HABTM dropdown items not selected - cakephp

Question

I created a site for fun to learn CakePHP but for some reason I can't get a multiple select dropdown box to show my selected items. In this example 1 video game can have multiple difficulties (easy, normal, hard). On my Game edit page I have a multi select box to pick the difficulties. It shows all three difficulties and I can select them and it saves correctly. However when I return to the edit page the items I previously saved do not show highlighted as selected. I have verified that the records are saving correctly in the database.
Tables:
games
difficulties
difficulties_games
Models:
class Game extends AppModel {
public $actsAs = array('Containable');
public $hasAndBelongsToMany = array(
'Difficulty' =>
array(
'className' => 'Difficulty',
'joinTable' => 'difficulties_games',
'foreignKey' => 'game_id',
'associationForeignKey' => 'difficulty_id',
'unique' => 'true'
)
);
}
class Difficulty extends AppModel {
public $actsAs = array('Containable');
public $hasAndBelongsToMany = array(
'Game' =>
array(
'className' => 'Game',
'joinTable' => 'difficulties_games',
'foreignKey' => 'difficulty_id',
'associationForeignKey' => 'game_id',
'unique' => 'true'
)
);
}
Controller:
$game = $this->Game->findById($id);
$this->set('difficulties', $this->Game->Difficulty->find('list'));
View (edit.ctp):
echo $this->Form->input('Difficulty');
This has to be something simple I am missing but I've read through the book on HABTM and searched here and couldn't find much on multi-select boxes.
UPDATE:
Here is the entire edit function in the controller:
public function edit($id = null) {
if (!$id) {
throw new NotFoundException(__('Invalid post'));
}
$game = $this->Game->findById($id);
if (!$game) {
throw new NotFoundException(__('Invalid post'));
}
if ($this->request->is('post') || $this->request->is('put')) {
$this->Game->id = $id;
if ($this->Game->saveAll($this->request->data)) {
$this->Session->setFlash('Your game has been updated.');
$this->redirect(array('action' => 'index'));
} else {
$this->Session->setFlash($this->Game->invalidFields());
}
}
if (!$this->request->data) {
$this->request->data = $game;
}
$this->set('systems', $this->Game->System->find('list'));
$this->set('genres', $this->Game->Genre->find('list'));
$this->set('difficulties', $this->Game->Difficulty->find('list'));
}
Also here is some more on the View:
echo $this->Form->create('Game');
echo $this->Form->input('name');
echo $this->Form->input('system_id');
echo $this->Form->input('genre_id');
echo $this->Form->input('Difficulty');
echo $this->Form->input('id', array('type' => 'hidden'));
echo $this->Form->end('Save Game');

Answer 1

What CakePHP version are you using? Releases 2.2.6 and 2.3.0 have a bug related to showing existing habtm selected. So updated to 2.2.7 if using 2.2.6 or if using 2.3.0 use the master branch from github until the next bugfix release is done.

Answer 2

For everyone who sets public $recursive = -1; in his AppModel due to performance reasons, or changes the recursion in his controller:
The automagic won't work without recursive 1! Make sure you change it in the options when retreiving your data for the edit.
$options = array(
'recursive' => 1,
'conditions' => array('YourModel.' . $this->YourModel->primaryKey => $id)
);
$this->request->data = $this->YourModel->find('first', $options);