A little more context. I'm working on a view that builds itself dynamically
(adding children to various containers) based on a description.
So suppose my view has a property called "description" which has a property
"things" that is the collection or array.
It's no great hardship to add a listener in the setter for description, but
I wish I could say something like:
<mx:WatchCollection source="{description.things}" handler="thingsChanged"/>
On Wed, Aug 13, 2008 at 5:51 PM, Alex Harui <[EMAIL PROTECTED]> wrote:
> There must be some nuance I don't get. What about:
>
>
>
> <mx:ArrayCollection collectionChange="myFunction" />
>
>
> ------------------------------
>
> *From:* [email protected] [mailto:[EMAIL PROTECTED] *On
> Behalf Of *Richard Rodseth
> *Sent:* Wednesday, August 13, 2008 5:28 PM
> *To:* [email protected]
> *Subject:* Re: [flexcoders] Observing collections
>
>
>
> Hi Alex,
>
> Observe is designed to be used in MXML (it's even billed as the "world's
> smallest tag") and that's how I use it.
>
> http://weblogs.macromedia.com/paulw/archives/2006/05/the_worlds_smal.html
>
> As it happens it doesn't implement IMXMLObject.
>
> In any case, since it uses regular binding expressions for the "source"
> property, I believe it has the limitation-by-design I referred to.
>
> On Wed, Aug 13, 2008 at 5:17 PM, Alex Harui <[EMAIL PROTECTED]> wrote:
>
> Never used Observe, but if it implements IMXMLObject or you subclass and do
> so, then you can use it in MXML
>
>
> ------------------------------
>
> *From:* [email protected] [mailto:[EMAIL PROTECTED] *On
> Behalf Of *Richard Rodseth
> *Sent:* Wednesday, August 13, 2008 4:16 PM
> *To:* [email protected]
> *Subject:* [flexcoders] Observing collections
>
>
>
> For some reason I have an aversion to adding event listeners in
> ActionScript, favouring binding expressions and the Observe tag from Adobe
> Consulting. Not sure how rational this is, but there you have it. Binding is
> just so damn elegant.
>
> However, collections are a problem. It seems that so often you want to
> update something if either the collection itself or its contents changes,
> and you don't really care about the details of the change.
>
> I suppose if you're a DataGrid watching its dataprovider you do care and
> can minimize updates, but in many of the use cases I've encountered, that's
> not the case - my observer is going to do something with the whole
> collection (or maybe I've just been lazy about exploiting possible
> optimizations).
>
> Is there anything like the Observe tag that can be instantiated in MXML and
> can trigger a function call on a COLLECTION_CHANGE event?
>
>
>
>
>
