Call to a member function allow() on a non-object - authorization

Question

I used this tutorial: http://book.cakephp.org/2.0/en/tutorials-and-examples/blog-auth-example/auth.html

To build my first form/create user app, but it fails with an error message:

Fatal error: Call to a member function allow() on a non-object in /home/public_html/cake/app/Controller/UsersController.php on line 18

This ius the 18 line:

$this->Auth->allow('add', 'logout');

The above line is a member of function:

public function beforeFilter() {
    parent::beforeFilter();
    $this->Auth->allow('add', 'logout');
}

My whole UsersController.php:

<?php
class UsersController extends AppController {

    public function login() {
        if ($this->Auth->login()) {
            $this->redirect($this->Auth->redirect());
        } else {
            $this->Session->setFlash(__('Invalid username or password, try again'));
        }
    }

    public function logout() {
        $this->redirect($this->Auth->logout());
    }

    public function beforeFilter() {
        parent::beforeFilter();
        $this->Auth->allow('add', 'logout');
    }

    public function index() {
        $this->User->recursive = 0;
        $this->set('users', $this->paginate());
    }

    public function view($id = null) {
        $this->User->id = $id;
        if (!$this->User->exists()) {
            throw new NotFoundException(__('Invalid user'));
        }
        $this->set('user', $this->User->read(null, $id));
    }

    public function add() {
        if ($this->request->is('post')) {
            $this->User->create();
            if ($this->User->save($this->request->data)) {
                $this->Session->setFlash(__('The user has been saved'));
                $this->redirect(array('action' => 'index'));
            } else {
                $this->Session->setFlash(__('The user could not be saved. Please, try again.'));
            }
        }
    }

    public function edit($id = null) {
        $this->User->id = $id;
        if (!$this->User->exists()) {
            throw new NotFoundException(__('Invalid user'));
        }
        if ($this->request->is('post') || $this->request->is('put')) {
            if ($this->User->save($this->request->data)) {
                $this->Session->setFlash(__('The user has been saved'));
                $this->redirect(array('action' => 'index'));
            } else {
                $this->Session->setFlash(__('The user could not be saved. Please, try again.'));
            }
        } else {
            $this->request->data = $this->User->read(null, $id);
            unset($this->request->data['User']['password']);
        }
    }

    public function delete($id = null) {
        if (!$this->request->is('post')) {
            throw new MethodNotAllowedException();
        }
        $this->User->id = $id;
        if (!$this->User->exists()) {
            throw new NotFoundException(__('Invalid user'));
        }
        if ($this->User->delete()) {
            $this->Session->setFlash(__('User deleted'));
            $this->redirect(array('action'=>'index'));
        }
        $this->Session->setFlash(__('User was not deleted'));
        $this->redirect(array('action' => 'index'));
    }
}
?>

Why does it happends?

Solution

Make sure the Auth compenent is actually called in your AppController. If you don't have an AppController create AppController.php in your Controllers directory with the following code:

<?php
  class AppController extends Controller {
  }
?>

The Auth component is called in a public variable in the AppController, so the controller would look like this:

<?php
  class AppController extends Controller {
    public $components = array('Auth');
  }
?>

Auth is now available throughout your application. You could also call the AuthComponent in your UsersController, but that would make it only available to that particular controller. You probably want to use authentication in your entire application.