Writing ASP Chat using JavaScript and XML (Part 4)

function UsersDataXML() {
	this.authenticateUser = UsersDataXML_authenticateUser;
	this.save = UsersDataXML_save;
	this.initialize = UsersDataXML_initialize;
	this.autoSave = UsersDataXML_autoSave;
	this.registerUser = UsersDataXML_registerUser;
	this.findUser = UsersDataXML_findUser;
	this.filePath = getUsersDataPath();
	this.autoSaveInterval = getAutoSaveInterval();// In seconds.
	this.identifier = "UsersStore";
}

/**
 *  Cheks user name and password combination.
 *  @return true if valid user, overvise false.
 */
function UsersDataXML_authenticateUser(userName, password) {
	var usersStore = new SharedXML(this.identifier);
	var xmlNode = usersStore.findNodeByName(userName);
	if(xmlNode != null) {
		var user = new UserInfo(xmlNode);
		return user.checkPassword(password);
	}
	return false;
}

/**
 *  Searching for an existing user by nick. 
 *  @param strNick user nick.
 *  @return Found user object or undefined, if not exists.
 */
function UsersDataXML_findUser(strNick) {
	var usersStore = new SharedXML(this.identifier);
	var xmlNode = usersStore.findNodeByName(strNick);
	if(xmlNode != null)
	{
		var user = new UserInfo(xmlNode);
		return user;
	}
}

/**
 *  Saves data to disk.
 */
function UsersDataXML_save() {
	var usersStore = new SharedXML(this.identifier);
	usersStore.save(this.filePath);
}

/**
 *  Initial data load.
 */
function UsersDataXML_initialize() {
	var usersStore = new SharedXML(this.identifier);
	usersStore.load(this.filePath);
}

/**
 *  Checking for autosave timeout elapsed. If true, saves data.
 */
function UsersDataXML_autoSave() {
	this.save();
}

/**
 *  Adds new user to store.
 *  @return New user id or -1 if already exists.
 */
function UsersDataXML_registerUser(nick, password, firstName, 
								   lastName, email) {
	var user = this.findUser(nick);
	if(typeof(user) != "undefined") {
		// User already exists.
		return -1;
	}
	var usersStore = new SharedXML(this.identifier);
	var xmlNode = usersStore.addNode();
	var newUser = new UserInfo(xmlNode);
	newUser.setUserNick(nick);
	newUser.setPassword(password);
	newUser.setFirstName(firstName);
	newUser.setLastName(lastName);
	newUser.setEmail(email);

	var id = newUser.getUserID();
	this.autoSave();
	return id;
}