Planet CakePHP

Validating fields based on the values of other fields can be hard to understand when you are new to CakePHP. A simple example of this can be comparing two values, like e-mail addresses or passwords. It is actually pretty easy because in the custom validation method you have access to $this->data.

So here is how it goes. This will also invalidate the value compared with, so you will have to call this validation rule only once.

public function compare($value, $options = array(), $rule = array()) {
	$valid = current($value) == $this->data[$this->alias][$options[0]];
	if (!$valid) {
		$this->invalidate($options[0], $rule['message']);
	}
	return $valid;
}

In $validate it will look like this:

public $validate = array(
	'email' => array(
		/*
		'email' => array(
			'rule' => 'email',
			'message' => 'This must be a valid e-mail address.',
			'last' => true
		),
		*/
		'compare' => array(
			'rule' => array('compare', array('email_confirm')),
			'message' => "These e-mail addresses don't match."
		),
		/*
		'maxlength' => array(
			'rule' => array('maxLength', 100),
			'message' => "The e-mail address is too long."
		),
		'isunique' => array(
			'rule' => 'isUnique',
			'message' => 'This e-mail address is already in our database.'
		)
		*/
	)
);