I'm not worthy :)
On Wed, Aug 13, 2008 at 6:42 PM, Josh McDonald <[EMAIL PROTECTED]> wrote:
> Cummon, that's like 15 lines of code, ya bum :)
>
> this is written in gmail, not builder. YMMV. And change it to use weak
> referenced listeners, too.
>
> public class ObserveCollection
> {
> private var watching:ICollectionView;
> public var handler:Function;
>
> public function set source(value:ICollectionView) : void
> {
> if (watching)
> watching.removeEventListener(CollectionEvent.CHANGE, changed);
> watching = value;
> watching.addEventListener(CollectionEvent.CHANGE, changed);
> changed();
> }
>
> private function changed(ignored:*) : void
> {
> if (handler != null)
> handler();
>
> }
> }
>
> On Thu, Aug 14, 2008 at 11:05 AM, Richard Rodseth <[EMAIL PROTECTED]>wrote:
>
>> 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?
>>>
>>>
>>>
>>>
>>
>
>
> --
> "Therefore, send not to know For whom the bell tolls. It tolls for thee."
>
> :: Josh 'G-Funk' McDonald
> :: 0437 221 380 :: [EMAIL PROTECTED]
>
>
