I do remember how the old LFC relied on silent errors. It made my
initial read of the source code unbelievably confusing until I
realized that referencing non-existent objects was expected behavior.
Kinda like nil in Objective-C, but not formalized. But I digress.
When you say "either use a closure or add a method to the sender,"
what does the closure option look like? Let's say I want to listen
for lz.Keys onkeydown events -- where would a closure fit into the
event propagation scheme? Do you just mean a dynamically created
trampoline created in code versus a static trampoline defined in markup?
Also: is there a JavaScript syntax for creating a standard function/
class that extends an AS3 class such as Eventable?
On Oct 29, 2009, at 4:01 PM, P T Withington wrote:
On 2009-10-29, at 16:40, Neil Mix wrote:
I understand why event senders would needs to be LzEventable, but
why event receivers?
Mostly this was because we had to rationalize the way events were
propagated when instances were created and constraints fired. It
turned out that a lot of that worked only 'by luck' in swf8 (with
the helpful feature that swf8 graciously ignored any errors like
calls to non-functions, evaluations of non-existent variables,
etc.) When we created the DHTML and swf9/10 back-ends, they were
not so forgiving. LzEventable encompasses the protocols that allow
an orderly evaluation of constraints.
It's not done yet, but this also was to reduce the need to manually
manage delegates. Delegates are a constant source of memory leaks
because they get forgotten and can end up "resurrecting" objects
that should have been collected. So, in swf8 and DHTML, we now warn
you, but in swf9/10 you will get a type error. Eventually, we hope
to be able to manage delegates completely internally to LZX.
Related: is there any way to trick the AS3 runtime into accepting
a dynamic POJSO as an LzEventable?
Usually when people run into this issue updating their code, they
can either use a closure or add a method to the sender that
trampolines to the non-LzEventable.
If you have a particular example, I can comment further.
