Programming Flash Communication Server

This is the Title of the Book, eMatter Edition

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

The Life of an Application Instance

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Notice that there are two key objects related to instance and client management. The

application object is a singleton object—there is only one—that represents the

application instance. Each instance gets its own

application object, which is an

instance of the Application class. As shown in Example 4-2, you should add dynamic

methods directly to the singleton instance,

application, instead of Application.

prototype

. For example:

application.onConnect = function (client, userName, password) {};

A Client object represents a client-side Flash movie attempting to connect to an

application instance. There can be more than one Client object (one for each user)

for each

application object. The methods and properties of the Application and Cli-

ent classes are described in Macromedia’s Server-Side Communication ActionScript

Dictionary (available from http://download.macromedia.com/pub/flashcom/

documentation/FlashCom_SS_ASD.pdf).

Here is the startup sequence:

1. The main.asc file is loaded, compiled, and executed.

2. Any files that were included using the load( ) method are loaded and executed.

In turn, these files may load other files.

3. The application.onAppStart( ) method is called. The onAppStart( ) method is

called only once and is often used to initialize the

application object and the

instance’s shared object and stream resources.

4. If the instance has been started as a result of a client connection request using

NetConnection.connect( ), the application.onConnect( ) method is called and

passed a Client object, representing the client Flash movie that tried to connect.

Any optional parameters passed into connect( ) are also forwarded to the onCon-

nect( ) method, where the client’s connection request can be rejected, accepted,

or left pending.

Midlife

Once the application instance has started, any number of clients can connect and

disconnect from the instance. Whenever a Flash movie attempts to connect, the

application.onConnect( ) method is called and passed a new Client object represent-

ing the client-side Flash movie. Client objects with accepted connections are kept in

the

application.clients array. Whenever an accepted client disconnects, the appli-

cation.onDisconnect( ) method is called and passed a Client object that represents the

client that has disconnected. A client can be disconnected due to network problems

or problems on a remote workstation. FlashCom may not realize immediately that

the client has disconnected. So, it is possible that, for a time, a Client object will not

always represent a connected movie.