Flex name spaces

Controlling method access with name spaces


You could call a different version of calcTax method using the name space soprano with a double colon as shown

tax = Tax.soprano::calcTax();

package com.enron.namespaces {
public namespace soprano=”http://www.enron.com/namespaces”;
}

package com.enron.namespaces {
public namespace regular;
}


package com.enron.tax{
import com.enron.namespaces.*;
public class Tax
{
regular static function calcTax():Number{
return 3500;
}
soprano static function calcTax():Number{
return 1750;
}
}
}

Flex Stage Object

The Stage class represents the main drawing area.

For SWF content running in the browser (in Flash^® Player), the Stage represents the entire area where Flash content is shown.

For content running in AIR, each NativeWindow object has a corresponding Stage object.

Reference to Stage object is null until applicationComplete() event - thats where you typically should add any listeners to the stage object

Flex 3 to Flex 4

Features & Migration Guide from Adobe lists them all - pretty useful. Wonder why did not see this earlier

Flash Player 10 in Flex Builder 3.0.2

This is a good post which highlights the steps

 What we essentially gotta do
       a) Install sdk 3.2 & configure it
       b) Remove playerglobal.swc from the existing project build path libraries list and point to  Flash Player 10 playerglobal.swc file as a merged link.

      This file is is in C:\Program Files\Adobe\Flex Builder 3\sdks\3.2.0.3794\frameworks\libs\player\10

Flex Custom Components

A Great Tutorial  

Singleton in ActionScript!

This is how you'd go about creating a Singleton in ActionScript! Create another class within the same file but outside the package declaration - so that it can only be accessed internally:


package{
    public class Singleton{
        private static var _instance:Singleton=null;
        public function Singleton(e:SingletonEnforcer){
            trace(‘new instance of singleton created’);
        }
        public static function getInstance():Singleton{
            if(_instance==null){
                _instance=new Singleton(new SingletonEnforcer());
            }
            return _instance;
        }
    }
}
//I’m outside the package so I can only be accessed internally
class SingletonEnforcer{
//nothing else required here
}

Flex Javascript Integration

Flex Javascript Integration

ExternalInterface defines two especially important static functions:

• call( functionName:String, ... arguments ) - call a container function
• addCallback( functionName:String, closure:Function ) - expose a Flex function to the container 

Call Browser/JavaScript from ActionScript

// call a JavaScript function defined in the container page
   var result:String = 
      ExternalInterface.call( "doSomethingInJavaScript", arg1, arg2 );

The above ActionScript code could call the below JavaScript code in the container HTML page:

// a JavaScript function in the container HTML page
function doSomethingInJavaScript( arg1, arg2 )
   {
      // do something
      return "results for " + arg1 + " and " + arg2;
   }

Call ActionScript from JavaScript/Browser

public function init():void
   {
      // expose an ActionScript function to the container
      ExternalInterface.addCallback( "doSomethingInActionScript", doSomethingInActionScript );
   }
   
   // function now callable from JavaScript
   public function doSomethingInActionScript( arg1:String, arg2:Number ):String
   {
      return "result";
   }
 

The below JavaScript code can be used to call the exposed ActionScript 
function:

// get the Flex application (Flash object)
   var isIE = navigator.appName.indexOf("Microsoft") != -1;
   var flashName = "flashObjectName";
   var flashObject = (isIE) ? parent.Main.window[flashName] : document[flashName];
   
   if( flashObject )
   {
      // call the Flex application (Flash object)
      flashObject.doSomethingInActionScript( "arg1", 2 );
   }