balance/modules/profile/scripts/login.php

<?php
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * PROFILE MANAGER - LOGIN
 * 
 * Attempt to login.
 * 
 * @author s.khudikyan
**/
$module = App::Get()->loadModule();

// Get instance of authentication class
$authentication = App::Get()->getAuthenticationProvider();

$message = '';

// If a user is already logged in, redirect to home page
if( $authentication->isLoggedIn() ) App::Get()->Redirect(SITE_ROOT . "/"); 

// Otherwise, if a user is attempting to log in, process:
else if(isset($_POST["username"]) && isset($_POST["password"])) {

	// Check the provided login credentials:
	if($authentication->login($_POST["username"], $_POST["password"])){
  	 	App::Get()->Redirect(SITE_ROOT . "/" ); // login successful
  	 } else {
  	 	App::Get()->SetMessage("Invalid Credentials Provided",CAS_MSG_ERROR);
  	 	App::Get()->Redirect($module->moduleRoot . "/login");
  	 }
}