I think I may have an answer. I broke down the code into its constituent
pieces and I now have a theory.
My theory:
When you use (data as TestObject).b, you are actually trying to bind to
the data property of the item renderer. As this is not a bindable
property, you get the error. When you use the cast: TestObject(data).a,
you are now binding to TestObject which does have bindable properties.
Have a look at the following code...
TestObject.as
package
{
public class TestObject
{
[Bindable] public var item1:uint = 2;
[Bindable] public var item2:uint = 3;
[Bindable] public var item3:uint = 1;
}
}
HBoxItemRenderer.as
<?xml version="1.0" encoding="utf-8"?>
<mx:HBox xmlns:mx="http://www.adobe.com/2006/mxml";>
<mx:Script>
<![CDATA[
[Bindable] private var theTestObject:TestObject;
override public function set data(value:Object):void
{
super.data = value;
if(value != null)
{
theTestObject = data as TestObject;
}
}
]]>
</mx:Script>
<mx:Label text="{theTestObject.item1}"/>
<mx:Label text="{theTestObject.item2}"/>
<mx:Label text="{theTestObject.item3}"/>
</mx:HBox>
DataBindingTest.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml";
layout="absolute">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
[Bindable] private var d:ArrayCollection = new ArrayCollection([
new TestObject,
new TestObject,
new TestObject
]);
]]>
</mx:Script>
<mx:List dataProvider="{d}" itemRenderer="HBoxItemRenderer" />
<mx:Button click="for each(var o:TestObject in d) { o.item1++;
o.item2++; o.item3++ }"/>
</mx:Application>
If anyone thinks my theory is incorrect, please chime in.
HTH
Steve
--- In [email protected], Pan Troglodytes <chimpathe...@...>
wrote:
>
> Well, I entered the two related issues as:
>
> https://bugs.adobe.com/jira/browse/SDK-21100
> https://bugs.adobe.com/jira/browse/SDK-21101
>
> Maybe someone at Adobe can manage to reproduce them. I'm not really
sure
> how much harm is being done, since the code appears to work right in
the
> end. But someone weird and unexpected seems to be going on under the
hood.
>
>
> On Tue, May 12, 2009 at 2:39 PM, Pan Troglodytes
[email protected]:
>
> > Thanks for giving me some confirmation. Now if we could just figure
out
> > what Alex/Adobe need to do to replicate our tests.
> >
> > The reason it doesn't give a warning on "y" is due to what I
referenced
> > (perhaps unclearly) above. Notice in the warning it tells you it
can't bind
> > to that value on the *itemRenderer *(GenericTest_inlineComponent1 in
my
> > test), not on the *TestObject* instance. The itemRenderer has an x
and y
> > object, so that's why it doesn't complain. It doesn't make any
sense that
> > it should be looking at binding to the itemRenderer instead of the
> > TestObject instance, though.
> >
> >
> > On Tue, May 12, 2009 at 12:24 PM, valdhor [email protected]:
> >
> >>
> >>
> >> Jason
> >>
> >> As a sanity check I tried it and I get the exact same error. I am
using
> >> Flex SDK 3.3.0 and Flash Player WIN 9,0,159,0 Debug.
> >>
> >> Strangely enough, changing b to y fixes it and the error goes away.
Other
> >> variable identifiers I have tried (Very small sample) gives the
error as
> >> well.
> >>
> >> It's got me beat.
> >>
> >> Why would the posted code give an error at all?
> >>
> >> Why would y work and everything else not?
> >>
> >>
> >> --- In [email protected] <flexcoders%40yahoogroups.com>,
Pan
> >> Troglodytes chimpathetic@ wrote:
> >> >
> >> > I wonder if I wasn't clear enough on this - these are run-time
warnings
> >> that
> >> > output to the console. You don't get those?
> >> >
> >> >
> >> > On Mon, May 11, 2009 at 5:27 PM, Alex Harui aharui@ wrote:
> >> >
> >> > >
> >> > >
> >> > > I didn't get any warnings like you did so I couldn't
investigate
> >> further.
> >> > >
> >> > >
> >> > >
> >> > > Alex Harui
> >> > >
> >> > > Flex SDK Developer
> >> > >
> >> > > Adobe Systems Inc. <http://www.adobe.com/>
> >> > >
> >> > > Blog: http://blogs.adobe.com/aharui
> >> > >
> >> > >
> >> > >
> >> > > *From:* [email protected]
<flexcoders%40yahoogroups.com>[mailto:
> >> [email protected] <flexcoders%40yahoogroups.com>] *On
> >> > > Behalf Of *Pan Troglodytes
> >> > > *Sent:* Saturday, May 09, 2009 10:38 PM
> >> > > *To:* [email protected] <flexcoders%40yahoogroups.com>
> >> > > *Subject:* Re: [flexcoders] using "as" breaks data binding?
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > 3.3.0. I also get it with 4.0.0.6137. Just downloaded and got
it in
> >> > > 6772, too. I'm using player version 10,0,12,36. Do you need to
know
> >> > > anything about my Flex Builder version? Let me know anything
else I
> >> can
> >> > > provide.
