Binding in flex has been playing on my mind for a little while now, so I have decided to finally sit down and try to resolve the issue.

The worry has been that on large projects that make heave use of the flex automatic binding, compile times could be dramatically increased. This is because behind the scenes the flex compiler must convert those syntax sugar ([Bindable] and {}) into actual AS3 code. The exact way this is done I wont go into, but I recommend you google it, its a fascinating topic.

I really like the ease of use of automatic binding but at the same time I was worried about how much slower compile times are because of them. So I decided I would try to run some tests and see.

To compare the compile time performance of binding I ran three tests. The first, a control to define how long compilation takes with an empty Flex Application. The second tests how long non-binding takes and is comprised of a single group with 4000 labels that are assigned values. The third test is for binding and is 4000 labels that are bound to 4000 [Bindable] public variables.

For testing metrics I used the -benchmark=true compile flag along with -incremental=false to stop any sort of compile-caching. The full command line compile looks like:

“E:\Program Files\Adobe\Adobe Flash Builder 4\sdks\flex_sdk_4.5.0\bin\mxmlc.exe” -load-config+=MainConfig.xml -debug=true -incremental=false -static-link-runtime-shared-libraries=true +configname=air -benchmark=true

I ran each test three times and took the average of each. I then ran the entire thing again but with -debug=false to see if that would make any difference.

I recorded all the results in this google doc: https://spreadsheets.google.com/ccc?key=0AoHeesrTENc9dEFqamdCc2ZldHcyZkJmQkZsaDBOT0E&hl=en&authkey=CLP8r-MF

The general gist is that it seems binding adds about 20% onto compile times both- debug=true and -debug=false. This isnt as bad as I was fearing but still a 20% increase on a 30 second compile time can be annoying.

Im not sure if the tests I did were fair so I would love to hear feedback from others.

I have bundled the project up incase anyone wanted to test it themselves: http://mikecann.co.uk/wp-content/uploads/2011/02/CompileTestGen.zip

Came across this little oddity the other day. Took me ages to work out what was going on, so thought I would share in case anyone else ran into the same issue.

One day, for a reason I couldn’t fathom, my project stopped compiling. I kept getting these odd “1046: Type was not found or was not a compile-time constant” errors all over the place. Not only that, when I tried to include the class in question either via auto-complete (control & space) or via manual import the error persisted.

To cut a long story short it seems that if you try to new a member property that is of type Class from another class and the constructor takes in at least one parameter the error will occur.

So for example take the two following classes:

Source code

package package2
{
	import package1.MyTestClass;
 
	public class MyTestClass2
	{
		public var type : Class = MyTestClass;
	}
}

And

Source code

package package1
{
	public class MyTestClass
	{
		public function MyTestClass(someVar:String)
		{
			trace(someVar);
		}
	}
}

Now try using them in the following fashion:

Source code

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
			   xmlns:s="library://ns.adobe.com/flex/spark"
			   xmlns:mx="library://ns.adobe.com/flex/mx" creationComplete="application1_creationCompleteHandler(event)">
 
	<fx:Script>
		<![CDATA[
			import mx.events.FlexEvent;			
 
			protected function application1_creationCompleteHandler(event:FlexEvent):void
			{
				var class2 : MyTestClass2 = new MyTestClass2();
				var class1 : MyTestClass = new (class2.type)("hello");
			}
 
		]]>
	</fx:Script>
 
</s:Application>

And uh oh, bad times:

Source code

1046: Type was not found or was not a compile-time constant: MyTestClass.	FlexBugExperiment.mxml	/FlexBugExperiment/src/main	line 14	Flex Problem
 
1046: Type was not found or was not a compile-time constant: MyTestClass2.	FlexBugExperiment.mxml	/FlexBugExperiment/src/main	line 13	Flex Problem
 
1180: Call to a possibly undefined method MyTestClass2.	FlexBugExperiment.mxml	/FlexBugExperiment/src/main	line 13	Flex Problem

The bad line is:

Source code

var class1 : MyTestClass = new (class2.type)("hello");

If you take away the “hello” part or you split it out into two lines like so:

Source code

var tmpC : Class = (class2.type);
var class1 : MyTestClass = new tmpC("hello");

Then everything is gravy

Anyway, I hope this helped someone out!

Have you ever wanted to have multi-line text in your label component in spark and thought the following should work?

Source code

<s:Label text="I like text on the \n next line" />

But all it produces is:

Yep me too.

After some playing however I stumbled accross the following solution:

Source code

<s:Label text="I like text on the {'\n'} next line" />

It then produces the expected result:

Im just guessing but I suspect its something to do with the black art of the flex life cycle. By adding the {‘\n’} we are turning the property initialisation on the label component from a simple literal assignment into a delayed binding assignment and therefore gets parsed differently.

Just a guess, let me know if im way off.

I have called it Scribble and its very basic at the moment, not containing even many of the simple features in Harmony, I do however intend to keep adding to it. So over the course of several weeks I hope to add bit by bit till it becomes a fun little place to Scribble!

