php - Modify $this->request->data in model CakePHP? -

how can modify $this->request->data model in cakephp. tried code in model user :

public function beforevalidate($options = array()) {     unset($this->request->data['user']['birthday']); } 

but return errors :

notice (8): indirect modification of overloaded property user::$request has no effect

warning (2): attempt modify property of non-object

if use (model user) :

public function beforevalidate($options = array()) {     unset($this->data[$this->alias]['birthday']); } 

it's ok, after validate, when tried print_r($this->request->data) in controller, see birthday field still exists in it.

anyone can give me solution this, different between $this->data , $this->request->data, !!

edit : cakephp version 2.6.7 - newest version.

$this->request->data cannot accessed within model. data accessible controller. when attempt save data model controller (e.g. $this->user->save($this->request->data))) setting user model's data attribute. in other words, happening:-

$this->user->data = $this->request->data; 

so in model's callback methods can access data being saved using $this->data , manipulate have found in beforevalidate():-

public function beforevalidate($options = array()) {     // unset 'birthday' data being saved     unset($this->data[$this->alias]['birthday']);     return parent::beforevalidate($options); } 

don't forget when using callback call parent method , ensure returns boolean. if doesn't return true data not saved!

if manipulate $this->data in model not affect $this->request->data can access model's data attribute within controller see changes. example, in controller after saving changes:-

// output user data debug($this->user->data); 

if want alter $this->request->data need within controller (presumably before save), not model:-

unset($this->request->data[$this->alias]['birthday']); 

just side note careful of unsetting data in model callback's everytime try save data (unless disable callback). unsetting birthdaywould result in never getting saved database.