cakephp not validating select field - validation

Question

I just downloaded a fresh copy of cakephp version 2.3.0 and I am trying to validate a select field of a form that I have just created:
echo $this->Form->input('province_id', array('empty' => '- select -', 'options' => $options));
echo $this->Form->input('username');
And the validation:
public $validate = array(
'username' => array(
'required' => array(
'rule' => array('notEmpty'),
'message' => 'A username is required'
)
),
'province_id' => array(
'rule' => 'notEmpty',
'message' => 'Select something'
)
);
The username field is being validated correctly, but the province_id is being ignored. What can it be?

Answer 1

You should write like this:
public $validate = array(
'username' => array(
'required' => array(
'rule' => array('notEmpty'),
'message' => 'A username is required'
)
),
'province_id' => array(
'required' => array(
'rule' => array('notEmpty'),
'message' => 'Select something'
)
)
);

Answer 2

It looks like your form helper declarations are fine.
My experience with Cake shows that the validation is screwy when you start to mix the syntax (one of your fields has a nested array, while the other doesn't). I am sure there is some rhyme or reason to what is going on, but I haven't really dived that deep and usually just do trial and error.
Try this:
public $validate = array(
'username' => array(
'rule' => 'notEmpty',
'required' => true,
'message' => 'A username is required'
),
'province_id' => array(
'rule' => 'notEmpty',
'required' => true,
'message' => 'Select something'
)
);

Answer 3

Better late then never, try this:
public $validate = array(
'username' => array(
'required' => array(
'rule' => array('notEmpty'),
'message' => 'A username is required'
)
),
'province_id' => array(
'required' => array(
'rule' => array('myOwnValidationRule'),
'message' => 'Select something'
)
)
);
function myOwnValidationRule($data)
{
if($data["province_id"] != 'empty')
{
return true;
}
}