How to get URL query-string variables within Flex application

On flexcoders, someone asked, how to get the URL parameters in a Flex 2.0 application? By URL parameter, I mean the query-string variables, as shown below:

http://yourserver/yourapp.swf?name=Joe&age=22 or http://yourserver/yourapp.mxml?name=Joe&age=22

Note: To get the variables in flex via mxml file, you need server-side compilation of mxml files.

You can get the values of the params using from




object, which contains the name-value pairs (hash-map).

For example,



would return "Joe", considering above example URL. You can find more information about this in livedocs:

Then someone asked, what if your swf is embedded in custom html wrapper, how to get the query-string params inside swf?

Most of us use ExternalInterface class in Macromedia Flash Player 8(onwards) to invoke some JavaScript functions and extract the value in ActionScript.

I wrote a quick-and-dirty class in ActionScript 3, which would get the values of params from URL query-string for you. You don't need any extra JavaScript code in HTML. The same logic can be used for any an ActionScript 2.0 running Macromedia Flash Player 8.
QueryString class has following properties:-

  • parameters - an Object which contains the name-value pairs from query-string
  • queryString- String, this contains the entire query-string (url-encoded) name-value pairs.
  • url- String, this returns the complete URL of the wrapper page with query-string.

See demo
Download source files