User Guide

ApplicationDomain class 437
}
}
}
Other things to keep in mind when you work with application domains include the
following:
■ All code in a SWF file is defined to exist in an application domain. The current domain is
where your main application runs. The system domain contains all application domains,
including the current domain, which means that it contains all Flash Player classes.
■ All application domains, except the system domain, have an associated parent domain.
The parent domain for your main application's application domain is the system domain.
Loaded classes are defined only when their parent doesn't already define them. You cannot
override a loaded class definition with a newer definition.
The following diagram shows an application that loads content from various SWF files within
a single domain, domain1.com. Depending on the content you load, different application
domains can be used. The text that follows describes the logic used to set the appropriate
application domain for each SWF file in the application.
Loader
Loader
Loader
Application
Loader
Stage
Module
Module
Application domain 1
Security domain: domain1.com
module1.swf
module3.swf
Application domain 3
Module
application2.swf
application1.swf
Application domain 2
mx.core.Application
mx.core.Application
Usage A
Usage B
Usage C