PHPで使うGoFパターン ひとり Advent Calendar - メディエーター

<?php
//
// MediatorBase
//
abstract class MediatorBase {
  private   $_Colleagues  = array ();

  public function learn ( $obj ) {
    if ( !( $obj instanceof ColleagueBase ) )
      throw new Exception ( 'そんなオブジェクト無理だもん!' );

    if ( $this->getObject ( $obj->getID() )  )
      throw new Exception ( 'ダブってるもん!' .  $obj->getID() );
    $obj->setMediator ( $this );
    $this->_Colleagues[] = $obj;
  }

  public function getObject ( $id ) {
    $arr = array_filter ( $this->_Colleagues, function ( $obj ) use ( $id ) {
      return $id == $obj->getID();
    });
    $key = array_keys ( $arr );
    return $arr[$key[0]];
  }
}

//
// 操作される側 Colleague の 雛形
//
abstract class ColleagueBase {
  private   $_ID = null;
  protected $_Mediator = null;
  private $_Inbox = array ();
  public function setID ( $id ) {
    if ( !$id ) throw new Exception ( 'IDが無いもん!' );
    $this->_ID = $id;
  }

  public function getID () {
    if ( !$this->_ID )
      throw new Exception ( 'IDが設定されてないもん!' );
    return get_class ( $this ) . "|" . $this->_ID;
  }

  public function setMediator ( $obj ) {
    if ( !( $obj instanceof MediatorBase ) )
      throw new Exception ( 'そんなオブジェクト無理だもん!' );
    $this->_Mediator = $obj;
  }

  public function sendMessage ( $to_id, $msg ) {
    $this->_Mediator->sendMessage ( $this->getID(), $to_id, $msg );
  }

  public function recieveMessage ( $from_id, $msg ) {
    $this->_Inbox[] = array (
      'from'    => $from_id,
      'message' => $msg,
      'date_time' => date ( 'Y/m/d H:i:s' ),
    );
  }

  public function getInbox () {
    return $this->_Inbox;
  }

}

//
// 操作される側 Colleague の 実クラス
//
class User extends ColleagueBase {
  public function __construct ( $id ) {
    $this->setID( $id );
  }
}

//
// 操作される側 Colleague の 実クラス その2
//
class Company extends ColleagueBase {
  public function __construct ( $id ) {
    $this->setID ( $id );
  }
}

//
// 実 Mediator
//
class PostMan extends MediatorBase {
  public function sendMessage ( $from_id, $to_id, $msg ) {
    if ( !( $to = $this->getObject ( $to_id ) ) )
      throw new Exception ( 'そんなID無いもん' . $to_id );
    $to->recieveMessage ( $from_id, $msg );
  }
}

$pm = new PostMan();
$larry =  new User ( 'Larry' );
$gates  = new User ( 'Gates' );
$jobs   = new User ( 'Jobs' );
$ms     = new Company ( 'M$' ) ;
$apple  = new Company ( 'Apple' );

$pm->learn ( $larry );
$pm->learn ( $gates );
$pm->learn ( $jobs );
$pm->learn ( $ms );
$pm->learn ( $apple );

$larry->sendMessage ( 'User|Gates', 'ヽ(゜▽、゜)ノ' );
$larry->sendMessage ( 'User|Jobs', '＼(^o^)／' );
$larry->sendMessage ( 'Company|Apple', '(^^)' );

print "== " . $apple->getID() . " == \n";
var_dump ( $apple->getInbox() );

print "== " . $jobs->getID() . " == \n";
var_dump ( $jobs->getInbox() );

print "== " . $gates->getID() . " == \n";
var_dump ( $gates->getInbox() );