Macromedia flex 2 Manual

34

Using ActionScript to Create Components

About scope

Scoping is mostly a description of what the 

this

 keyword refers to at any given point in your 

application. In the main MXML application file, the file that contains the 

<mx:Application>

 tag, the current scope is the Application object and, therefore, the 

this

 

keyword refers to the Application object. 

In an ActionScript component, the scope is the component itself and not the application or 
other file that references the component. As a result, the 

this

 keyword inside the component 

refers to the component instance and not the Flex Application object.

Nonvisual ActionScript components do not have access to their parent application with the 

parentDocument

 property. However, you can access the top-level Application object by using 

the 

mx.core.Application.application

 property.

For more information on scope, see Chapter 4, “Using ActionScript,” in Flex 2 Developer’s 
Guide.