Anyways, you can check out the current state of the thing here –> http://www.mikecann.co.uk/flash/Scribble_v0-1/Scribble.html

Splendid!

(click to enlarge)

I love the Trance Around The World radio show by Above and Beyond, downloading  it for listening later is very annoying however and involves some fiddling with browser source and other things, so to make life easier I built this little tool. What it does is grab the HTML from the above and beyond page then parse it for the MP3 file, then it uses the FileReference class in flash to download it to your HD.

Anyways, enough jibber jabber. Source is enabled:

Hope you enjoy!

For a while now (alot longer than I had hoped for) I have been working on a project that falls outside the realms of my usual kind of games-related projects. Im not ready do describe exactly what it is yet but im excited about it.

For months I have been struggling with the techinal challenges the project has entailed and I have dabbled with many new and highly diverse technologies including JavaFX (Java), Qt (C++) and Mono (C#).  I have been looking for a cross-platform technology that will get the job done that I need and doing it in an elegant manner.

I thought I had found it with a combination of JavaFX and straight Java using the PureMVC framework. I however was plagued with problems throughout with Bonjour, jGroups, JmDNS, JNI and JNA.

So after months of work, hardship and struggles I read a very interesting article on the up-and-coming Adobe AIR 2.0  that was opened for beta in December. With 2.0 Adobe are bringing NativeProcess  to Air. What this means is that you can you can execute native code (.dlls, .so, .jar etc) from Air. To me this was bloody brilliant as I had been playing with Air reccently and my day-job heavily involves Flex and I simply love the power and beauty of Flex.

So what this meant to me was that I could write the bulk of my project including its interface in my much preferred Adobe Flex (Air) and then use Native Process to communicate with a small kernel of Java that would do all the dirty work that Air itself cant do.

So after a little playing with Flerry for Air->Java bridge I started to think about the structure of the code and the framework I would use. For my initial few runs at this project I had been using the Java version of PureMVC. I really like some aspects of PureMVC but I think its can be so overly cumbersome in some circumstances (ill write another post on this in the future I think). So instead I looked at the alternatives.

I have been using Mate alot recently at work and on my own mini-project the Audio Book Organiser. However as this project is partly for my own learning and personal growth I decided to look at what else there was out there. From the videos by Jessie Warden I had heard about Robot Legs. Apparently this framework has been around for a while, but it was the first I had heard of it. Taking at look at it I immediately became very excited as it looks like it offers all the things that make PureMVC great but without the extra coding-baggage that goes with it.

To add to my interest it appears another very interesting, very new action-script technology has been introduced into Robot Legs called Signals by Robert Penner. Signals is an alternative to the standard events dispatching method found throughout flash (more on this in another post).

So why have I called this post “the bleeding edge?”. Well Adobe Air 2.0 is still in beta and has only been for a month or so. Its so new that some parts still havent been documented atall and the only way to find out how they work is to post a msg to the devs on the forums. Signals is also new and its integration into Robot Legs is very new indeed (last coupple of weeks). So at the moment I feel as if im at the forefront of some very new, very exciting technology, a stark contrast to my fiddlings with the ancient Java.

I realise this post is very text and tech-heavy but I needed to post about it before I forgot all the pain I have gone through with this project to get where I am at the moment. Future posts ill be delving a little deeper into some of my experiments with these new technologies

Thought id mention these videos as I have been watching them and really like the content. They are a series of video blog posts by one of the ‘celebrities’ of the Flash and Flex world, in which he talks about lots of stuff related to whats going on in the industry and the various frameworks he uses or recommends (or doesnt). He also has a few things to say about beer, which is a bonus!

Anyways theres three of them so far, and can be watched over on his blog:

1 vs Many, Mediator vs Presenter, 30 mins – JXLTV – Episode #1
Conferences, Why Frameworks, Cairngorm 3 – JXLTV – Episode #2
Apple’s iPad, HTML5 Video, Gaia Flash Framework – JXLTV – Episode #3

Well I was just doing some audio book organising and realised that it would be great if I could drag and drop a folder straight from my AIR into iTunes ready for upload to my iPhone.

Anyways after a little searching through the docs I came up with this little ditty:

var cp : Clipboard = new Clipboard();
cp.setData(ClipboardFormats.FILE_LIST_FORMAT, [new File(book.url)], false);
NativeDragManager.doDrag(null,cp);

<mx:DataGrid width="100%" height="100%" dataProvider="{books}" editable="true"
  itemEditEnd="{dispatchEvent(new BooksEvent(BooksEvent.PROPERTY_CHANGED));}"
  dragEnabled="true"
  dragStart="{dispatchEvent(new BooksEvent(BooksEvent.BOOK_BEGIN_DRAG, AudioBookModel(event.currentTarget.selectedItem)))}">

Just did a quick update to the audio book organiser. Added the ability to move the storage database file. This was so that I can put my storage file on Dropbox and it will then be backedup and synced between machines.

New version and sources:

Source: http://www.mikecann.co.uk/flash/AudioBookOrganiser/AudioBookOrganiser_v120_source.zip