validation in cakephp 3.0

AppController.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         0.2.9
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace App\Controller;

use Cake\Controller\Controller;
use Cake\Controller\Component\Auth;
use Cake\Controller\Component\Auth\BlowfishPasswordHasher;
/**
 * Application Controller
 *
 * Add your application-wide methods in the class below, your controllers
 * will inherit them.
 *
 * @link http://book.cakephp.org/3.0/en/controllers.html#the-app-controller
 */
class AppController extends Controller {
 public $components = [
        'Session',
        'Auth' => [
            'loginRedirect' => [
                'controller' => 'articles',
                'action' => 'index'
            ],
            'logoutRedirect' => [
                'controller' => 'pages',
                'action' => 'display',
                'home'
            ],
			/* 'authenticate' => [
				'Form' => [
					'passwordHasher' => 'Blowfish'
				]
			] */
        ]
    ];

    public function beforeFilter() {
        $this->Auth->allow(['add', 'logout']);
		$this->Auth->config('authenticate', ['Form'=>['username'=>'email','password'=>'password']]);
		//$pass = (new BlowfishPasswordHasher)->hash($this->request->data['password']);
		//$this->request->data['password'] = $pass;
		//pr($pass);exit;
    }
}

User.php

<?php 
//App\Model\Entity\User.php
namespace App\Model\Entity;

use Cake\ORM\Entity;
use Cake\Controller\Component\Auth\BlowfishPasswordHasher;

class User extends Entity {
    public function setPassword($password) {
        return (new BlowfishPasswordHasher)->hash($password);
    }

}
?>

UsersController.php

<?php 
//App\Controller/UsersController.php
namespace App\Controller;

use App\Controller\AppController;
use Cake\Error\NotFoundException;

class UsersController extends AppController {
	public $helpers = ['Form', 'Html'];
    public function beforeFilter(Event $event) {
        parent::beforeFilter($event);
        $this->Auth->allow('add');
		$this->Auth->authError = "Login failed. Invalid email or password.";
    }
	public function index() {
		
        $this->set('users', $this->Users->find('all'));
    }
	
    public function view($id) {
        if (!$id) {
            throw new NotFoundException(__('Invalid user'));
        }

        $user = $this->Users->get($id);
        $this->set(compact('user'));
    }

    public function add() {
        $user = $this->Users->newEntity($this->request->data);
        if ($this->request->is('post')) {
            if ($this->Users->save($user)) {
                $this->Session->setFlash(__('The user has been saved.'));
                return $this->redirect(['action' => 'index']);
            }
            $this->Session->setFlash(__('Unable to add the user.'));
        }
        $this->set('user', $user);
    }
	public function login() {
		if ($this->request->is('post')) {
			if ($this->Auth->login()) {
				return $this->redirect($this->Auth->redirectUrl());
			} else {
				$this->Session->setFlash(
					__('email or password is incorrect'),
					'default',
					array(),
					'auth'
				);
			}
		}
	}
	public function logout() {
		return $this->redirect($this->Auth->logout());
	}
}
?>

UsersTable.php

<?php
//App\Model\Table\UsersTable.php
namespace App\Model\Table;

use Cake\ORM\Table;
use Cake\Validation\Validator;
$validator = new Validator();
class UsersTable extends Table {
	public function initialize(array $config) {
        $this->addBehavior('Timestamp');
    }
    public function validationDefault(Validator $validator) {
      return $validator->notEmpty('email', 'A email is required')
             ->notEmpty('password', 'A password is required')
			->notEmpty('role', 'A password is required')
            /* ->add('role', [
                'rule' => ['inList', ['admin', 'author']],
                'message' => 'Please enter a valid role'
            ]) */;
    } 
}
?>