How do I split my HABTM tags? - has-and-belongs-to-many

Question

I want to take a field in the add form of the Post, explode it at the spaces, and save each word as a Tag, which HasAndBelongsToMany Post. So, for each unrecognized tag, it will create a new one, but if the Tag already exists, it will only create a new reference in the posts_tags tables. I've tried using saveAll, saveAssociated, and few foreach hacks, and I am not exactly sure where it went wrong, but I cannot figure out how to save the associate data. Any sort of outline of how to get the tag data from the form to the database would be appreciated.
//in model
public function parseTags($data) {
$str = $data['Tag'][0]['title'];
$tags = explode('',$str);
for ($i=0; $i<count($tags); $i++) {
$data['Tag'][$i]['title'] = $tags[$i];
}
return $data;
}
//in view
echo $this->Form->input('Tag.0.title',array('label'=>'Tags'));
//in controller
public function add() {
if ($this->request->is('post')) {
$this->Question->create();
$this->request->data['Question']['user_id'] = $this->Auth->user('id');
$this->request->data = $this->Question->parseTags($this->request->data);
if ($this->Question->saveAll($this->request->data)) {
$this->Session->setFlash(__('The question has been saved'), 'default', array('class' => 'success'));
$this->redirect(array('action' => 'index'));
} else {
$this->Session->setFlash(__('The question could not be saved. Please, try again.'));
}
}
$users = $this->Question->User->find('list');
$this->set(compact('users'));
}

Answer 1

You must first check if Tag saved before or not, if not saved, You can save it. So before you save your model ,all of your tags is saved before.
something like this:
/* $tag_list is exploded tags*/
foreach ($tag_list as $tag) {
$res = $this->Tag->find('first', array('conditions' => array('Tag.name' => $tag)));
if ($res != array()) {
$tag_info[] = $res['Tag']['id'];
} else {
$this->Tag->create();
$this->Tag->save(array('Tag.name' => $tag));
$tag_info[] = sprintf($this->Tag->getLastInsertID());
}
}
$this->model->data['Tag']['Tag'] = $tag_info;