Hmm... then how exactly is it that XMLNotifier does it? Or is the XML class use prototype-based inheritence?
And I'm definitely aware of AS3's true class-based inheritence... it's really the only way I can keep up with it (the prototype stuff always made my head spin a bit). I was just under the impression that they co-existed (or one piggy-backed on the other), but it make sense that there are VM optimizations for the non-dynamic stuff... Troy. On 12 Mar 2007 13:25:14 -0700, Gordon Smith <[EMAIL PROTECTED]> wrote:
Most Flex components (for example, the 'label' of a Button) are not implemented using prototype-based inheritance. AS3 added true class-based inheritance, and we use that because it has far better performance. The tradeoff for better performance is less dynamic behavior. In particular, with class-based inheritance you can't inject code at runtime. - Gordon ------------------------------ *From:* [email protected] [mailto:[EMAIL PROTECTED] *On Behalf Of *Troy Gilbert *Sent:* Monday, March 12, 2007 1:08 PM *To:* [email protected] *Subject:* Re: [flexcoders] Re: Data binding: How to detect data change has happened? Actually, wouldn't it be possible to watch any object by injecting code into the prototype to basically put yourself between a property set and the class's property set? From a brief glance at XMLNotifier, it looks like that's exactly what it does... Troy. On 12 Mar 2007 10:45:48 -0700, Alex Harui <[EMAIL PROTECTED]> wrote: > > When I mean general, it means that unless some one planned to allow > watching via ObjectProxy, then you can't find a way to watch it. > > > ------------------------------ > > *From:* [EMAIL PROTECTED] ups.com [mailto:[EMAIL PROTECTED] > *On Behalf Of *bruce1976 > *Sent:* Sunday, March 11, 2007 7:49 PM > *To:* [email protected] > *Subject:* [flexcoders] Re: Data binding: How to detect data change has > happened? > > > > I'd agree with everything that you said, except for the last portion: > > > There is no general property watching in AS, so you have to define > > contracts and use events and whatnot. > > Take a look at the ObjectProxy class, refenced below: > > http://livedocs.adobe.com/flex/201/langref/mx/utils/ObjectProxy.html > > By wrapping the object that you're interested in into an ObjectProxy, > you can get notified by any changes to the new object (just use your > new object in place of your old object). > > Regards, > > Bruce > > --- In [email protected] <flexcoders%40yahoogroups.com>, "Alex > Harui" <[EMAIL PROTECTED]> wrote: > > > > In the mx.controls.DataGrid, the dataProvider property is not a var, > it > > is a get/set function pair. When someone assigns dataProvider, the set > > function is called so we know it changed. > > > > > > > > All dataProviders must implement ICollectionView or will be wrapped in > > an ICollectionView. When you change things in an ICollectionView, the > > contract is the ICollectionView will spew events which the DataGrid is > > listening for. > > > > > > > > There is no general property watching in AS, so you have to define > > contracts and use events and whatnot. > > > > > > > > -Alex > > > > > > > > ________________________________ > > > > From: [email protected] <flexcoders%40yahoogroups.com>[mailto: > [email protected] <flexcoders%40yahoogroups.com>] On > > Behalf Of Greg McCreath > > Sent: Sunday, March 11, 2007 3:36 AM > > To: [email protected] <flexcoders%40yahoogroups.com> > > Subject: [flexcoders] Data binding: How to detect data change has > > happened? > > > > > > > > Hi all, > > > > > > > > I'm interested to know how in an object with a data binding I can > detect > > a change in the datasource. > > > > > > > > For example, if I were to develop (say) a custom datagrid that (in > MXML) > > a user of that datagrid can set the datasource property to something > > like "{blah.blahblah}". > > > > > > > > Then, in that custom datagrid how do I detect that that blah.blahblah > > has changed and take some action when it does? In the custom component > > I do not want to know of the existence of blah.blahblah, just that it > > has changed and what its new value is. > > > > > > > > All help appreciated. > > > > > > > > Greg. > > > > ________________________________ > > > > This email and any files transmitted with it may be confidential and > are > > intended solely for the use of the individual or entity to whom they > are > > addressed. This email may contain personal information of individuals, > > and be subject to Commonwealth and/or State privacy laws in Australia. > > This email is also subject to copyright. If you are not the intended > > recipient, you must not read, print, store, copy, forward or use this > > email for any reason, in accordance with privacy and copyright laws. > If > > you have received this email in error, please notify the sender by > > return email, and delete this email from your inbox. > > > >
