An Overview of ActionScript The Powerful Scripting Language of Macromedia Flash

History: Purpose Front End Development Character Animations Rich Application Development – Web Services Motion Graphics

History: Author Macromedia – Flash Engineering Team Approachable Creative Power Gary Grossman – Senior Engineering Manager, Macromedia Flash Team

History: Macromedia Flash Vector Animation Tool Mostly Web Deployed – Flash Player Enjoys a 98% of the World’s browsers support Evolved into a rich client delivery vehicle

Flash and ActionScript ActionScript is the Scripting language developed for Flash Most notably handles interactions and event-handling in flash Has access to full capabilities of Flash

Flash and ActionScript -Macromedia Flash Interface -- Concept of a timeline

Flash and ActionScript Actions Frame Good Program- ming practice

History: ECMA-262 Based on several originating technologies – JavaScript(Netscape) – Jscript(Microsoft) Invented by Brendan Eich at Netscape Started Development: November 1996 Approved as international standard: April 1998

History: ECMAScript Scripting Language Originally designed for the Web Object based – Cluster of Communicating Objects

History: ECMAScript Built-in types: – Undefined – Null – Boolean – Number – String – Object

History: ECMAScript Built-in objects: – Global – Function – Array – String – Boolean – Number – Date – Math

History: ECMAScript Built-in Operators – Unary – Multiplicative – Additive – Relational

ActionScript Flash MX runs ActionScript version 6 (MX) Differs slightly from the ECMA-262 standard

Differences from ECMAScript Exception Handling String to Boolean conversion Case sensitivity Function Constructor Date Object

Differences from JavaScript Object Model Undeclared Variables Invoking Undeclared Variables

Lexical Structure Whitespace Statement Terminators Comments Reserved Words Identifiers Case Sensitivity

Features: Strengths Cross-Platform Consistency High-level Abstraction Massive Developer base Massive Web use Object-Oriented – Inheritance Polymorphism

Features: Weaknesses Limitations – Flash Scripting language Proprietary Flash Player Exception Handling

Sample Implementations Kartoo Neostream Interactive

Flash Player Not open source Flash Player Specification License – May have been developed in several languages – Portable C++ source code version – Hint of java

SWF file format Open Source Designed with the following in mind: – On-screen Display – Extensibility – Network Delivery – Simplicity – File Independence – Scalability – Speed SWF file format –

Links ashremoting ashremoting

Resources ActionScript for Flash MX: The Definitive Guide – Colin Moock, O’Reilly Publications Macromedia Flash Support Site – ECMA Language Specifications – files/ecma-st/Ecma-262.pdf