Using a base subclass

gistfile1.php

<?php

class Base extends lithium\data\Model { 
	
	public function save($entity, $data = null, array $options = array()) { 
		if ($data) { 
			$entity->set($data); 
		} 
		if (!$entity->exists()) { 
			$entity->created = new MongoDate(); 
		} 
		$entity->updated = new MongoDate(); 
	
		return parent::save($entity, null, $options); 
	}
}

class Posts extends Base { 
	//...
}