Combining validation syntax in CakePHP - validation

Question

Say I have a fairly typical, by-the-docs validation array and I want to keep those rules and add a specific validation rule for 8+ other fields.
Original $validate:
var $validate = array(
'name' => array(
'notEmpty'=> array(
'rule' => 'notEmpty',
'message' => 'Name can not be blank.'
),
'allowedCharacters'=> array(
'rule' => '|^[a-zA-Z ]*$|',
'message' => 'Name can only be letters.'
),
'minLength'=> array(
'rule' => array('minLength', 3),
'message' => 'Name must be at least 3 characters long.'
),
'maxLength'=> array(
'rule' => array('maxLength', 255),
'message' => 'Name can not be longer that 255 characters.'
)
),
'email' => array(
'email' => array(
'rule' => 'email',
'message' => 'Please provide a valid email address.'
),
'isUnique' => array(
'rule' => 'isUnique',
'message' => 'This E-mail used by another user.'
)
)
);
I can add the following rule to the validation array, but I do not want to have to repeat it 8 times.
////fragment of array
'field1' => array(
'greaterThanField' => array(
'rule' => array('greaterThanField', 'age'),
'message' => 'This field cannot be greater than age'
)
)
////
function greaterThanField( $field=array(), $compare_field=null ){
foreach( $field as $key => $value ){
$v1 = $value;
$v2 = $this->data[$this->name][ $compare_field ];
if($v1 > $v2) {
return false;
} else {
continue;
}
}
return true;
}
And I want to add to this an array of field names that will all be evaluated using the same rule and message. I tried creating a variable in the model and then running code on the beforeValidate function, but beforeValidate doesn't seem to have access to the compareFields variable
var $compareFields = array('field1', 'field2', 'field3', 'field4', 'field5', 'field6', 'field7', 'field8');
function beforeValidate(){
foreach ($compareFields as $field) {
$validate[$field] = array(
'rule'=> array('greaterThanField', 'age' ),
'message'=>'Cannot exceed delivery age',
);
}
}
What is the proper way to achieve this?

Answer 1

If you're using 2.2 then check this.
If you're using an older version and (if I understood correctly your question) you are too lazy to add the same validation rule to multiple fields, then I would add them dynamically in the constructor of your model. I don't like that solution though, I would stick to the convention.