JSON and AS3 URLRequest Class

A while ago, the as3corelib has been published on Google Code with a useful tool: JSON encoder and decoder.

JSON (JavaScript Object Notation) is a lightweight computer data interchange format (that is intended to solve XML structure weight), that allows you to send Object (Array, Strings, Number, …) to your server scripts or to JavaScript.

[adsenseyu1]

JSON is commonly used by Yahoo Web Services for example.

To use JSON and URLRequest even faster and simpler, I’ve create a small class that allows you to configure your URLRequest in one line (called PhpInteract), to add variables and to precise if your variables are encoded in JSON.

[adsenseyu1]

AS3 example to load a XHTML file:

var mi:PhpInteract = new PhpInteract(); //New object of the PhpInteract Class
mi.loadFile("http://www.w3.org/TR/2008/WD-xhtml-access-20080107/");

Now to get the content of the file just do as usual with the onComplete Listener:

mi.addEventListener(Event.COMPLETE, completeHandler);

public function completeHandler(e:Event):void
	{
		//file is completely loaded
		trace("File Content :n"+mi.content);
	}

You are certainly thinking that a new Class to do this is completely useless… And I agree. Now we can do something more interesting and pass variables (encoded in JSON) to our server side script:

var arr:Array = new Array("a", "b", "c");//An array for the demo...
mi.loadFile("http://yourserver/fromFlash.php",arr, true);
mi.isJSON = true; //We specify that the content must be JSON encoded

Now for the demo, our below PHP code will decode the received JSON string and will re-encode it in JSON and echo it. Our Flash / Flex / AIR application will be able to decode the content as well and handle complex data from PHP (or any server side languages that can encode and decode JSON).

< ?php
$flash = $_POST['fromFlash'];

$testArray = json_decode($flash);

//We can access to the Array Element
echo "Array [0]".$testArray[0]."n";
echo "Array [1]".$testArray[1]."n";
echo "Array [2]".$testArray[2]."n";

echo json_encode($testArray);
?>

What you need to make it work:
– The as3corelib
– The PhpInteract Class

[adsenseyu1]

Below is a complete sample:

package
{
	import flash.display.Sprite;
	import ch.metah.mURL.PhpInteract;
	import flash.events.*;

	public class InitmURL extends Sprite
	{
		var mi:PhpInteract = new PhpInteract();
		public function InitmURL()
		{
			//var arr:Array = new Array("a", "b", "c");//for the demo
			//mi.loadFile("http://metah.ch/seo/fromFlash.php",arr, true);
			//mi.isJSON = true; //is JSON content in loaded file?

			mi.loadFile("http://www.w3.org/TR/2008/WD-xhtml-access-20080107/");

			//USE EventListener
			mi.addEventListener(Event.COMPLETE, completeHandler);
			mi.addEventListener(Event.OPEN, openHandler);
			mi.addEventListener(ProgressEvent.PROGRESS, progressHandler);
			mi.addEventListener(HTTPStatusEvent.HTTP_STATUS, HTTPHandler);
			mi.addEventListener(SecurityErrorEvent.SECURITY_ERROR, errorHandler);
		}

		public function completeHandler(e:Event):void
		{
			//file is completely loaded
			trace("File Content :n"+mi.content);
		}
		public function openHandler(e:Event):void
		{
			//trace("Download started");
		}
		public function progressHandler(e:ProgressEvent):void
		{
			//Handle Progress
			//trace("Loaded"+mi.bytesLoaded+"Total"+mi.totalBytes);
		}
		public function HTTPHandler(e:HTTPStatusEvent):void
		{
			//trace("HTTP Status:"+mi.httpStatus);
		}
		public function errorHandler(e:SecurityErrorEvent):void
		{
			//Handle Security Error Here
		}

	}
}

Ahmet