cake php, undefined variable problem

i have a controller page like this:

class UsersController extends AppController开发者_如何学Python {
var $helpers = array ('Html','Form');
var $name = 'Users';

function index() {
    $this->set('view_users', $this->User->find('all'));
}
}

then i have another controller page like this:

    class PostsController extends AppController {
var $helpers = array ('Html','Form');
var $name = 'Posts';

function index() {
    $this->set('edit_users', $this->Post->find('all'));
}
}

then i have the index file:

<?php foreach($view_users as $value): ?>
<p>id - <?php echo $value['User']['first']; ?></p>
<?php endforeach; ?>

<?php foreach($edit_users as $value): ?>
<p>id - <?php echo $value['Post']['first']; ?></p>
<?php endforeach; ?>

the problem i get is :Notice (8): Undefined variable: view_users [APP\views\posts\index.ctp, line 6]

very strange since the edit_users var works.

What can be the problem? thanks

The UsersController and the PostsController are different controllers. They use different views and even though they both have an index action, they are called separately and use different views.

When you go to /users/index, it calls the index action of the UsersController which sets the $view_users variable.

When you go to /posts/index, it calls in the index action of the PostsController which sets the $edit_users.

The problem: You PostsController login action isn't setting a value for $view_users so the variable is undefined. Assuming that you Post model has a relationship with the User model, you should be able to add this to the PostsController index action to solve your problem:

$this->set('view_users', $this->Post->User->find('all'));

Alternatively, you could change the view to use empty to check if the variable was set first:

if ( ! empty($view_users) )
  foreach ( $view_users as view_user )
  {
    // Do something useful.
  }