Actionscript Cookbook

18.1. Loading Variables from a Text File

Problem

You want to load variables into your Flash movie from an external text file.

Solution

Use the LoadVars.load( ) method.

Discussion

You should use the LoadVars.load( ) method when you want to load URL-encoded data into your Flash movie from a text file. This technique allows your Flash movie to access values that change frequently without modifying the Flash movie itself.

The load( ) method requires a URL where it can find the text file. The URL can be an absolute or relative address.

// You must first create the LoadVars object.
myLoadVars = new LoadVars(  );

// This example loads values from a text file at an absolute URL.
myLoadVars.load("http://www.person13.com/myText.txt");

// This example loads values from a text file located at a relative URL, in this
// case, in the same directory as the Flash .swf file.
myLoadVars.load("myText.txt");

Here is an example of what the text file might contain:

someText=testing&myVariable=123

Once you invoke the load( ) method of a LoadVars object, Flash attempts to load the values from that URL into the same LoadVars object. After the data loads, Flash attempts to decode the values and invokes the object’s onLoad( ) method. It is up to you to define the onLoad( ) method so that the object can do something useful once the data is loaded and decoded.

You should define an onLoad( ) method that expects a Boolean parameter indicating whether Flash was able to load the values. If Flash cannot load the values, ...