Disabling a Behavior from inside its setup() method

Sometime you write a nice Behavior, that will automate a lot of stuff that almost all your models will need. But, unfortunatly, a couple of models won't need it. Actually, attaching it to them will even break your code.

So what do you do? Do you resort to manually fill the $actsAs variable of each model, except for the two lonely loosers, or defining the $actsAs of your main AppModel really seems more appaling?

Lazyness to the rescue

If, like me, you prefer writing less code, you'd probably go with the AppModel approach. All you have to do is define a setup() method in your Behavior and check if it is applied to the right or wrong type of model. Fortunatly for us, the $model is passed as first argument.

Once you've identified the faulty models, you just have to disable the behavior for them. The BehaviorCollection that comes bundle into $model->Behaviors has a nice couple of enable/disable methods. Unfortunatly, they won't work from inside the setup() method because the Behavior is not yet correctly instanciated.

What you can do, however, is to hack inside the BehaviorCollection to update the inner _disabled key to add your own Behavior to the list.

function setup(&$model, $config = array()) {
  [...]
  if ($faultyModel) {
    $model->Behaviors->_disabled[] = 'MyBehavior';
  }
}

This is more than a bit hacky, I have to admit that. But it does the trick. Enjoy.