Actionscript: the Definitive Guide

ActionScript: The Definitive Guide

Table of Contents

Last Updated: January 13, 2001

Foreword (by Gary Grossman)
Preface

Part I: ActionScript Fundamentals

1) A Gentle Introduction for Non-Programmers

Some Basic Phrases

Creating Code
Say Hi to Flash
Keeping Track of Things (a.k.a. Variables)
The Wizard Behind the Curtain (a.k.a. the Interpreter)
Extra Info Required (a.k.a. Arguments)
ActionScript Glue (a.k.a. Operators)
Putting It All Together

Further ActionScript Concepts

Flash programs
Script Data (a.k.a. Expressions)
Two Vital Statement Types: Conditionals and Loops
Modular Code (a.k.a. Functions)
Movie Clip Instances
The Event-Based Execution Model

Building A Multiple-Choice Quiz

Quiz overview
Build The Layer Structure
Create The Interface And Questions
Initialize The Quiz
Add Frame Labels
Scripting The Answer Buttons
Build The Quiz End
Try It Out

2) Variables

Creating Variables (a.k.a. Declaration)

Automatic Variable Creation
Legal Variable Names
Declare Variables At The Outset

Setting Variable Values (a.k.a. Assignment)
Changing and Retrieving Variable Values

Checking if a Variables Has No Value

Types of Values

Auotmatic Typing
Automatic Value Conversion
Determining The Type Manually

Variable Scope

When And Where Variables Are Accessible
Movie Clip Variables
Accessing Variables On Different Timelines
Movie Clip Variable Life Span
Local Variables

Some Applied Examples

3) ActionScript Data and Data Types

Data Versus Information
Retaining Meaning with Data Types

The ActionScript Data Types

Creating and Categorizing Data

Automatic Literal Typing
Automatic Complex Expression Typing

Data-Type Conversion

Automatic Type Conversion
Explicit Type Conversion
Conversion Duration
Flash 4 to Flash 5 Data-Type Conversion
Determining the Type of An Existing Datum

Primitive Data versus Composite Data

4) Primitive Data Types

The Number Type
Integers and Floating-Point Numbers
Numeric Literals

Integer Literals
Floating-point Literals
Special Values of the Number Data Type

Working with Numbers

Using Operators
Built-in Mathematical Functions

The String Type
Character Encoding
String Literals

The empty string
Escape sequences
Unicode Escape Sequences

Working with Strings

Joining strings together
Comparing Strings
Using Built-In String Functions
Character Indexing
Examining Strings
Retrieving Portions of Strings
Combining String Examination with Substring Extraction
Character Case Conversion
Character Code Functions
Executing Code in a String with Eval
Reference: Flash 4 vs Flash 5 String Operators and Functions

The Boolean Type

Using Boolean Values to Build a Preloader

Undefined
Null

5)Operators

General Features of Operators

Operators and Expressions
Number of Operands
Operator Precedence
Operator Associativity
Data Types and Operators

The Assignment Operator: =

Combining Operations with Assignment

Arithmetic Operators

Addition: +
Increment: ++
Subtraction: -
Decrement: --
Multiplication: *
Division: /
Modulo: %
Unary Negation: -

The Equals Operator: ==

Primitive Data Type Equality
Composite Data Type Equality
Equality and Data Type Conversion
The Does-Not-Equal Operator: !=
Common Uses of Equality Operations

The Comparison Operators

The Less-than Operator:
The Greater-than Operator:
The Less-than-or-equal Operator: <=
The Greater-than-or-equal Operator: >=
Comparison Operations and Data Type Conversion

The String Operators
The Logical Operators

Logical OR: ||
Logical AND:
Logical NOT: !
Logical Expressions and Data Values

The Grouping Operator: ()
The Comma Operator
The void Operator
The Bitwise Operators
Other Operators

The typeof Operator
The new Operator
The delete Operator
The Array-Element/Object-Property Access Operator: []
The Dot Operator
The Conditional Operator: ? :
The Function Call Operator: ()

