Skip to main content

Manually adding bindings between objects in Flex/AS3

I recently needed to manually create bindings in AS3 code between objects, and since MXML ultimately all is just AS3, I figured there had to be a way to do it.

<b>Binding in MXML</b>

Lets look at the following code...
<code>
    <mx:TextInput id="txtMyText?/>
    <mx:Label id="lblMyLabel? text="{txtMyText.text}"/>
</code>

Here you bind the text property of the TextInput to the label's text property so wh you type in the textInput, it reflects in the label.

<b>Binding in AS</b>

The key to this is a class called BindingUtils in the mx.binding.utils package. You can use this class as below:<more/>You have your components say in mxml as follows
<code>
    <mx:TextInput id="txtMyText? />
    <mx:Label id="lblMyLabel? />
</code>

Now you import the Binding utils and change watcher classes:
<code>
    import mx.binding.utils.BindingUtils;
    import mx.binding.utils.ChangeWatcher;
</code>

Then you use the bindProperty method to create the binding:
<code>
    private var watcher:ChangeWatcher;  
    watcher = BindingUtils.bindProperty(txtMyText,"text", lblMyLabel,"text");
</code>

This binds the txtMyText.text to lblMyLabel.text.

<b>Unbinding in AS</b>

Since we assigned the binding to a ChangeWatcher, we can then just stop watching it:
<code>
    watcher.unwatch();
</code>

I found this info very helpful and it makes coding with our Codex framework much more "flexible" (no pun intended).

Here are some good related links where I got some of this reference info:

<ul>
<li><a href="http://raghuonflex.wordpress.com/2007/08/30/binding-in-mxml-as/">http://raghuonflex.wordpress.com/2007/08/30/binding-in-mxml-as/</a>
<li><a href="http://raghuonflex.wordpress.com/2007/09/17/binding-and-unbinding-variables-in-as3/">http://raghuonflex.wordpress.com/2007/09/17/binding-and-unbinding-variables-in-as3/</a>
<li><a href="http://www.duzengqiang.com/blog/article.asp?id=460">http://www.duzengqiang.com/blog/article.asp?id=460</a>
<li><a href="http://weblogs.macromedia.com/auhlmann/archives/2006/09/using_binding_s.html">http://weblogs.macromedia.com/auhlmann/archives/2006/09/using_binding_s.html</a>
</ul>

Popular posts from this blog

Making Macbook Air with 128GB SSD usable with Bootcamp

I recently got a new Macbook Air 11" (the 2012 version) and loaded it with goodies like 8GB ram and 2GHz Core i7.  What I DIDN'T upgrade was the internal SSD.  My config came with 128GB SSD and I refused to pay $300+ to upgrade it to 256GB.  Yeah I know, some call me cheap, but SSds cost $75-$150 for 240GB, so adding another 128GB for $300 seemed way too steep for me.  I figured "ok, I'm going to make 128G work!"

Here is the story of how that went...

Installing python 3.4.x on OSX El Capitan

I love "brew" package manager, but sometimes being too progressive breaks things.  I have several python apps that I maintain that get deployed to AWS using Elastic Beanstalk.  AWS eb can deploy with python 2.7 or 3.4.  Any recent 'brew install python3" will get 3.5.1. #annoying

Dell XPS M1330 + Snow Leopard Hackintosh

I have been working with a Dell XPS M1330 laptop for a few years now.  It doesn't quite match up to the newest notebooks in terms of performance, but it certainly still has some life in it.  I had previously installed OSX 10.5.x on it as an experiment, and had moderate success.  I decided to revisit this idea again to install Snow Leopard (OSX 10.6) on the Dell M1330, and keep some notes for those of you brave enough to Hackintosh your own machine...