<?php

/**
 * LoginForm base class
 *
 * @author Markus Lanthaler <markus@silverstripe.com>
 */


/**
 * Abstract base class for a login form
 *
 * This class is used as a base class for the different log-in forms like
 * {@link MemberLoginForm} or {@link OpenIDLoginForm}.
 *
 * @author Markus Lanthaler <markus@silverstripe.com>
 */
abstract class LoginForm extends Form {

  /**
   * Authenticator class to use with this login form
   *
   * Set this variable to the authenticator class to use with this login
   * form.
   *
   * @var string
   */
  protected $authenticator_class;


  /**
   * Get the authenticator class
   *
   * @return Authenticator Returns the authenticator class for this login
   *                       form.
   */
  public function getAuthenticator() {
    if(!class_exists($this->authenticator_class) ||
       !is_subclass_of($this->authenticator_class, 'Authenticator')) {
      user_error('The form uses an invalid authenticator class!',
                 E_USER_ERROR);
      return;
    }

    return new $this->authenticator_class;
  }
}


?>