> >> > >
> >> > > When you say you don't get it with the soon-to-be 3.4, what
exactly do
> >> you
> >> > > mean? You just don't get the run-time warning? Did you track
down why
> >> it
> >> > > would be okay with "x" and see if that's still doing whatever
weird
> >> thing it
> >> > > is in 3.4?
> >> > >
> >> > > On Sat, May 9, 2009 at 4:11 PM, Alex Harui aharui@ wrote:
> >> > >
> >> > >
> >> > >
> >> > > Which version of Flex? I don't get it on the latest builds that
will
> >> ship
> >> > > as 3.4
> >> > >
> >> > >
> >> > >
> >> > > Alex Harui
> >> > >
> >> > > Flex SDK Developer
> >> > >
> >> > > Adobe Systems Inc. <http://www.adobe.com/>
> >>
> >> > >
> >> > > Blog: http://blogs.adobe.com/aharui
> >> > >
> >> > >
> >> > >
> >> > > *From:* [email protected]
<flexcoders%40yahoogroups.com>[mailto:
> >> [email protected] <flexcoders%40yahoogroups.com>] *On
> >> > > Behalf Of *Pan Troglodytes
> >> > > *Sent:* Friday, May 08, 2009 11:06 PM
> >> > > *To:* flexcoders
> >> > > *Subject:* [flexcoders] using "as" breaks data binding?
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > I've run across some peculiar behavior and I am trying to
figure out
> >> if I
> >> > > should report it and if so, how exactly to explain it. Given
these two
> >> bits
> >> > > of code:
> >> > >
> >> > > *TestObject.as:*
> >> > > package
> >> > > {
> >> > > public class TestObject
> >> > > {
> >> > > [Bindable] public var a:uint = 2;
> >> > > [Bindable] public var b:uint = 3;
> >> > > [Bindable] public var x:uint = 1;
> >> > > }
> >> > > }
> >> > >
> >> > > *Main Application:*
> >> > > <?xml version="1.0" encoding="utf-8"?>
> >> > > <Application
> >> > > xmlns="http://www.adobe.com/2006/mxml";
> >> > > >
> >> > > <Script>
> >> > > <![CDATA[
> >> > > import mx.collections.ArrayCollection;
> >> > > [Bindable] public var d:ArrayCollection = new ArrayCollection([
> >> > > new TestObject,
> >> > > new TestObject,
> >> > > new TestObject
> >> > > ]);
> >> > > ]]>
> >> > > </Script>
> >> > > <List dataProvider="{d}">
> >> > > <itemRenderer>
> >> > > <Component>
> >> > > <HBox>
> >> > > <Label text="{TestObject(data).a}"/>
> >> > > <Label text="{(data as TestObject).b}"/>
> >> > > <Label text="{(data as TestObject).x}"/>
> >> > > </HBox>
> >> > > </Component>
> >> > > </itemRenderer>
> >> > > </List>
> >> > > <Button click="for each (var o:TestObject in d) { o.x++; o.a++;
o.b++
> >> > > }"/>
> >> > > </Application>
> >> > >
> >> > > If you run this application, you get the following warnings:
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > > warning: unable to bind to property 'b' on class
> >> > > 'GenericTest_inlineComponent1'
> >> > >
> >> > > There's a couple of things that stand out here. First, it
doesn't
> >> complain
> >> > > about properties "x" or "a". The reason it doesn't complain
about
> >> property
> >> > > "a" is that I used "TestObject(data).a" instead of "(data as
> >> > > TestObject).a". If you change it to the other way around, you
will get
> >> a
> >> > > warning on "a" as well. I find this rather bizarre, as I
thought there
> >> was
> >> > > no functional difference to the two, other than "as" returning
null if
> >> the
> >> > > object wasn't of the appropriate type rather than just erroring
out
> >> like
> >> > > straight type coercion does. But type coercion/as are very
(ahem)
> >> "lightly"
> >> > > documented so I admit I don't know a lot. But I don't think
it's
> >> because of
> >> > > the null problem, since you can replace it with
"TestObject(null).b"
> >> and it
> >> > > stops giving the warning.
> >> > >
> >> > > The second weird thing is that it doesn't complain about "x"
when
> >> using
> >> > > "(data as TestObject).x" like it does with a. As you can see,
it's
> >> claiming
> >> > > this error is on GenericTest_inlineComponent1. This is
significant
> >> > > because it appears that it's instead doing some binding to the
"x"
> >> property
> >> > > on the item renderer, which is *very* odd. You can try this
yourself
> >> by
> >> > > changing "x" to other strings. Ones where there is a property
of HBox
> >> named
> >> > > the same thing won't give you a warning. Others will.
> >> > >
> >> > > Yet for all this griping, it seems the data binding IS working.
If you
> >> > > click on the button, you'll see all the labels in the list
change as
> >> the
> >> > > data is being changed.
> >> > >
> >> > > So, anyone want to shed some light on these two behaviors?
> >> > >
> >> > > --
> >> > > Jason
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > > Jason
> >> > >
> >> > >
> >> > >
> >> >
> >> >
> >> >
> >> > --
> >> > Jason
> >> >
> >>
> >>
> >>
> >
> >
> >
> > --
> > Jason
> >
>
>
>
> --
> Jason
>
