyone know how browsers avoid memory leaks with
addEventListener ?
2) Would the Flex team be open to such a fundamental change in code-style?
yours
Martin
