Reactor Chat Tutorial, Part 2

Chat Example 2 adds the following new features to Chat Example 1:

Customizable user names
User join/leave messages
A user list

Here's what the new chat looks like:

Note: this example focuses on the Reactor API, and therefore shows only the bare minimum code required to create a chat user interface.

The Code

Here's the code for the new chat:

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package {
import flash.display.Sprite;
import flash.events.KeyboardEvent;
import flash.text.TextField;
import flash.text.TextFieldType;
import flash.ui.Keyboard;

import net.user1.reactor.Attribute;
import net.user1.reactor.IClient;
import net.user1.reactor.Reactor;
import net.user1.reactor.ReactorEvent;
import net.user1.reactor.Room;
import net.user1.reactor.RoomEvent;
import net.user1.reactor.SynchronizationState;

public class UnionChatPart2 extends Sprite {
// Union objects
protected var reactor:Reactor;
protected var chatRoom:Room;
// User interface objects
protected var incomingMessages:TextField;
protected var outgoingMessages:TextField;
protected var userlist:TextField;
protected var nameInput:TextField;

// Constructor
public function UnionChatPart2 () {
// Create the user interface
buildUI();
// Make the Reactor object
reactor = new Reactor();
// Run readyListener() when the connection is ready
reactor.addEventListener(ReactorEvent.READY,
readyListener);
// Connect to the server
reactor.connect("tryunion.com", 80);
}

// Method invoked when the connection is ready
protected function readyListener (e:ReactorEvent):void {
incomingMessages.appendText("Connected to Union\n");
chatRoom = reactor.getRoomManager().createRoom(
"chatRoom");
chatRoom.addMessageListener("CHAT_MESSAGE",
chatMessageListener);
chatRoom.addEventListener(RoomEvent.JOIN,
joinRoomListener);
chatRoom.addEventListener(RoomEvent.ADD_OCCUPANT,
addClientListener);
chatRoom.addEventListener(RoomEvent.REMOVE_OCCUPANT,
removeClientListener);
chatRoom.addEventListener(RoomEvent.UPDATE_CLIENT_ATTRIBUTE,
updateClientAttributeListener);
chatRoom.join();
}

// Create the user interface
protected function buildUI ():void {
incomingMessages = new TextField;
incomingMessages.border = true;
incomingMessages.background = true;
incomingMessages.width = 300;
incomingMessages.height = 200;

outgoingMessages = new TextField;
outgoingMessages.type = TextFieldType.INPUT;
outgoingMessages.border = true;
outgoingMessages.background = true;
outgoingMessages.width = 399;
outgoingMessages.height = 20;
outgoingMessages.y = 210;
outgoingMessages.addEventListener(KeyboardEvent.KEY_UP,
outgoingKeyUpListener);

userlist = new TextField();
userlist.border = true;
userlist.background = true;
userlist.width = 89;
userlist.height = 200;
userlist.x = 310;

nameInput = new TextField();
nameInput.type = TextFieldType.INPUT;
nameInput.border = true;
nameInput.background = true;
nameInput.width = 399;
nameInput.height = 20;
nameInput.y = 240;
nameInput.addEventListener(KeyboardEvent.KEY_UP,
nameKeyUpListener);

addChild(incomingMessages);
addChild(outgoingMessages);
addChild(userlist);
addChild(nameInput);
}

// Keyboard listener for outgoingMessages
protected function outgoingKeyUpListener (e:KeyboardEvent):void {
if (e.keyCode == Keyboard.ENTER) {
chatRoom.sendMessage("CHAT_MESSAGE",
true,
null,
outgoingMessages.text);
outgoingMessages.text = "";
}
}

// Keyboard listener for nameInput
protected function nameKeyUpListener (e:KeyboardEvent):void {
var self:IClient;
if (e.keyCode == Keyboard.ENTER) {
self = reactor.self();
self.setAttribute("username", nameInput.text);
nameInput.text = "";
}
}

// Method invoked when a chat message is received
protected function chatMessageListener (fromClient:IClient,
messageText:String
):void {
incomingMessages.appendText(getUserName(fromClient)
+ " says: "
+ messageText + "\n");
incomingMessages.scrollV = incomingMessages.maxScrollV;
}

// Method invoked when the current client joins the room
protected function joinRoomListener (e:RoomEvent):void {
updateUserList();
}

// Method invoked when a client joins the room
protected function addClientListener (e:RoomEvent):void {
if (e.getClient().isSelf()) {
incomingMessages.appendText("You joined the chat.\n");
} else {
if (chatRoom.getSyncState() != SynchronizationState.SYNCHRONIZING) {
// Show a "guest joined" message only when the room isn't performing
// its initial occupant-list synchronization.
incomingMessages.appendText(getUserName(e.getClient())
+ " joined the chat.\n");
}
}
incomingMessages.scrollV = incomingMessages.maxScrollV;
updateUserList();
}

// Method invoked when a client leave the room
protected function removeClientListener (e:RoomEvent):void {
incomingMessages.appendText(getUserName(e.getClient())
+ " left the chat.\n");
incomingMessages.scrollV = incomingMessages.maxScrollV;
updateUserList();
}

// Method invoked when any client in the room
// changes the value of a shared attribute
protected function updateClientAttributeListener (e:RoomEvent):void {
var changedAttr:Attribute = e.getChangedAttr();
if (changedAttr.name == "username") {
if (changedAttr.oldValue == null) {
incomingMessages.appendText("Guest" + e.getClientID());
} else {
incomingMessages.appendText(changedAttr.oldValue);
}
incomingMessages.appendText(" 's name changed to "
+ getUserName(e.getClient())
+ ".\n");
incomingMessages.scrollV = incomingMessages.maxScrollV;
updateUserList();
}
}

// Helper method to display the room's
// clients in the user list
protected function updateUserList ():void {
userlist.text = "";
for each (var client:IClient in chatRoom.getOccupants()) {
userlist.appendText(getUserName(client) + "\n");
}
}

// Helper method to retrieve a client's user name.
// If no user name is set for the specified client,
// returns "Guestn" (where 'n' is the client's id).
protected function getUserName (client:IClient):String {
var username:String = client.getAttribute("username");
if (username == null) {
return "Guest" + client.getClientID();
} else {
return username;
}
}
}
}