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on AIR Bus Tour Boston: ActionScript and JavaScript Integration

Kevin Hoyt is back with a second talk about how to integrate ActionScript with JavaScript within a single AIR application. Currently on the web you have an HTML page and throw in an embed to display some video, but it is a black box. Likewise a Flash application is mostly not interacting with HTML at all. Script bridging is the magic that makes it all possible.

He showed a simple Flex application with a location field that loads and displays an HTML page within AIR. Currently AIR can't display Flash embedded in an HTML page that it is rendering. That should be supported in a later beta.

AIR has a Flex tag called which can render HTML content. Primary use is to set the location property, which will load and display the URL given. He showed an AIR HTML "Browser" in 5 lines of MXML code:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical">
<mx:TextInput id="input" enter="web.location = input.text;"/>
<mx:HTML id="web" width="100%" height="100%"/>

In ActionScript you have full access to the HTML object and through it access to all JavaScript like functions such as getElementById. To read an HTML value in ActionScript:

// Read an HTML text field
var name:Object = web.javaScriptDocument.getElementById('txtName').value;
// Update an HTML text field
web.javaScriptDocument.getElementById('txtName').value = "text";

Data comes back as a JavaScript String, which doesn't map directly to an ActionScript String. The returned value should be stored as an Object. He didn't mention about gotchas when going in the other direction.

Next he showed how to use native drag and drop. The example took a desktop image and droped it on the Flex application. NativeDragEvent and friends let you handle the drag and drop. Once the Flex application got the image, it introspected the HTML and replaced all images in the rendered web page with the dropped in image.

The next example showed how JavaScript can leverage and manipulate ActionScript. JavaScript developers should consult the Flex 3 SDK documentation to know what is available and what packages the classes are in.

The application's back story is about wanting to display the user's version of an icon for a specific file extension. Showing a sample from the core in the Aptana (source available) that knows how to determine and show the custom icons. OS returns an Array of different icons. The example uses PNGEncoder in ActionScript to render the information. HTML can include ActionScript libraries by specifying the SWF as the script source.

<script src="library.swf"></script>

The last example was showing that HTML rendered in AIR can be manipulated by Flash. It loaded a simple HTML page and then applied Flash filters to various divs. Really cool capability. No source shown.

Tags: air flex html javascript onair2007boston