MACROMEDIA FLEX-FLEX ACTIONSCRIPT LANGUAGE Service manual

Flex ActionScript Language Reference

Trademarks

ActiveEdit, ActiveTest, Add Life to the Web, Afterburner, Aftershock, Andromedia, Allaire, Animation PowerPack, Aria, Attain,

Authorware, Authorware Star, Backstage, Blue Sky Software, Blue Sky, Breeze, Bright Tiger, Clustercats, ColdFusion, Contents

Tab Composer, Contribute, Design In Motion, Director, Dream Templates, Dreamweaver, Drumbeat 2000, EDJE, EJIPT,

Extreme 3D, Fireworks, Flash, FlashHelp, Flash Lite, FlashPaper, Flex, Flex Builder, Fontographer, FreeHand, Generator, Help

To Source, HomeSite, Hotspot Studio, HTML Help Studio, JFusion, JRun, Kawa, Know Your Site, Knowledge Objects,

Knowledge Stream, Knowledge Track, LikeMinds, Lingo, Live Effects, MacRecorder Logo and Design, Macromedia,

Macromedia Action!, Macromedia Central, Macromedia Flash, Macromedia M Logo and Design, Macromedia Spectra,

Macromedia xRes Logo and Design, MacroModel, Made with Macromedia, Made with Macromedia Logo and Design, MAGIC

Logo and Design, Mediamaker, Movie Critic, Open Sesame!, RoboDemo, RoboEngine JFusion, RoboHelp, RoboHelp Office,

RoboInfo, RoboInsight, RoboPDF, 1-Step RoboPDF, RoboFlash, RoboLinker, RoboScreenCapture, ReSize, Roundtrip,

Roundtrip HTML, Shockwave, Sitespring, Smart Publishing Wizard, Software Video Camera, SoundEdit, Titlemaker,

UltraDev, Web Design 101, what the web can be, WinHelp, WinHelp 2000, WinHelp BugHunter, WinHelp Find+, WinHelp

Graphics Locator, WinHelp Hyperviewer, WinHelp Inspector, and Xtra are either registered trademarks or trademarks of

Macromedia, Inc. and may be registered in the United States or in other jurisdictions including internationally. Other product

names, logos, designs, titles, words, or phrases mentioned within this publication may be trademarks, service marks, or trade

names of Macromedia, Inc. or other entities and may be registered in certain jurisdictions including internationally.

Third-Party Information

This guide contains links to third-party websites that are not under the control of Macromedia, and Macromedia is not

responsible for the content on any linked site. If you access a third-party website mentioned in this guide, then you do so at your

own risk. Macromedia provides these links only as a convenience, and the inclusion of the link does not imply that Macromedia

endorses or accepts any responsibility for the content on those third-party sites.

translated, or converted to any electronic or machine-readable form in whole or in part without prior written approval of

Macromedia, Inc. Part Number ZFE15M200

Acknowledgments

Project Management: Barbara Herbert, Stephen Gilson

Writing: Jody Bleyle, Mary Burger, Kim Diezel, Stephen Gilson, Stephanie Gowin, Dan Harris, Barbara Herbert, Matt Horn,

Barbara Nelson, Shirley Ong, Michael Peterson, Tim Statler

Managing Editor: Rosana Francescato

Editing: Linda Adler, Mary Ferguson, Mary Kraemer, Noreen Maher, Antonio Padial, Lisa Stanziano, Anne Szabla

Production Management: Patrice O’Neill

Media Design and Production: Adam Barnett, Christopher Basmajian, Aaron Begley, John Francis

Second Edition: November 2004

Macromedia, Inc.

