External Interface Tip « ActionScript 3, Flash, Flex Reflections

Posted by: smackme | August 21, 2007

External Interface Tip

This article will treat solutions to “swfObject.callback() is not a function” problem when using ExternalInterface in Flash/Flex.

Ok, not so long ago I had to test some interaction between JavaScript and ActionScript. It wasn’t the first time I was using EI, and since it’s always good to start from a working examle, I set up the one provided by Adobe, test it – works fine.

(An important note – you have to run it from a web server and add it to flash player’s security domain. I’ll show you how later). Now in this example the flash function is called the onClick event of form button is fired:

<input type="button" value="Send" onclick="callAsFunction();" >

while what I needed was to call the AS function as soon as the document loads. I decided to put it in body’s onLoad event:

<body onload="callAsFunction();">

and SURPRIIIIIIIISSEEEEEEEE !!!! – not working!
I double check everything again and nothing. WHAT THE … ?! [picture of me scratching the head]. It is there, why isn’t it working?? The error message thrown by JavaScript was “blabla.blabla() is not a function”
I am a person who thinks that if smth isn’t working right in a computer program, it’s most certainly your fault, not computer’s, so I start thinking of a solution. I searched the net and all the examples/tutorials/forums out there were variations of the one provided by Adobe, which is calling AS function after the button is pushed. GREAT!
I made another test, called the function from within a <script> tag after the embed code – didn’t work either. So I thought, perhaps in both cases the flash object simply isn’t ready yet.
Another test – add a timeout:

setTimeout('callAsFunction();', 100)

TADAAA, it worked, BUT, only in 9 out of 10 page refreshes. If I set timeout to smth like 500 it solves the issue, but it’s not a good solution. Who wants to wait half a second? It can screw many things up. So what do we do? We make flash tell JavaScript when it’s loaded and ready, and only after that, call AS functions. Piece of cake!
Here is the JS code:

    function onFlashReady() {
		sendToAS("another test message");
    }

    function callJS(value) {
        onFlashReady();
        return "Hi Flash.";
    }

    function thisMovie(movieName) {
         if (navigator.appName.indexOf("Microsoft") != -1) {
             return window[movieName];
         } else {
             return document[movieName];
         }
     }
     function sendToAS(value) {
         thisMovie("test").callAS(value);
     }

and AS code:

import flash.external.*;

System.security.allowDomain("http://localhost");

tf.text = "Flash loaded and ready!";
tf.text += "nEI available: " + ExternalInterface.available;

var wasSuccessful:Boolean = ExternalInterface.addCallback("callAS", this, func);
tf.text += "nAdd callback success: " + wasSuccessful;

greeting = String(ExternalInterface.call("callJS", "Hello JS!"));
tf.text += "nI called Javascript and it said: " + greeting;

function func(value:String) {
	tf.text += "nJavascript called me, saying: " + value;
}

Note that you need a TextField on the stage with the name “tf”. Give the swf object the name “test” when embedding.
You can also download the source files here: http://www.box.net/shared/ocq972d435
IMPORTANT!!! – the html file needs to be run on a web server. Simply douleclicking it won’t work!!!
This should appear in the textfield:
“Flash loaded and ready!
EI available: true
Add callback success: true
Javascript called me, saying: another test message
I called Javascript and it said: Hi Flash.”

Have fun coding!

Posted in ActionScript, ActionScript 2, ActionScript 3, Flash CS3, Flex, Tutorials

Responses

hi,

i am trying to call a flex function called myflexFunction from JS. it works well when i call it once.

But when i need to to be called to set of movies then it is not working.

code:
for(var i=0; i<DC[j].childNodes.length; i++)
{
if (DC[j].childNodes[i].id.substr(0, 4) == “Item”)
{
var no=DC[j].childNodes[i].id.charAt(4);
var myid = “myMovie”+no; document.getElementById(myid).myFlexFunction(myid);
}

}
…

then flex function will in turn call a JS named test. this function is called only for one of the movies. But why all the movies are not calling the test function?
By: arthy on December 18, 2007
at 7:11 am

Reply
how to i call the flash function from vc++?
By: aravindakumar on December 19, 2007
at 5:39 am

Reply
I am not familiar with CPP and the IDE’s.
I am sorry, but I am not the one who can give you the answer
By: smackme on December 19, 2007
at 2:34 pm

Reply
1137: Incorrect number of arguments. Expected no more than 2.

I think there are one too many args here:
var wasSuccessful:Boolean = ExternalInterface.addCallback(“callAS”, this, func);
By: Jason on May 19, 2008
at 5:39 pm

Reply
Hi,

I call a function of vc++ activeX from “Test.html” file.I can play Flash files by clicking “play” button in html file.(The play fuction is defined in vc++ workspace.)

Now I have fullscreen button in “test.html”.
so my question is what will be my fuction defination for fullscreen in vc workspace.

Thnx in advance,
Nandan
By: Nandan on July 11, 2008
at 6:08 am

Reply
Nandan, I am sorry but I can’t help you with your issue
By: smackme on July 17, 2008
at 1:24 pm

Reply