Thanks Alex, good info as usual.
Jason Merrill
Bank of America
GT&O L&LD Solutions Design & Development
eTools & Multimedia
Bank of America Flash Platform Developer Community
________________________________
From: [email protected]
[mailto:[EMAIL PROTECTED] On Behalf Of Alex Harui
Sent: Thursday, January 24, 2008 6:07 PM
To: [email protected]
Subject: RE: [flexcoders] chicken and egg object instatiation
The debugger reads every getter function in an object that is in
scope. This can cause getters to fire early before other things are
set. It doesn't happen to me often, but when I run into that, I just
add null tests and return null.
________________________________
From: [email protected]
[mailto:[EMAIL PROTECTED] On Behalf Of Paul Andrews
Sent: Thursday, January 24, 2008 3:00 PM
To: [email protected]
Subject: Re: [flexcoders] chicken and egg object instatiation
----- Original Message -----
From: Merrill, Jason
<mailto:[EMAIL PROTECTED]>
To: [email protected]
<mailto:[email protected]>
Sent: Thursday, January 24, 2008 10:52 PM
Subject: RE: [flexcoders] chicken and egg object
instatiation
Yeah, thanks, but what you've said is all the stuff I'm
already doing...
Well, it's about all I can suggest while debugging by proxy!
The notion of a 'parent' doesn't really exist for a network, so
I'm still not sure if this is really a tree.
If you have no values of parentAtom that are null, then maybe
you do have an unset value for id?
Maybe this is a classic where your array index count is one off
and the first or last value remains unset?
Basic stuff, I know (bites me all the time!)
Paul
Jason Merrill
Bank of America
GT&O L&LD Solutions Design & Development
eTools & Multimedia
Bank of America Flash Platform Developer Community
________________________________
From: [email protected]
<mailto:[email protected]> [mailto:[EMAIL PROTECTED]
On Behalf Of Paul Andrews
Sent: Thursday, January 24, 2008 5:47 PM
To: [email protected]
Subject: Re: [flexcoders] chicken and egg object
instatiation
Jason,
Presumably you're simplifying things. In a
network diagram, there may be several other connected atoms, so you'd
need an array of parentAtoms and it wouldn't be a parent relationship.
If you're really talking about a tree, then the
first atom won't have a parent and will be null.
When you create each atom, put a reference to it
in an array. When you think you've populated all the parentAtom
references, check them all by cycling through the array.
Somewhere, somehow, you must have a null
parentAtom value.
Sorry, not very helpful.
Paul
----- Original Message -----
From: Merrill, Jason
<mailto:[EMAIL PROTECTED]>
To: [email protected]
<mailto:[email protected]>
Sent: Thursday, January 24, 2008 10:38
PM
Subject: [flexcoders] chicken and egg
object instatiation
I have some AS3 code in Flex that
creates a series of objects (class instances) based on some data. It's
a network diagram being drawn dynamically. Each class instance object
(I call them "atoms") extends Sprite, has an id number property set in
it's constructor. Each atom instance has to reference (either directly
or by the id) another "atom" class instance so it knows what object is
it's "parent" (I have been careful to not actually use the keyword
"parent" but use other property names like atomParent) - this is so it
can draw a line to it on the screen and maintain a relationship. It's
kind of a chicken and egg thing, but I thought I had it solved by
creating all the "atom" object instances first, and then setting the
atom's parentAtom property to another atom instance later. That works,
however, FP9 Debug gives me the following error when I try and reference
a property on the atom's "parent" (i.e. atom.atomParent.id)
Cannot access a property or method of a
null object reference.
The thing I don't get is the parent
property (an instance of Atom) gets set right, if I trace it on an atom
instance, it shows:
[object Atom]
As I would expect. And the id property
on each atom gets set properly when the constructor runs. I've checked
the data too, all is well there. However, if I trace
myAtomInstance.parentAtom.id I get null, even though the constructor
should have already run on that object and set that id property.
How would you normally handle a
situation like this? I've tried several things, like breaking up the
methods that set, create atoms, and then set the parent property to run
via a timer, so the atoms are created, then the atom.atomParent is set a
second later and the atom.atomParent.id property is traced a second
after that, but it still comes up null. If you want the code details, I
think it's too much to post here, but I could post if you would like or
send offlist.
Jason Merrill
Bank of America
GT&O L&LD Solutions Design & Development
eTools & Multimedia
Bank of America Flash Platform Developer
Community
