Calling functions / setting variables in loaded SWF

Question

You know how you can create a Movieclip object, add a
function or variable to it, then call that function or change that
variable from within the SWF that includes it? I wanna be able to
do that, only with SWFs that are loaded at run time.
My "main" SWF is simply a menu-type thing. The user clicks a
button in my MAIN.SWF, and the MAIN.SWF then loads the SWF that's
associated with that button, using the AS 3.0 prescribed
Loader()-URLRequest()-addChild() method that everyone always asks
about.
This works great. But now I've got some custom objects and
such (ie., not just strings) within my MAIN.SWF that I'd like to be
able to share with the loaded SWFs. Preferably, I'd like to use an
accessor-type function (ie.,
LoadedSWF.GiveMeTheCoolObject(MyCoolObject);), though at this point
I'm willing to hack into the object itself (ie.,
LoadedSWF.CoolObject.CoolField = MyCoolObject.CoolField;) if that's
what it takes.
I've tried just calling the functions and setting the fields,
but the AS 3.0 compiler doesn't care for that sort of nonsense on
it's generically-defined objects. Notice also that, at run time, a
call to LoadedSWF.hasOwnObject("GiveMeTheCoolObject") returns true.
So my big-brained colleagues, what's the magic?
In advance, thanks for the help!
Scott

Answer 1

Kglad,
quote:
Originally posted by:
kglad
from that error message it appears your function is expecting
a member of the MyCoolObject class, correct?
and MyCoolObject is not an instance of that class. so, you
need to fix that. ie, create a member of that class and use that
class member as the function parameter.
Heh, that's what the error message says all right. But the
object actually IS a MyCoolObject class object. I stared at this
thing for hours, and MyCoolObject IS an instance of that class. I
tried various casting combinations (including casting it to an
Object and passing that) but had no luck whatsoever.
So I googled this particular runtime error message ("Error
#1034: Type Coercion failed: cannot convert ") and found a ton of
links to other people having a similar issue. Typically, the
problem was just as you said, someone passing a button as a string,
that kinda thing. But one guy had a problem with an object he
derived from the Event class. After hours spent trying to get it to
work, he tried overriding the base class' clone() method and got it
to work:
http://www.asserttrue.com/articles/2006/10/14/custom-events-in-actionscript-3-0
As for my project, I took a long hard look at the overall
architecture of my project and decided that it was best if all the
"real work" took place in the MAIN.SWF file. This approach would
solve a couple of other problems, and it just makes sense in a
"separate the display from the data" mentality.
So (and this is the interesting part) I changed the API for
the LOADED.SWF to accept String pairs (ie.,
LoadedSWF.AddToDisplay(Name:String, Data:String) ) instead of
accepting MyCoolObj. Ran it, and Viola, now we're working without
any run time exceptions. After that glorious moment, I created a
couple of other APIs that just accepted base classes (one an int
type, the other a function type) and was happily on my way.
From this, I gather that passing non-base class (ie, derived
class) objects to loaded MovieClips via custom function APIs is...
maybe not as straightforward as we'd expect. In the grand scheme of
things though, not a big deal: As far as I'm concerned AS3 rocks.
Again Kglad, thanks for all the help: Your input on how to do
this was the big push that I needed to get over the last technical
hurdle of this project.
To those who are reading this topic for the "how do I call
functions and/or set variables in a loaded SWF?"
The short answer is to cast the loaded SWF's content object
as a MovieClip and then call the function or alter the variable:
//Load the SWF (you've seen this code a million times)
var LoadedSWFObj:Loader = new Loader();
var MyURL:URLRequest = new URLRequest("LoadThisSWF.SWF");
LoadedSWFObj.load(MyURL);
//This is within your Event.COMPLETE handler:
//Cast it as a MovieClip object and work with that.
var LoadedSWF:MovieClip = LoadedSWFObj.content as MovieClip;
// or another way to cast it is:
var LoadedSWF:MovieClip = MovieClip(LoadedSWFObj.content);
//Call yer function:
LoadedSWF.CallMe();