/**
* Signs user up.
*
* @return User|null the saved model or null if saving fails
*/
public function signup()
{
if ($this->validate()) {
$user = new User();
$user->username = $this->username;
$user->email = $this->email;
$user->setPassword($this->password);
$user->generateAuthKey();
$user->save();
return $user;
}
return null;
}