Gordon, I must say when you look at it(instantiation), it's a very strong algorithm at that :)
It's also nice to know that the impact of calling new before the display list cares is really important for some component's performance. Peace, Mike On 4/30/07, Gordon Smith <[EMAIL PROTECTED]> wrote:
The generated class doesn't look like that. Instead, the MXML compiler creates a tree of UIComponentDescriptor instances in order to support a feature of Flex known as deferred instantiation. BTW, another reason that the children don't get created at 'new' time is that inherited styles aren't known until the component is attached to its ancestors by addChild(). - Gordon ------------------------------ *From:* [email protected] [mailto:[EMAIL PROTECTED] *On Behalf Of *bhaq1972 *Sent:* Monday, April 30, 2007 1:50 PM *To:* [email protected] *Subject:* [flexcoders] Re: creating instances, addChild question thanks for the input Gordon, When i think of creating mxml components, i'm thinking lazy/convenience programming. i want all the component and its children to be created. I can give the children some default values which i can then change after the 'new', if i wish eg My PrintView.mxml <mx:VBox backgroundColor='yellow'> <mx:Label id='contact' text='batman'/> <mx:PrintDataGrid id="printDG"/> </mx:VBox> in code - var printView:MyPrintView = new PrintView(); // change what i like printView.contact.text = 'spiderman'; etc. i thought the generated AS class would look like this class MyPrintView extends VBox { public contact:Label; public printDG:PrintDataGrid public MyPrintView() { super(); contact = new Label(); contact.text = 'batman' addChild(contact) //etc } } --- In [email protected] <flexcoders%40yahoogroups.com>, "Gordon Smith" <[EMAIL PROTECTED]> wrote: > > > when i create an instance of MyPrintView, its children are not > created. why is that? > > if you addChild() to the Application....they are created. why is that? > > The reason that components do not create their children immediately when > they are created is so that you can set properties after calling 'new' > and have these properties affect which children get created. For > example, > > var clock:Clock = new Clock(); > clock.mode = "analog"; > addChild(clock); > > The Clock would need completely different children if the mode were > "digital" instead of "analog". By delaying the creation of the children > until addChild(), the framework makes it possible to optimize which > children are created. > > - Gordon > > ________________________________ > > From: [email protected] <flexcoders%40yahoogroups.com> [mailto:[email protected] <flexcoders%40yahoogroups.com>] On > Behalf Of bhaq1972 > Sent: Monday, April 30, 2007 4:57 AM > To: [email protected] <flexcoders%40yahoogroups.com> > Subject: [flexcoders] creating instances, addChild question > > > > This question is very similar to a question someone else is asking > (may even be the same thing????) > > I've got a component called MyPrintView.mxml > > <mx:VBox> > <mx:Label id="contact"/> > <mx:PrintDataGrid id="printDG"/> > </mx:VBox> > > when i create an instance of MyPrintView, its children are not > created. why is that? > > if you addChild() to the Application....they are created. why is > that? > > <?xml version="1.0" encoding="utf-8"?> > <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml > <http://www.adobe.com/2006/mxml> " > initialize="startUP()"> > > <mx:Script> > <![CDATA[ > private function startUP():void > { > var printView:MyPrintView = new MyPrintView(); > trace(printView); > trace(printView.printDG, printView.contact); //both null > addChild(printView); > trace(printView.printDG, printView.contact); //both not null > > } > ]]> > </mx:Script> > </mx:Application> >
-- Teoti Graphix http://www.teotigraphix.com Blog - Flex2Components http://www.flex2components.com You can find more by solving the problem then by 'asking the question'.
