AS3 ExternalInterface.call, why it doesn't work on Chrome or IE?

Question

import flash.external.ExternalInterface;
var pageURL:String = ExternalInterface.call('window.location.href.toString');

The above code seems to work on Firefox, but when I try it with Chrome or IE it doesn't work (it causes an Error and stops the swf's execution).

Any hint?

Answer 1

ExternalInterface works in recent versions of all major browsers. The first thing you should do is wrap that call in a check to see if it is currently available:

if(ExternalInterface.available)
{
  ExternalInterface.call('window.location.href.toString');
}

The problem with Chrome and IE may be the call to window.location.href. Your best bet is to put this into a JS function, and then call that function from AS, like so:

//JS:

function reportHref(){
    return window.location.href.toString(); 
    // I'm not sure this is good cross-browser JS. 
    // If it isn't, you can at least test it directly in the browser
    // and get a javascript error that you can work on.
}

//AS:
var result:String = "";
if(ExternalInterface.available)
{
    result = ExternalInterface.call("reportHref");
}
else
{
    result = "External Interface unavailable";
}
trace(result);

Also, make sure the function you are trying to call is already present in the DOM before you try to call it - if you add your SWF before you add the script, and make the call to ExternalInterface immediately, then it will fail because reportHref doesn't exist yet.

And, finally, it's possible that a call from within the SWF to the window.location object might fail due to sandboxing, which won't be the case if you make the call from a JS funciton in the page.

The docs on ExternalInterface are pretty comprehensive, with good examples:

http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/external/ExternalInterface.html