Cakephp HABTM saving -.- - cakephp

Question

I'm googling high and low on this. I'm not sure where i went wrong cause I don't get any errors.
i have 3 tables:
MOVIES - id, title, genre, etc
GENRES - id, genre
GENRES_MOVIES - movie_id, genre_id
Movie model:
public $hasAndBelongsToMany = array(
'Genre' => array(
'className' => 'Genre',
'joinTable' => 'genres_movies',
'foreignKey' => 'movie_id',
'associationForeignKey' => 'genre_id'
)
);
View:
echo $this->Form->create('Movie', array('controller' => 'movies', 'action' => 'add', 'type' => 'file'));
echo $this->Form->input('title');
echo $this->Form->input('description', array('type' => 'textarea');
echo $this->Form->input('imdb_url');
echo $this->Form->year('release_year', 1900, date('Y'));
echo $this->Form->input('length', array('type' => 'number'));
echo $this->Form->input('genre', array('type'=>'select', 'multiple'=>'checkbox', 'options'=> $genres));
echo $this->Form->input('image', array('type' => 'file'));
echo $this->Form->button('Submit');
MoviesController:
public function add()
{
/* for populating checkbox */
$this->set('genres', $this->Movie->Genre->find('list', array('fields' => array('Genre.id', 'Genre.genre'))));
if($this->request->is('post'))
{
$data_movie = array(
'title' => $this->request->data['Movie']['title'],
'description' => $this->request->data['Movie']['description'],
'imdb_url' => $this->request->data['Movie']['imdb_url'],
'release_year' => (int)$this->request->data['Movie']['release_year']['year'],
'length' => (int)$this->request->data['Movie']['length'],
'user_id' => (int)$this->Auth->user('id')
);
$data_genre = array('Genre' => array());
foreach($this->request->data['Movie']['genre'] as $genre)
array_push($data_genre['Genre'], (int)$genre);
$data = array('Movie' => $data_movie, 'Genre' => $data_genre);
$this->Movie->create();
if($this->Movie->save($data)
{
echo 'success';
}
}
}
So, why did I bother setting up data manually for saving in the movieController, it is because the tutorials are telling me data should be organised like it is now (before that it looked a little different.. so i tried and this is what i have now (it looks ok to me)
http://s10.postimg.org/ikewszo95/Untitled_1.jpg
you can see the form here http://marko-stimac.iz.hr/temp/movies/movies/add (although submit wont work, i guess it is because of the Auth component not letting non-registered users)
hm any help would be greeatly appreciated :)
EDIT - updated controller
public function add()
{
$this->set('genres', $this->Movie->Genre->find('list', array('fields' => array('Genre.id', 'Genre.genre'))));
if($this->request->is('post'))
{
($this->Movie->saveAssociated($this->request->data))
{
$this->redirect('/');
$this->Session->setFlash('Success.');
}
}
}

Answer 1

Don't modify the data, that is, get rid of these lines
$data_genre = array('Genre' => array());
foreach($this->request->data['Movie']['genre'] as $genre)
array_push($data_genre['Genre'], (int)$genre);
$data = array('Movie' => $data_movie, 'Genre' => $data_genre);
$this->Movie->create();
And save your data using
if ($this->Movie->saveAssociated($this->request->data) {
...
EDIT
Modify your form, change this
echo $this->Form->input('genre', array('type'=>'select', 'multiple'=>'checkbox', 'options'=> $genres));
to this
echo $this->Form->input('Genre', array('type'=>'select', 'multiple'=>'checkbox', 'options'=> $genres));