Archive for January, 2011

as3term – Handy app for compiling AS3 snippets

January 21, 2011

I found a cool little Air app on for compiling and executing simple snippets of AS3 code.

Very handy for testing out things like Math functions.



Flash Builder 4, Flex 3 SDK: Export Release Build Error

January 19, 2011

Had to import some Flex 3 projects to Flash Builder 4 (using it in work now), and everything seemed to go ok. Had copied the Flex 3 SDK from FB3 folder, set it as the default in FB4. Cleaned and ran the project (including RSL library projects) all ok. Then went to Export Release Build and got:

Error – One or more errors were found while trying to build the release version. Unable to export.

The Log file (thanks to doc_180 on Stackoverflow) showed the cause as:

java.lang.NoClassDefFoundError: flex2/tool/oem/OEMException$CircularLibraryDependencyException

Log file can be found at the equivalent of C:\Documents and Settings\bbishop\Adobe Flash Builder 4\.metadata

Turns out that 3 files are required by Flex 3 SDK to export a release build in Flash Builder 4 where RSL’s (Library projects) are used, and these are missing. Luckily you can copy these from the Flex 4 SDK.

Let me shout out a thanks to eggsWurzel for his Adobe Forum Post with the solution. Bug is on the Adobe Jira Bug Database

How to implement the solution

  1. Get a copy of flex-compiler-oem.jar from C:\Program Files\Adobe\Adobe Flash Builder 4\sdks\4.1.0\lib
  2. Extract flex-compiler-oem.jar (using Winzip/7 Zip/Winrar), and go to the flex2\tools\oem folder in the extracted files
  3. Look for the following 3 files:
    1. OEMException$CircularLibraryDependencyException.class
    2. OEMException.class
  4. Open Winrar (doesnt work for me with Winzip or 7 Zip), and in the AddressBar browse to the flex-compiler-oem.jar file in the Flex 3 SDK – should beequivalent to C:\Program Files\Adobe\Adobe Flash Builder 4\sdks\3.2.0\lib (make a copy first just in case), and open \flex2\tools\oem
  5. Drag the 3 OEM files over to the \flex2\tools\oem folder in Winrar

That’s it! Close Winrar, and restart Flash Builder 4, should Export a release build ok now:) Nice one.

Note: if using RSL’s you may also need to untick Use local debug runtime shared libraries when debugging from Flex Build Path>Library Path

App Size: Flex vs Actionscript Project (Flex Framework Caching)

January 14, 2011

Following on from discussions at the ‘after’ part of last nights MMUG-Dublin meeting, I created a pure Actionscript 3 project and a similar Flex application project, both in Flex Builder 3. The aim was to compare final swf size. Both apps draw 3 circles on the screen.

Three circles, well done

Size Wise:

Flex 3 Application SWF (Release Build of Project): 169KB (but only 65KB with framework caching – see Optimization section below)

Pure Actionscript 3 Project SWF: 1KB

Optimization – Framework Caching

By default, the flex framework gets merged into your main swf file, adding around 100KB+. This can be avoided by going to Properties/Flex Build Path/Library Path/Framework Linkage/ and selecting Runtime Shared Library (RSL) from the dropdown. When you do a Build Release Project, your framework will be exported as a signed swz and an unsigned swf . These files should be placed in the same directory as your main swf file on the web server. In Flex 4, the framework RSL will automatically point to a public section of the Adobe site, where the swz’s will be available. Saves you having to host them.

The framework will only need to be downloaded by a particular client once, and will be cached by Flash Player, meaning every subsequent use of your app will not require downloading of the framework.swz (in the release will be named something like framework_3.2.0.3958.swz).

Read more about framework caching here:


If Actionscript will suffice e.g. for drawing three circles on the screen, go with a pure AS3 Project. If your developing data driven applications and user interfaces, use the Flex SDK (saves a tonne of time and effort, and whats 60kb these days – less than most peoples profile pics). Have a look at this Stackoverflow question for more opinions on each approaches pros and cons.



<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="" layout="absolute"
			import mx.core.UIComponent;

			private function onInitialize():void{
				drawCircle( 0x336699 );
	            drawCircle( 0x993333 );
	            drawCircle( 0x339933 );

			private function drawCircle( color:uint ):void
	            var circle:Shape = new Shape();
	            var displayObject:UIComponent = new UIComponent();

	   color );
	   2, 0xCCCCCC );
	   30, 40, 30);
	            circle.x = (this.numChildren * 65) + 10;
	            circle.y = 0;


Actionscript Project

package {
	import flash.display.Shape;
	import flash.display.Sprite;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;

	public class ActionScriptProject extends Sprite
		public function ActionScriptProject()
			stage.scaleMode = StageScaleMode.NO_SCALE;
            stage.align = StageAlign.TOP_LEFT;
            doDrawCircle( 0x336699 );
            doDrawCircle( 0x993333 );
            doDrawCircle( 0x339933 );

		private function doDrawCircle( color:uint ):void
            var child:Shape = new Shape();
   color );
   2, 0xCCCCCC );
   30, 40, 30);
            child.x = (this.numChildren * 65) + 10;
            child.y = 0;


Module Optimization: Link report and load externs

January 12, 2011

When modules are released or built (using Clean or Project>Export Release Build..), the exported module swf’s will include any Flash/Flex framework classes and external swc/swf classes that are used by the modules.

This is not always optimal, as some of the files included in the Module’s swf’s may already be in used by the Main app, and included in the MainApp.swf. You can remove the overlapping classes from the module swf’s by doing the following:

  1. In your main app i.e. the one that will use the module, go to Project>Properties>Flex Compiler and add an Additional compiler arguments:


  1. Clean or Export Release Build the project.
  2. Copy the link_report.xml file from the bin-debug or bin-release folder and paste it to the root of the module project folder i.e. the same folder as the Module.mxml file(s).
  3. Repeat step 1 for the Modules project, and add the compiler arguments:


  1. Clean or Export Release Build the project.

The released module swf’s will not include any external files that it shares with the main app. Reduced the size of the module I was optimizing in work by 15%!

Additional Compiler Arguments

More details on the compiler arguments and module optimization from:

Caution: any time you change your main app, and remove or change dependencies or SDK versions, you will need to repeat the above process. The modules will not work with apps that they have not been optimized for.

If you receive an error message -load-externs “could not open …..”, make sure that the xml file is at the root of the module project.