Global belongsTo conditions defined in model not being applied (CakePHP v2.4.2)

Question

Why are my global belongsTo conditions defined within a model not being applied?

I'm using CakePHP v2.4.2.

In model Order.php:

public $belongsTo = array(
...,
'Agent' => array(
    'className' => 'Party',
    'foreignKey' => 'agent_id',
    'conditions' => array(...)
),
...

In controller OrdersController.php:

$agents = $this->Order->Agent->find('list');

In rendered view the following SQL statement is being applied:

SELECT `Agent`.`id`, `Agent`.`name` FROM `zeevracht2`.`parties` AS `Agent` WHERE 1 = 1;

I tried different conditions, but even a simple string containing true isn't being applied (while adding this condition to PartiesController.php within a $this->Order->Agent->find(); works fine:

$agents = $this->Order->Agent->find('list', array(
    'conditions' => array('true')
));

leads to:

SELECT `Agent`.`id`, `Agent`.`name` FROM `zeevracht2`.`parties` AS `Agent` WHERE true;

Answer 1

After collaborating on IRC I found the answer on my own question.

It seems that conditions in the belongsTo condition of a model is only applied to the JOIN when querying an Order.

I was trying to filter Party on specific roles, e.g. Agent, which is an alias of a Party with a role as agent. So the association should be conditioned with a role set as agent. Ideally, this would automatically condition any $this->Order->Agent->find() calls. But unfortunately, this is not possible due to a technical issue which is being addressed in the development of version 3 of CakePHP.

The solution is to have two types of conditions on the association: one for the JOIN and one for the association itself.

Why one for the JOIN? E.g. when a Post belongs to User, but only post.validated should be displayed.