Daniel Eneström » Tutorial http://blog.enestrom.com Ramblings of a web developer Wed, 27 Jan 2010 19:49:14 +0000 http://wordpress.org/?v=2.8.4 en hourly 1 AMFPHP and Flex http://blog.enestrom.com/20080808/amfphp-and-flex/ http://blog.enestrom.com/20080808/amfphp-and-flex/#comments Fri, 08 Aug 2008 13:44:45 +0000 Daniel Eneström http://blog.enestrom.com/?p=13 Being a LAMP (Linux Apache MySQL PHP) guy as well as a Flex developer it didn’t take me long to discover AMFPHP. If you haven’t heard of it I can tell you in short it’s a framework for sending and receiving data between Actionscript and PHP, without having to use an XML layer or similar in between, so to speak. It’s really neat, because lets say you extract an array of rows from your MySQL database, then you can just pass the entire array back to Actionscript and it will be received as an Actionscript array in the other end.

Would you like to try it? This is how to do it:

1. Download the latest AMFPHP package from www.amfphp.org

2. Unpack and (preferably) place the folder called amfphp in the document root on your web server.

3. By default the AMFPHP gateway is set to converting all UTF-8 data to Latin 1. Big NO NO for “international” developers like me, so you should open the gateway.php file in the amfphp folder for editing and change the following line (it should be around line 127):

  1. $gateway->setCharsetHandler("utf8_decode", "ISO-8859-1", "ISO-8859-1");

to

  1. $gateway->setCharsetHandler("iconv","UTF-8","UTF-8");

If you don’t do this all UTF-8 special characters from the database will be distorted on arriving at the Flex application.

4. Now create a simple PHP class file, call it HelloWorld.php, and place it in the /amfphp/services folder. You should use a commenting pattern like that of PHPDoc. Here is a simple HelloWorld example:

/**
  1.  * A simple amfphp service.
  2.  */
  3. class HelloWorld
  4. {
  5.  /**
  6.   * A simple HelloWorld function
  7.   * @returns A string containing the phrase 'Hello World!'
  8.   */
  9.  function SayHello()
  10.  {
  11.   return "Hello World!";
  12.  }
  13.  
  14.  /**
  15.   * A simple HelloWorld function that bounces back the given string
  16.   * @returns A string containing the supplied string
  17.   */
  18.  function SayWhat($string)
  19.  {
  20.   return $string;
  21.  }
  22. }

In this class I’ve put two functions; one that returns the string ‘Hello World!’ and another that returns whatever string you send to it. Okay, so let’s get on with the show…

5. Now you can test your service by browsing to the browser folder. It should have a URL similar to this: yourserver.com/amfphp/browser. In the service browser you can test whether your class is working as it should.

6. Flex
To simplify things I’ve created a small class for the implementation of this in Flex. There is a number of ways of doing this, but I’ve chosen the one way that I am most comfortable with.

For ease of use, create an actionscript document in your Flex Projects root directory called AMFPHP.as and past the following code into the file:

package {
  1.  import flash.net.NetConnection;
  2.  import flash.net.Responder;
  3.  
  4.  public class AMFPHP
  5.  {
  6.   private static var gateway:String = "http://www.yourserver.com/amfphp/gateway.php";
  7.   private static var connection:NetConnection = new NetConnection;
  8.   connection.connect(gateway);
  9.  
  10.   public function AMFPHP() : void
  11.   {
  12.    // Static class
  13.   }
  14.  
  15.   public static function send(serviceFunction:String, resultHandler:Function, faultHandler:Function, … args:*) : void
  16.   {
  17.    trace("AMFPHP("+serviceFunction+")");
  18.    // Create responder
  19.    var responder:Responder = new Responder(resultHandler, faultHandler);
  20.    // Create an array that will temporarily store all the arguments
  21.    var collectArgs:Array = new Array;
  22.    // Add the fixed arguments
  23.    collectArgs.push(serviceFunction);
  24.    collectArgs.push(responder);
  25.    // Loop through the optional arguments and add them too
  26.    for (var i:uint=0; i<args.length; i++)
  27.    {
  28.     collectArgs.push(args[i]);
  29.    }
  30.    // Create a reference to the function we will call
  31.    var callFunction:Function = connection.call;
  32.    // Call the function using the arguments
  33.    callFunction.apply(connection,collectArgs);
  34.   }
  35.  }
  36. }

The only thing you have to change here is the URL to the gateway.php file on your server at line 7 in the file.

7. Usage

To use this in your code you will need three things:

• Calling the service using the static AMFPHP.send() function
• A function that handles the result coming from amfphp
• A function that handles errors

This is the first HelloWorld example (without the argument). The first argument for the send() function is a string describing the path to the function, with this structure: [directory.]class.function, within the services folder. A directory is not necessary, but can be convenient if you have packages of many classes.

private function helloWorld() : void
  1. {
  2.  AMFPHP.send("HelloWorld.SayHello",onResult,onFault);
  3. }
  4.  
  5. private function onResult(result:String) : void
  6. {
  7.  trace(result);
  8. }
  9.  
  10. private function onFault(result:Object) : void
  11. {
  12.  trace(String(result.description));
  13. }

Easy huh!?

And the example with the argument is pretty much the same, but with an argument added to the end of the function call. Like this:

private function helloWorld() : void
  1. {
  2.  AMFPHP.send("HelloWorld.SayWhat", onResult, onFault, "Hello to you!");
  3. }
  4.  
  5. private function onResult(result:String) : void
  6. {
  7.  trace(result);
  8. }
  9.  
  10. private function onFault(result:Object) : void
  11. {
  12.  trace(String(result.description));
  13. }

Note that I changed the path to the function from HelloWorld.SayHello to HelloWorld.SayWhat to use the other function in the class.

Well, that’s it. Hope it was of some use. Good luck!

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