Specifications

17ADOBE FLEX 3
Building and Deploying Adobe Flex 3 Applications
Development directory structure
As part of the process of setting up the directory structure of your development environment, you define the
directory location for application-specific assets, assets shared across applications, and the location of other appli-
cation files and assets.
Flex file types
A Flex application consists of many different file types. Consider the following options when you decide where to
place each type of file.
The following table describes the different Flex file types:
Flex SDK directory structure
A typical Flex application consists of a main MXML file (the file that contains the <mx:Application> tag), one
or more MXML files that implement custom MXML components, one or more ActionScript files that contains
custom components and custom logic, and asset files.
File format Extension Description
MXML .mxml Your application typically has one main application MXML file that contains the
<mx:Application> tag, and one or more MXML files that implement your custom
MXML components.
ActionScript .as A utility class, Flex custom component class, or other logic implemented as an Action-
Script file.
SWC .swc A custom library file, or a custom component implemented as an MXML or ActionScript
file, then packaged as a SWC file.
A SWC file contains components that you package and reuse among multiple applica-
tions. The SWC file is then statically linked into your application at compile time when
you create the application’s SWF file.
RSL .swc A custom library implemented as an MXML or ActionScript file, and then deployed as a
Runtime Shared Library (RSL). An RSL is a stand-alone SWC file that is downloaded
separately from your application’s SWF file, cached on the client computer for use with
multiple application SWF files, and dynamically linked to your application.
CSS file .css A text file template for creating a Cascading Style Sheets file.
Assets .flv, .mp3, .jpg, .gif, .swf, .png,
.svg, .xml, other
The assets required by your application, including image, skin, sound, and video files.