CakePHP: How to set variables with multiple level dependancies - php

Question

In my controller I want to set a variable(A) which has a one to many relationship with another model(B) which has a HABTM (has and belongs to many) relationship with ANOTHER model(C).
Currently when I set the variable in the controller I can access the model(B) in the view, but not ITS dependancies (model C):
//A's controller...
public function admin_view($id = NULL) {
$A = $this->A->findById($id);
$this->set('A', $A);
}
Here's what I see if I dump the variable in the view:
//A's admin_view.ctp...
//debug($A);
array(
'A' => array(
'id' => '1',
'name' => 'Name',
'created' => '2013-04-04 15:25:54',
'modified' => '2013-04-04 15:25:54'
),
'B' => array(
(int) 0 => array(
'id' => '1',
'created' => '0000-00-00 00:00:00',
'modified' => '2013-04-05 10:31:42'
),
(int) 1 => array(
'id' => '13',
'created' => '0000-00-00 00:00:00',
'modified' => '2013-04-05 10:31:42'
Is there a way to set the variable such the each "B" will have it's respective Cs included?

Answer 1

http://book.cakephp.org/2.0/en/core-libraries/behaviors/containable.html
// In your model
var $actsAs = array('Containable');
// In your controller
public function admin_view($id = NULL) {
$this->A->contain(array('B' => array('C')));
$A = $this->A->findById($id);
$this->set('A', $A);
}
That should give you what you need, setting recursive to 2 is the easy way out, but you'll get redundant data if you have other associations.

Answer 2

Well then, explaining $recursive and Containable behavior:
Recursive is a value between -1 to 2, and basically it tells the model "I want to fetch this record AND all records associated with it" if it's set to 2. If it's -1, then with find or read you only get that model data.
Containable let's you specify which models/fields-of-other-models you want to fetch (they have to have an association, though).
I've repeated many times I'm not a fan of $recursive != -1 because I feel it doesn't let you control what data you retrieve and when to do it. I recommend you use
class AppModel extends Model {
public $actsAs = array('Containable');
public $recursive = -1;
//etc
}
in the AppMdel so everything isn't recursive and containable by default (it isn't necessary for the query to work, though). Then, regarding your question, the find query should be like
$A = $this->A->find('first', array('conditions'=>array('id'=>$id),
'contain'=>array('B-model'=>array('C-model'))));