Programming Flash Communication Server

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Chapter 4: Applications, Instances, and Server-Side ActionScript

Two instances should never directly attempt to update the same

shared object. If more than one instance needs to use a shared object,

it should be done via a NetConnection between the instances.

Usually, one instance is selected as the owner of the shared object or stream and the

other instances connect to it in order to access its resources. Interinstance communi-

cations is covered in detail later in this chapter and in Chapter 16.

Differences Between Flash ActionScript and

Server-Side ActionScript

As alluded to earlier in this chapter and the Preface, there are two distinct types of

ActionScript: client-side ActionScript—which includes both ActionScript 1.0 and

ActionScript 2.0—and the server-side version, known as Server-Side ActionScript.

Client-side ActionScript is used to create .swf movies, which run in the Flash Player

on the user’s machine. Server-Side ActionScript is stored in .asc files that run on the

FlashCom Server.

Since Flash 5, client-side ActionScript has been based on the ECMA (European Com-

puter Manufacturers Association) standards, as is JavaScript. The standard language

is named ECMAScript and is defined in ECMA-262 available at: http://www.ecma-

international.org. Client-side Flash ActionScript has never completely conformed to

the ECMAScript standard because Macromedia developed the language with its

unique needs and backward compatibility in mind. Client-side ActionScript has also

evolved over time. The earlier implementation supported in Flash MX (and still sup-

ported in Flash MX 2004) has been retroactively dubbed ActionScript 1.0. The latest

implementation—supported in Flash MX 2004 and closer to ECMA compliance

than earlier implementations—is named ActionScript 2.0. For more information on

the differences between Flash ActionScript 1.0 and ECMAScript, see Appendix D in

ActionScript for Flash MX: The Definitive Guide (O’Reilly). For details on

ActionScript 2.0 and how it diverges from the ECMA standards, see Essential Action-

Script 2.0, also from O’Reilly.

Contrary to client-side ActionScript, Server-Side ActionScript conforms to the

ECMAScript standard because Macromedia used the Mozilla Spidermonkey

JavaScript 1.5 interpreter in FlashCom. More information on it and JavaScript 1.5

are available here:

http://www.mozilla.org/js

This section outlines the differences that you should watch out for between client-

side ActionScript and Server-Side ActionScript.