Writing ASP Chat using JavaScript and XML (Part 4)

<script language="JavaScript" runat="server" src="Settings.js"></script>
<script language="JavaScript" runat="server" src="MessagesClass.js"></script>
<script language="JavaScript" runat="server" src="LimitedXmlClass.js"></script>
<script language="JavaScript" runat="server" src="IncorrectInputFilter.js"></script>
<script language="JavaScript" runat="server" src="SessionClass.js"></script>
<script language="JavaScript" runat="server" src="SharedXMLClass.js"></script>
<script language="JavaScript" runat="server" src="SingleLevelXMLClass.js"></script>
<script language="JavaScript" runat="server" src="UserManagerClass.js"></script>
<script language="JavaScript" runat="server" src="UsersDataXMLClass.js"></script>
<script language="JavaScript" runat="server" src="UserInfoClass.js"></script>
<script language="JavaScript" runat="server" src="RoomsDataXMLClass.js"></script>
<script language="JavaScript" runat="server" src="RoomInfoClass.js"></script>
<script language="JavaScript" runat="server">
/**
 *  Addition of a new message for the chat.
 */
function addMessage(roomID, sessionID, strMessage, moodType) {
	var clientIP = Request.ServerVariables("REMOTE_ADDR");
	var objMessages = new Messages;
	var strNick = getUserNick(roomID, sessionID);
	if(typeof(strNick) != "undefined") {
		objMessages.addMessage(roomID, clientIP, strNick, strMessage, moodType)
	}
}

/**
 *  Addition of a new system message for the chat.
 */
function addSysMessage(roomID, strMessage) {
	var objMessages = new Messages;
	objMessages.addSysMessage(roomID, strMessage)
}

/**
 *  Formats all messages as HTML for user friendly representation.
 */
function formatAll(roomID) {
	var objMessages = new Messages;
	var strMessages = objMessages.formatAll(roomID);
	return strMessages;
}

/**
 *  Adds user to active users list.
 *  @return Session unique id or -1 if fails.
 */
function loginUser(strUserName, password) {
	var sessionID = -1;
	strUserName = Server.HTMLEncode(strUserName);
	password = Server.HTMLEncode(password);
	var isValidUser = authenticateUser(strUserName, password);
	if(isValidUser) {
		var userManager = new UserManager;
		var clientIP = Request.ServerVariables("REMOTE_ADDR");
		sessionID = userManager.loginUser(strUserName, clientIP);
	}
	return sessionID;
}

/**
 *  Cheks user name and password combination.
 *  @return true if valid user, overvise false.
 */
function authenticateUser(userName, password) {
	var usersData = new UsersDataXML;
	return usersData.authenticateUser(userName, password);
}

/**
 *  Registers new user.
 *  @return New user id or -1 if already exists.
 */
function registerUser(nick, password, firstName, 
					  lastName, email) {
	var usersData = new UsersDataXML;
	nick = Server.HTMLEncode(nick);
	password = Server.HTMLEncode(password);
	firstName = Server.HTMLEncode(firstName);
	lastName = Server.HTMLEncode(lastName);
	email = Server.HTMLEncode(email);
	return usersData.registerUser(nick, password, firstName, 
		lastName, email);
}

/**
 *  Removes user from active users list.
 *  @param session unique id.
 */
function logoutUser(roomID, sessionID) {
	var userManager = new UserManager;
	if(sessionID > -1) {
		var strUserName = userManager.getUserNick(roomID, sessionID);
		if(typeof(strUserName) != "undefined") {
			userManager.removeSession(roomID, sessionID);
			var strMessage = strUserName + " went from here!"
			addSysMessage(roomID, strMessage);
		}
	}
}

/**
 *  Extracts user name by session id.
 */
function getUserNick(roomID, sessionID) {
	var userManager = new UserManager;
	return userManager.getUserNick(roomID, sessionID);
}

/**
 *  Formats users list for specified session.
 */
function formatUsers(roomID, sessionID) {
	var userManager = new UserManager;
	return userManager.formatUsers(roomID, sessionID);
}

/**
 *  Retrieves quantity of currently logged users in the specified room.
 */
function getActiveUsersCount(roomID) {
	var userManager = new UserManager;
	return userManager.getUsersCount(roomID);
}

/**
 *  Formats html representation of available rooms with quantity 
 * of active users for each.
 */
function formatAllRooms() {
	var allRoomsFormat = "";
	var roomsData = new RoomsDataXML;
	var roomsList = roomsData.getRoomsList();
	var i = 0;
	for(i = 0; i < roomsList.length; i++) {
		var x = roomsList.item(i);
		var info = new RoomInfo(x);
		var roomID = info.getRoomID();
		var nUsers = getActiveUsersCount(roomID);
		var roomFormat = "<tr><td><a href=\"javascript:goToRoom("
			+ roomID + ")\">" + info.getRoomName()
			+ "</a></td><td>" + nUsers
			+ "</td></tr>\n";
		allRoomsFormat += roomFormat;
	}
	return allRoomsFormat;
}

/**
 *  Checks for session in specified room presence.
 *  @return true if session exists, overwise false.
 */
function isValidSession(roomID, sessionID) {
	var userManager = new UserManager;
	return userManager.isValidSession(roomID, sessionID);
}

/**
 *  Create a new chat room.
 */
function createRoom(sessionID, roomName) {
	var isValid = isValidSession(0, sessionID);
	if(isValid) {
		var roomsData = new RoomsDataXML;
		return roomsData.createRoom(roomName);
	}
}

/**
 *  Enter just logged user to the room.
 */
function enterToTheRoom(roomID, sessionID) {
	return switchRoom(0, roomID, sessionID);
}

/**
 *  Move user to another room.
 */
function switchRoom(roomIDOld, roomIDNew, sessionID) {
	var strUserName = getUserNick(roomIDOld, sessionID);
	var userManager = new UserManager;
	var alreadyExist = userManager.getSessionID(roomIDNew, strUserName);
	if(alreadyExist == -1 && sessionID > -1) {
		userManager.switchRoom(roomIDOld, roomIDNew, sessionID);
		strMessage = "Welcome " + strUserName + "!"
		addSysMessage(roomIDNew, strMessage);
		return sessionID;
	}
	else {
		// User already in target room. Required only removing from previous.
		userManager.removeSession(roomIDOld, sessionID);
		// Provide existent session no.
		return alreadyExist;
	}
}

/**
 *  Clone session for another room.
 */
function copySessionToRoom(roomIDOld, roomIDNew, sessionID) {
	var userManager = new UserManager;
	var strUserName = getUserNick(roomIDOld, sessionID);
	var alreadyExist = userManager.getSessionID(roomIDNew, strUserName);
	if(alreadyExist == -1) {
		userManager.copySessionToRoom(roomIDOld, roomIDNew, sessionID);
		return sessionID;
	}
	else {
		return alreadyExist;
	}
}
</script>