600 Townsend St.

San Francisco, CA 94103

CONTENTS

INTRODUCTION: Getting Started with ActionScript . . . . . . . . . . . . . . . . . . . . . . . 5

Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Using the documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Typographical conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Terms used in this document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Additional resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

PART I: Welcome to ActionScript

CHAPTER 1: ActionScript Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Differences between ActionScript and JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . 10

Unicode support for ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

About data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Assigning data types to elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

About variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Using operators to manipulate values in expressions . . . . . . . . . . . . . . . . . . . . . . . 31

Using condition statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Using built-in functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Creating functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

CHAPTER 2: Creating Custom Classes with ActionScript 2.0 . . . . . . . . . . . . . . . 45

Principles of object-oriented programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Using classes: a simple example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Creating and using classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Creating dynamic classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Using packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Creating and using interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Instance and class members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Implicit getter/setter methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Understanding the classpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Importing classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

4 Contents

CHAPTER 3: Working with External Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Sending and loading variables to and from a remote source . . . . . . . . . . . . . . . . . . 67

Sending messages to and from Flash Player . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

PART II: Reference

CHAPTER 4: About the ActionScript Language Reference . . . . . . . . . . . . . . . . . 77

Sample entry for most ActionScript elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Sample entry for classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

CHAPTER 5: ActionScript Core Language Elements. . . . . . . . . . . . . . . . . . . . . . 80

CHAPTER 6: ActionScript Core Classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

CHAPTER 7: ActionScript for Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490

APPENDIX A: Deprecated Flash 4 operators . . . . . . . . . . . . . . . . . . . . . . . . . . . 809

APPENDIX B: Keyboard Keys and Key Code Values . . . . . . . . . . . . . . . . . . . . . 811

Letters A to Z and standard numbers 0 to 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 811

Keys on the numeric keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813

Function keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813

Other keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 814

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 817

INDEX OF LANGUAGE ELEMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823

INTRODUCTION

Getting Started with ActionScript

Macromedia Flex developers can use ActionScript to extend the functionality of their Flex

applications. ActionScript is an ECMAScript-based language that provides support for object-

oriented development. You are not required to use ActionScript to use Flex, but it provides flow

control and object manipulation features that are not available in strict MXML.

Intended audience

This manual assumes that you already installed Macromedia Flex and know how to use it. If you

have written programs before, ActionScript will seem familiar. But if you’re new to programming,

ActionScript isn’t hard to learn. It’s easy to start with simple commands and build more

complexity as you progress.

Using the documentation

This manual provides an overview of ActionScript syntax, information on how to use

ActionScript when working with different types of objects, and details on the syntax and usage of

every language element. The following list summarizes the contents of this manual.

•Chapter 1, “ActionScript Basics,” on page 9 describes the terminology and basic concepts used

in the rest of the manual.

•Chapter 2, “Creating Custom Classes with ActionScript 2.0,” on page 45 describes how to

create custom classes and objects for manipulating data in your applications.

•Chapter 3, “Working with External Data,” on page 67 describes how to process data from

external sources using server- or client-side scripts in your applications.

•Chapter 4, “About the ActionScript Language Reference,” on page 77 provides an overview of

the second part of the manual, which describes the elements that comprise the ActionScript

language.

•Chapter 5, “ActionScript Core Language Elements,” on page 80 explains all of the elements of

the ActionScript language that are not related to a particular class or to a particular

Macromedia product.

•Chapter 6, “ActionScript Core Classes,” on page 232 documents all of the classes of the

ActionScript language that are not related to a particular Macromedia product.

6 Introduction: Getting Started with ActionScript

•Chapter 7, “ActionScript for Flash,” on page 490 describe functions, properties, and classes of

Macromedia Flash Player that you can use in a Macromedia Flex application, if appropriate.

•Appendix A, “Deprecated Flash 4 operators,” on page 809 lists all the ActionScript operators

and their associativity.

•Appendix B, “Keyboard Keys and Key Code Values,” on page 811 lists all the keys on a

standard keyboard and the corresponding ASCII key code values that are used to identify the

keys in ActionScript.

Typographical conventions

The following typographical conventions are used in this manual:

•Code font indicates ActionScript code.

•Code font italic indicates an element, such as an ActionScript parameter or object name,

that you replace with your own text when writing a script.

Terms used in this document

The following terms are used in this manual:

•You refers to the developer who is writing a script or application.

•The user refers to the person who is running your scripts and applications.

•Compile time is the time at which you publish, export, test, or debug your document.

