Parameter URL must be non-null

Question

I get an error Parameter url must be non-nullwhen trying to transfer the path of the XML file to the Shockwave Flash object.

The javascript code is as follows

<script type="text/javascript">
    var so = new SWFObject("preview.swf", "", "100%", "100%", "9", "#ffffff");
    so.addParam("allowFullScreen", "true");
    so.addParam("scale", "noscale");
    so.addParam("menu", "false");
    so.addVariable("xmlPath", "xml/exampleData.xml");
    so.write("flashcontent");
</script>

As you can see the XML file I'm trying to load in the SWF file, this is exampleData.xml

In ActionScript, I declared the xmlPath variable as follows:

 public var xmlPath:String

and in the boot event I made the appropriate changes.

private function loadComp(data:String):void
        {
            xmlModel.xml = new XML(data);
            new LoadXml(xmlPath, picHandler);
        }

And here is the question.

What am I doing wrong here? Why am I getting an error Parameter url must be non-null?

PS If I hardcode the path, everything works fine in the actionscript file!

private function loadComp(data:String):void
        {
            xmlModel.xml = new XML(data);
            new LoadXml('xml/exampleData', picHandler);
        }

Answer 1

I usually do such things with the flashvar parameter in the embed code.

   so.addParam('flashvars','xmlPath=xml/exampleData.xml');

ActionScript...

   private var xmlPath:string;
   xmlPath = root.loaderInfo.parameters.xmlPath;