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Callbacks

Callbacks allow the programmer to hook into the life cycle of an ActiveRecord\Model object. You can control the state of your object by declaring certain methods to be called before or after methods are invoked on your object inside of ActiveRecord.

Before callbacks

If a before_* callback returns false, execution of any other callbacks after the offending callback will not be fired and the model will not be saved/deleted.

before_save: called before a model is saved before_create: called before a NEW model is to be inserted into the database before_update: called before an existing model has been saved before_validation: called before running validators before_validation_on_create: called before validation on a NEW model being inserted before_validation_on_update: same as above except for an existing model being saved before_destroy: called before a model has been deleted

class Order extends ActiveRecord\Model {
  static $before_create = array('apply_tax'); # new records only
  static $before_save = array('upcase_state'); # new OR updated records

  public function apply_tax() {
    if ($this->state == 'VA')
      $tax = 0.045;
    elseif ($this->state == 'CA')
      $tax = 0.10;
    else
      $tax = 0.02;
 
    $this->tax = $this->price * $tax;
  }
 
  public function upcase_state() {
    $this->state = strtoupper($this->state);
  }
}
 
$attributes = array('item_name' => 'Honda Civic',
  'price' => 7000.00, 'state' => 'va');
 
$order = Order::create($attributes);
echo $order->tax; # => 315.00
echo $order->state; # => VA

# somehow our order changed states!
$order->state = 'nc';
$order->save();
echo $order->state; # => NC

After callbacks

after_save: called after a model is saved after_create: called after a NEW model has been inserted into the database after_update: called after an existing model has been saved after_validation: called after running validators after_validation_on_create: called after validation on a NEW model being inserted after_validation_on_update: same as above except for an existing model being saved after_destroy: called after a model has been deleted

class User extends ActiveRecord\Model {
  static $after_create = array('send_new_user_email'); # new records only
  static $after_destroy = array('delete_all_related_data');
 
  public function delete_all_related_data() {
    # delete all associated objects
  }
 
  public function send_new_user_email() {
    mail($this->email, "Thanks for signing up, {$this->name}!", "The subject");
  }
}
 
$attributes = array('name' => 'Jax', 'email' => 'nonya@nonya.com');
$user = User::create($attributes);
# an e-mail was just sent...

$user->delete();
# everything associated with this user was just deleted