•Runtime is the time at which your script is running in Flash Player.

ActionScript terms such as method and object are defined in Chapter 1, “ActionScript Basics,” on

page 9.

Additional resources

Specific documentation about Macromedia Flash and related products is available separately.

•For information about creating communication applications with Flash Communication

Server, see Developing Communications Applications and Managing Flash Communication Server.

•For information about building Flex applications, see Developing Flex Applications.

The Macromedia DevNet website (www.macromedia.com/devnet) is updated regularly with the

latest information on Flash, plus advice from expert users, advanced topics, examples, tips, and

other updates. Check the website often for the latest news on Flash and how to get the most out

of the program.

The Macromedia Flash Support Center (www.macromedia.com/support/flash) provides

TechNotes, documentation updates, and links to additional resources in the Flash community.

PART I

Welcome to ActionScript

This part includes information on using the ActionScript language. For information on the

classes and language elements you can use in your scripts, see Part II, “Reference.”

Chapter 1: ActionScript Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chapter 2: Creating Custom Classes with ActionScript 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Chapter 3: Working with External Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

PART I

CHAPTER 1

ActionScript Basics

ActionScript has rules of grammar and punctuation that determine which characters and words

are used to create meaning and in which order they can be written. For example, in English, a

period ends a sentence; in ActionScript, a semicolon ends a statement.

The general rules described in this section apply to all ActionScript. Most ActionScript terms also

have individual requirements; for the rules for a specific term, see its entry in Part II, “Reference.”

Applying the basics of ActionScript in a way that creates elegant programs can be a challenge for

users who are new to ActionScript.

This section contains the following topics:

•“Differences between ActionScript and JavaScript” on page 10

•“Terminology” on page 11

•“Syntax” on page 13

•“About data types” on page 18

•“Assigning data types to elements” on page 23

•“About variables” on page 27

•“Using operators to manipulate values in expressions” on page 31

•“Using condition statements” on page 39

•“Using built-in functions” on page 41

•“Creating functions” on page 41

10 Chapter 1: ActionScript Basics

Differences between ActionScript and JavaScript

ActionScript is similar to the core JavaScript programming language. You don’t need to know

JavaScript to use and learn ActionScript; however, if you know JavaScript, ActionScript will

seem familiar.

This manual does not attempt to teach general programming. There are many resources that

provide more information about general programming concepts and the JavaScript language.

•The European Computers Manufacturers Association (ECMA) document ECMA-262 is

derived from JavaScript and serves as the international standard for the JavaScript language.

ActionScript is based on the ECMA-262 specification. For more information, see www.ecma-

international.org/publications/standards/Ecma-262.htm.

•Netscape DevEdge Online has a JavaScript Developer Central site (http://

developer.netscape.com/tech/javascript/index.html) that contains documentation and articles

useful for understanding ActionScript. The most valuable resource is the Core JavaScript Guide.

•The Java Technology site has tutorials on object-oriented programming (http://java.sun.com/

docs/books/tutorial/java/index.html) that are targeted for the Java language but are useful for

understanding concepts that you can apply to ActionScript.

Some of the differences between ActionScript and JavaScript are described in the following list:

•ActionScript does not support browser-specific objects such as Document, Window,

and Anchor.

•ActionScript does not completely support all the JavaScript built-in objects.

•ActionScript does not support some JavaScript syntax constructs, such as statement labels.

•In ActionScript, the eval() function can perform only variable references.

•ActionScript2.0 supports several features that are not in the ECMA-262 specification, such as

classes and strong typing. Many of these features are modeled after the ECMAScript 4 Draft

Proposal currently in development by ECMA TC39-TG1 (see www.mozilla.org/js/language/

es4/index.html), the standards committee in charge of the evolution of the ECMA-262

specification.

•ActionScript does not support regular expressions using the RegExp object. However,

Macromedia Central does support the RegExp object.

Unicode support for ActionScript

Macromedia Flex supports Unicode text encoding for ActionScript. This means that you can

include text in different languages in an ActionScript file. For example, you can include text in

English, Japanese, and French in the same file. For more information on Unicode support in Flex,

see “Using MXML” in Developing Flex Applications.

