Programming Flash Communication Server

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Chapter 3: Managing Connections

Placing the main.asc file from Example 3-13 into an applications subdirectory named

netConnectChat allows this server-side main.asc script to control the netConnectChat

application. If you were developing the main.asc script, you could always test it with

a test client but let’s push on to create the client-side part of the netConnectChat

application in the next section.

Building the Client

Let’s build a Flash movie to connect to our brand new netConnectChat application.

For now, we’ll stick with ActionScript 1.0 and the v1 UI components on which Mac-

romedia’s communication components rely. In Chapter 13, when we develop our

own custom communication components, we’ll switch to ActionScript 2.0 and the

v2 UI components.

Using Macromedia’s communication components without SimpleConnect is a two-

step process: establish a network connection to the application instance and then

pass the NetConnection object to each component’s connect( ) method. The netCon-

nectChat application uses the PeopleList, Chat, and UserColor components to create

a simple text chat interface. The interface can be created with everything on a single

frame, as is popular when using the SimpleConnect component, or the different

states of the movie can be spread over the timeline. The book’s web site includes an

example of a single-frame movie. In this example, we’ll build the client-side movie

for this application using the timeline. Figure 3-4 shows the timeline and Stage when

the movie is on the

Chat frame.

The

Chat frame includes the following movie clips (components) and text field:

chat_mc

A Chat component instance

peopleList_mc

A PeopleList component instance

userColor_mc

A UserColor component instance

userName_txt

The text field at the bottom of the Stage

application.acceptConnection(client);

};

// When a client disconnects, remove the username from the

// users hash so someone can use it again.

application.onDisconnect = function (client) {

var userName = gFrameworkFC.getClientGlobals(client).username;

delete users[userName];

};

Example 3-13. The main.asc file for the netConnectChat application (continued)

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Communication Components Without SimpleConnect

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connect_btn

The Connect button at the bottom of the Stage

The

Login frame contains only the userName_txt field and connect_btn button. If we

were using the SimpleConnect component to log in the user, any other communica-

tion component would have to exist throughout the same timeline frames as Simple-

Connect. In this example, the communication components do not need to be on the

same frames as the username field or the Connect button. The components need

only a NetConnection to function, so the username field and Connect button don’t

have to be included in the

Chat frame either. However, in the Chat state, we change

the Connect button label to Disconnect; the button logs out the user when clicked.

The username text field is kept on the Stage to show the current user’s name, but it is

disabled during the chat.

The Scripts layer contains all but two lines of the script for the movie. The three

important frames are the

Init frame, which contains most of the script, and the

Login and Chat frames. When the script on the Init frame has completed executing,

the playhead moves to the

Login frame. There is only one line of code on the Login

frame of the Scripts layers:

startLoginState( );

This statement calls the startLoginState( ) function declared in the first frame of the

timeline to initialize the elements on the Stage:

function startLoginState ( ) {

connect_btn.setLabel("Connect");

userName_txt.selectable = true;

}

Figure 3-4. The timeline and Stage with the playhead on the Chat frame