在非对象授权上调用成员函数allow()

Question

我使用了这个教程:http://book.cakephp.org/2.0/en/tutorials-and-examples/blog-auth-example/auth.html

构建我的第一个表单/创建用户应用程序，但它失败了一个错误消息:

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

这是第18行:

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

上面的行是函数的成员:

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

我的整个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'));
    }
}
?>

为什么会发生?

Answer 1

确保在你的AppController中调用了Auth组件。如果你没有AppController，在Controllers目录下创建AppController.php，代码如下:

<?php
  class AppController extends Controller {
  }
?>

Auth组件在AppController的公共变量中被调用，所以控制器应该是这样的:

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

Auth现在可以在整个应用程序中使用。你也可以在你的UsersController中调用AuthComponent，但是这会使它只对那个特定的控制器可用。您可能希望在整个应用程序中使用身份验证。