This manual suits for next models

Table of contents

Other MACROMEDIA Software manuals

MACROMEDIA

MACROMEDIA COLFUSION MX 7-CFML User manual

MACROMEDIA

MACROMEDIA BREEZE-FOR MEETING PRESENTERS User manual

MACROMEDIA

MACROMEDIA FLASH COMMUNICATION SERVER MX-SERVER-SIDE COMMUNICATION ACTIONSCRIPT... User manual

MACROMEDIA

MACROMEDIA DREAMWEAVER 8-GETTING STARTED WITH... User manual

MACROMEDIA

MACROMEDIA FLASH MX 2004-DATA Operation instructions

MACROMEDIA

MACROMEDIA COLDFUSION 5-DEVELOPING User manual

MACROMEDIA

MACROMEDIA DREAMWEAVER MX 2004-EXTENDING DREAMWEAVER User manual

MACROMEDIA

MACROMEDIA COLDFUSION 4.5- TO CFML User manual

MACROMEDIA

MACROMEDIA BREEZE-USING THE BREEZE PLUG-IN FOR MICROSOFT... Mounting instructions

MACROMEDIA

MACROMEDIA BREEZE User manual

MACROMEDIA

MACROMEDIA FLEX-GETTING STARTED WITH FLEX User manual

MACROMEDIA

MACROMEDIA DIRECTOR MX 2004-USING DIRECTOR Mounting instructions

MACROMEDIA

MACROMEDIA FLASH MEDIA SERVER 2-INSTALLING FLASH MEDIA SERVER... User manual

MACROMEDIA

MACROMEDIA FIREWORKS 2-USING FIREWORKS Mounting instructions

MACROMEDIA

MACROMEDIA COLDFUSION 4.5-ADMINISTRING COLDFUSION... User manual

MACROMEDIA

MACROMEDIA DREAMWEAVER 8 User manual

MACROMEDIA

MACROMEDIA FLASH 8-FLASH Service manual

MACROMEDIA

MACROMEDIA FLASH 8-USING FLASH VIDEO ENCODER Mounting instructions

MACROMEDIA

MACROMEDIA STUDIO 8-EXPLORING STUDIO 8 User manual

MACROMEDIA

MACROMEDIA COLDFUSION 4.5-DEVELOPING WEB User manual

MACROMEDIA

MACROMEDIA COLFUSION MX 7 - INSTALLING AND USING COLDFUSION... Guide

MACROMEDIA

MACROMEDIA CONTRIBUTE 3 - USING AND ADMINISTERING... Mounting instructions

MACROMEDIA

MACROMEDIA DIRECTOR MX 2004-USING DIRECTOR Mounting instructions

MACROMEDIA

MACROMEDIA BREEZE-USING THE BREEZE PUBLISH WIZARD Mounting instructions

Popular Software manuals by other brands

COMPRO

COMPRO COMPROFM manual

Muratec

Muratec OFFICEBRIDGE ONLINE user guide

Oracle

Oracle Contact Center Anywhere 8.1 installation guide

Adobe

Adobe 65007312 - Photoshop Lightroom Programmer's guide

Avaya

Avaya NULL One-X for RIM Blackberry user guide

HP ProLiant BL420c user guide

PS Audio

PS Audio PowerPlay Programming manual

Brady

Brady LOCKOUT PRO 3.0 Administrator's guide

Avaya

Avaya Interaction Center user guide

Texas Instruments

Texas Instruments TI-83 Plus Silver Edition Guide book

Novell

Novell GROUPWISE 8 - INTERNET AGENT manual

Oracle

Oracle Application 9i Configuration guide

Acer

Acer RDM user guide

Canon

Canon Vixia HF21 instruction manual

Canon

Canon ZR950 instruction manual

Samsung

Samsung Auto Backup user manual

Polycom

Polycom Vortex EF2201 Application note

Brocade Communications Systems

Brocade Communications Systems Brocade 8/12c user manual