Using FABridge and swfobject together

June 5th, 2008 by Ryan

Although there’s no visible Flash on Photosleeve, we use some of the Flash image processing capabilities when you upload photos through the site.

There are all sorts of different ways to include Flash, but after some research and poking around, we decided to go with swfobject.

All was swell at first, as we were using ExternalInterface to call between Flash and JavaScript. But that got pretty burdensome once we got past the proof-of-concept phase. Thankfully, we found the Adobe Flash AJAX Bridge (hereafter FABridge), which automatically handles exposing things, marshalling params, etc. It’s really great, actually.

So we had everything working great in IE, but Firefox was a no go. After debugging through things for a while (thanks, Firebug!) I realized that FABridge requires you to use the ‘embed tag within an object tag’ method (is that the one called Flash Satay?). Since I was using swfobject, no dice.

I found that the fix was just to comment out the bit of code in FABridge.js that looked for the Embed tag for certain user agents (see diff at the bottom of this post).

Incidentally, I also discovered that if you have more than one object tag on the page, you must include the bridgeName flashvar for FABridge to figure things out. The syntax for swfobject looks like this:

// swfobject_fabridge_example.js (Sample Code)
swfobject.embedSWF(
    mySwfFile,
    mySwfAlternateContent,
    myWidth,
    myHeight,
    myMinFlashVersion,
    myExpressInstallUri,
    { bridgeName: 'myBridgeName' },
    { allowScriptAccess: 'always' }
);
// and later ...
var flash = FABridge.myBridgeName.root();

You have to get rid of lines 113 and 148-169, below is a diff. FABridge.js has the MIT License blazened at the top, so have no fear when deleting huge portions of it.

--- a/fabridge/src/bridge/FABridge.js 2008-02-11 06:44:57.000000000 -0800
+++ b/fabridge/src/bridge/FABridge.js 2008-05-13 18:17:25.000000000 -0700
@@ -110,7 +110,7 @@
 {
     var searchStr = "bridgeName="+ bridgeName;

-    if (/Explorer/.test(navigator.appName) || /Konqueror|Safari|KHTML/.test(navigator.appVersion))
     {
         var flashInstances = document.getElementsByTagName("object");
         if (flashInstances.length == 1)
@@ -145,28 +145,28 @@
             }
         }
     }
-    else
-    {
-        var flashInstances = document.getElementsByTagName("embed");
-        if (flashInstances.length == 1)
-        {
-            FABridge.attachBridge(flashInstances[0], bridgeName);
-        }
-        else
-        {
-            for(var i = 0; i < flashInstances.length; i++)
-            {
-                var inst = flashInstances[i];
-                var flashVars = inst.attributes.getNamedItem("flashVars").nodeValue;
-                if (flashVars.indexOf(searchStr) >= 0)
-                {
-                    FABridge.attachBridge(inst, bridgeName);
-                }
-
-            }
-        }
-    }
-    return true;
 }

 // used to track multiple bridge instances, since callbacks from AS are global across the page.