ExternalInterface.call() not getting return value

Question

I have a Javascript function that returns the innerHTML of a div. I am attempting to call this function from Actionscript and store the return value. I know that the Javascript function is being called because there is an alert that displays the return data, The data that is returned to Actionscript, however, is null. I am not sure what is causing this. Here is a code example of what I am attempting to do:

Javascript:
function JSFunc () {
     var x = document.getElementById("myDiv");
     alert(x.innerHTML);
     return x.innerHTML;
}

Actionscript:
import flash.external.*;
if (ExternalInterface.available) {
     var retData:Object = ExternalInterface.call("JSFunc");
     if(retData != null) {
          textField.text = retData.toString();
     } else {
          textField.text = "Returned Null";
     }
} else {
     textField.text = "External Interface not available";
}

Like I said earlier, the alert shows up with the contents of the div but the text in the textfield is always "Returned Null", meaning that the ExternalInterface is available. I should add that I can only test this in IE7 and IE8. Any advice on what to do would be much appreciated.

Answer 1

You should use the import statement

import flash.external.*;

Answer 2

Try adding as String to the call:

textField.text = ExternalInterface.call("JSFunc") as String;

Answer 3

I also noticed you got a typo in your code => textField != textfield

Answer 4

Try to get the object back from your external interface call without casting it first, and take a look at it in the debugger. If it is not a string, trying to cast it to a string will result in null. This should be a string, but it doesn't hurt to see what you are actually getting back before you try to work with it.

Answer 5

This is a working sample based on the code you provided. You can right click it to view the source. I suspect the problem lies in the HTML for 'myDiv' or when you are making the actionscript call.

Answer 6

The source of the problem that I have been having has to do the object tag that I was using to embed the flash movie. I was using a tag that followed this example http://www.w3schools.com/flash/flash_inhtml.asp, I changed it to match this example: http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_4150 and then I made sure that I added id to the object and everything worked.

Answer 7

It seems to me that your problem is that from javascript you are returning a string, the innerHTML property of your myDiv element. In actionscript you have datatyped the variable that the ExternalInterface call returns to as an Object, but it is a String. Maybe you have already caught this, but I can't tell as you haven't amended your code.

//The following is an Object
var x = document.getElementById("myDiv");

/*
You are returning the innerHTML property of x, a string, but on the
flash end your expecting an object in your actionscript.
*/
return x.innerHTML;

//The following seems incorrect to me.
var retData:Object = ExternalInterface.call("JSFunc");

//Should be
var retData:String = ExternalInterface.call("JSFunc");

Hope this was helpful, take care.
Brian Hodge blog.hodgedev.com

Answer 8

Hi,

I'm facing a similar issue. And the following link doesn't seem to work. http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_4150

Can someone please let me know what the fix is?

Thanks, Sushma