6) Statements

Types of Statements
Statement Syntax

Statement Blocks

The ActionScript Statements

Loops and Conditionals
Expression Statements
The var Statement
The set Statement (aka Set Variable)
The function Statement
Function Call Statements
The call Statement
The return Statement
The with Statement
The ifFrameLoaded Statement
The Empty Statement

Statements versus Actions

7) Conditionals

The if Statement
The else Statement

TheConditional Operator

The else if Statement
Simulating the switch Statement
Compact Conditional Syntax

8) Loops

The while Statement
Loop Terminology
The do-while Statement
The for Statement

Multiple Iterators in for Loops

The for-in Statement
Stopping a Loop Prematurely

The break Statement
The continue Statement
Maximum Number of Iterations

Timeline and Clip Event Loops

Creating An Empty-Clip Timeline Loop
Flash 5 Clip Event Loops
Frame Rate’s Effect on Timeline Loops and Clip Event Loops

9) Functions

Creating Functions
Running Functions
Passing Information to Functions

Creating Functions with Parameters
Invoking Functions with Parameters

Exiting and Returning Values from Functions

Terminating a Function
Returning Values from Functions

Function Literals
Function Availability and Life Span

Function Availability
Function Life Span

Function Scope

The Scope Chain
Local Variables

Function Parameters Revisited

Number of Parameters
The arguments Object
Primitive versus Composite Parameter Values

Recursive Functions
Internal Functions

Internal Function Availability

Functions As Objects

Passing Functions to Functions

Centralizing Code

The Multiple-Choice Quiz Revisited

10) Events and Event Handlers

Synchronous Code Execution
Event-Based Asynchronous Code Execution
Types of Events
Event Handlers
Event Handler Syntax
Creating Event Handlers

Attaching Event Handlers to Buttons and Movie Clips
Attaching Event Handlers to Other Objects

Event Handler Scope

Movie Clip Event Handler Scope
Button Event Handler Scope
Other Object Event Handler Scope

Button Events

press
release
releaseOutside
rollOver
rollOut
dragOut
dragOver
keyPress

Movie Clip Events

enterFrame
load
unload
data
The User-Input Movie Clip Events
mouseDown
mouseUp
mouseMove
keyDown
keyUp

Order of Execution
Copying Clip Event Handlers
Refreshing the Screen with updateAfterEvent
Code Reusability
Dynamic Movie Clip Event Handlers
Event Handlers Applied

11) Arrays

What is an Array?
The Anatomy of an Array

Array Elements
Array Element Indexing
Array Size

Creating Arrays

The Array Constructor
Array Literals

Referencing Array Elements

Retrieving an Element's Value
Setting an Element's Value

Determining the Size of an Array
Named Array Elements

Creating and Referencing Named Array Elements
Removing Named Elements

Adding Elements to an Array

Adding New Elements Directly
Adding New Elements with the length Property
Adding New Elements with Array Methods

Removing Elements from an Array

Removing Elements with the delete Operator
Removing Elements with the length Property
Removing Elements with Array Methods

General Array-Manipulation Tools

The reverse Method
The sort Method
The slice Method
The join Method
The toString Method
Arrays as Objects

Multi-dimensional Arrays
The Multiple-Choice Quiz, Take 3

12) Objects and Classes

The Anatomy of an Object
Instantiating Objects
Object Properties

Referring to Properties
Using a for-in Loop to Access an Object's Properties

Methods
Classes and Object-Oriented Programming

Object Classes
Making A Class
Object Property Inheritance
Superclasses and Subclasses
Object-Oriented Programming Summary

The Built-in Classes and Objects of ActionScript

Built-in Classes
Built-in Objects
Learning the Ropes

13) Movie Clips

The "Objectness" of Movie Clips
Types of Movie Clips

Main Movies
Regular Movie Clips
Smart Clips
Process Clips
Script Clips
Linked Clips
Seed Clips

Creating Movie Clips

Movie Clip Symbols and Instances
Creating Instances
Instance Names
Importing External Movies

Movie and Instance Stacking Order

The Internal Layer Stack
The Programmatically Generated Clip Stack
The .swf Document "_level" Stack
Stacks and Order of Execution

Referring to Instances and Main Movies

Using Instance Names
Referring to the Current Instance or Movie
Referring to Nested Instances
Referring Main Movies with _root and _level
Authoring Instance References with Insert Target Path
Dynamic References to Clip Objects
Whither Tell Target?

