A program is a set of written instructions to be executed (i.e., carried out) by a computer or a software application. The written, human-readable text of a program is called source code, or just code. The person who creates a program is called a programmer, a coder, or a developer. Every program is written in a particular programming language, just as every book is written in a particular language (English, Russian, Japanese, etc.). Programming languages dictate the syntax and grammar that programmers must use to form the instructions in a given program. This book provides from-the-ground-up coverage of the syntax, grammar, and usage of one specific programming language, ActionScript 3.0. Get ready for a good time.
ActionScript code is written in plain text, so an ActionScript program can be created with nothing more than a simple text editor, such as Notepad on Windows or TextEdit on Macintosh. However, most ActionScript programmers write ActionScript code using one (or both) of two commercial tools produced by Adobe Systems Incorporated: Flex Builder and the Flash authoring tool.
Flex Builder is an integrated development environment, or IDE. An IDE is an application for writing and managing code, much as a word processor is an application for creating printed documents. Developers use Flex Builder to create software applications and multimedia content using either ActionScript or MXML, or both. MXML is an XML-based language for describing user interfaces.
By contrast, the Flash authoring tool is a hybrid design, animation, and programming editor. Developers use the Flash authoring tool to create software applications and multimedia content by combining ActionScript code with manually drawn graphics, animation, and multimedia assets.
ActionScript 3.0 is supported by Flex Builder 2 or higher, and Flash CS3 (Version 9 of the Flash authoring tool) or higher. To obtain a copy of Flex Builder, visit http://www.adobe.com/products/flex/productinfo/overview/. To obtain a copy of the Flash authoring tool, visit http://www.adobe.com/go/flash/.
The vast majority of this book concentrates on the creation of software applications and multimedia content using pure ActionScript (i.e., code only). Chapter 29 covers the use of ActionScript in the Flash authoring tool. This book specifically does not include coverage of MXML. For coverage of MXML, see O'Reilly's Programming Flex 2 (Kazoun and Lott, 2007) and Adobe's Flex Builder documentation.