Insert using class

/*
class Myclass {
       public $title = 'My Title';
       public $content = 'My Content';
       public $date = 'My Date';
}
*/

$object = new Myclass;
$this->db->insert('mytable', $object);

So like this i can do insert, but if i i want to  use input-post function with my variables
like this:  public $title = $this->input->post('some'); how i can do this?