Removing Movie Clip Instances and Main Movies

Using unloadMovie with Instances and Levels
Using removeMovieClip to Delete Instances
Removing Manually Created Instances Manually

Built-in Movie Clip Properties

What, No _color Property?

Movie Clip Methods

Creating Movie Clip Methods
Invoking Movie Clip Methods
Built-in Movie Clip Methods

Applied Movie Clip Examples

Build a Clock with Clips
The Last Quiz

14) Lexical Structure

Whitespace
Statement Terminators (aka Semicolons)
Comments
Reserved Words
Identifiers
Case Sensitivity

15) Advanced Topics

Copying, Comparing, and Passing Data
Bitwise Programming

Bitwise AND: &
Bitwise OR: |
Bitwise XOR: ^
Bitwise NOT: ~
The Bitwise Shift Operators: >, <, >
Bitwise Operations Applied

Advanced Function Scope Issues
The movieclip Data Type

PART II: Applied Actionscript

16) Using the Authoring Environment

The Actions Panel

Editing Modes

Adding Scripts to Frames
Adding Scripts to Buttons
Adding Scripts to Movie Clips
Where’s All the Code?
Productivity
Externalizing ActionScript Code

Import From File (Author-Time Import)
#include (Compile-Time Import)
Shared library (Run-Time Import)

Packaging Components as Smart Clips

Building a Smart Clip with a Standard Interface
Building a Smart Clip with a Customized Interface
Using Smart Clips

17) Flash Forms

The Flash Form Data-Cycle

Flash Client-Side User Input
Transmitting Data for Server-Side Processing
The Data-handling Application
Flash Receives and Interprets Results

Creating a Flash Fill-in Form

Building the Front End
Sending Data to the Server
The PERL Script, echo.pl
Receiving Results from the Server

18) On-screen Text Fieds

Dynamic Text Fields

Creating a Dynamic Text Field
Changing the Content of a Dynamic Text Field
Retrieving the Value of a Dynamic Text Field

User Input Text Fields

Creating a User Input Text Field
Changing the Content of an Input Text Field
Retrieving and Using the Value of an Input Text Field
User Input Text Fields and Forms

Text Field Options

Line Display
Variable
Border/Bg
Word Wrap
Selectable
Max Characters
Embed Fonts

Text Field Properties

The scroll Property
The maxscroll Property
Typical Text-Scrolling Code

HTML Support

(bold)
(italics)
(underline)
(font control)
(Paragraph break)
(Line break)
<A> (Anchor or Hypertext Link)
Anchor Tag Tab Order
Quoting Attribute Values
Unrecognized Tags and Attributes
Using HTML as Output
Using HTML as Input
Executing JavaScript from HTML Links
Calling ActionScript Functions from HTML Links

Working with Text Field Selections
Empty Text Fields and the for-in Statement

19) Debugging

Debugging Tools

The trace Function
The List Variables Command
The List Objects Command
The Bandwidth Profiler
The Debugger

Debugging Methodology

Recognizing Bugs
Identifying the Source of a Bug
Fixing Bugs

PART III: Language Reference

Alphabetical Listing of Global Functions, Global Properties, Classes, and Objects

Appendices

Appendix A: Resources

Appendix B: Latin 1 Character Repertoire and Key Codes

Appendix C: Backwards Compatibility

Appendix D: Differences Between ECMA-262, JavaScript, and ActionScript