PHP设计模式之中介者模式(Mediator Pattern)入门与应用案例详解

<?php
class CD {
 public $band = '';
 public $title = '';
 protected $_mediator;

 public function __construct(MusicContainerMediator $mediator = NULL) {
 $this->_mediator = $mediator;
 }

 public function save() {
 //具体实现待定
 var_dump($this);
 }

 public function changeBandName($bandname) {
 if ( ! is_null($this->_mediator)) {
  $this->_mediator->change($this, array("band" => $bandname));
 }
 $this->band = $bandname;
 $this->save();
 }
}
//MP3Archive类
class MP3Archive {
 protected $_mediator;

 public function __construct(MusicContainerMediator $mediator = NULL) {
 $this->_mediator = $mediator;
 }

 public function save() {
 //具体实现待定
 var_dump($this);
 }

 public function changeBandName($bandname) {
 if ( ! is_null($this->_mediator)) {
  $this->_mediator->change($this, array("band" => $bandname));
 }
 $this->band = $bandname;
 $this->save();
 }

}

 //中介者类
class MusicContainerMediator {
 protected $_containers = array();

 public function __construct() {
 $this->_containers[] = "CD";
 $this->_containers[] = "MP3Archive";
 }

 public function change($originalObject, $newValue) {
 $title = $originalObject->title;
 $band = $originalObject->band;
 foreach ($this->_containers as $container) {
  if ( ! ($originalObject instanceof $container)) {
  $object = new $container;
  $object->title = $title;
  $object->band = $band;
  foreach ($newValue as $key => $val) {
   $object->$key = $val;
  }
  $object->save();
  }
 }
 }
}

//测试实例
$titleFromDB = "Waste of a Rib";
$bandFromDB = "Never Again";
$mediator = new MusicContainerMediator();
$cd = new CD($mediator);
$cd->title = $titleFromDB;
$cd->band = $bandFromDB;
$cd->changeBandName("Maybe Once More");

//抽象同事类，家教
abstract class Tutor{
  protected $message;  //个人信息
  protected $mediator; //为家教服务的中介机构
  function __construct($message,Mediator $mediator){
    $this->message = $message;
    $this->mediator = $mediator;
  }
  //获取个人信息
  function getMessage(){
    return $this->message;
  }
  //找学生
  abstract function findStudent();
}
//具体同事类,大学生家教
class UndergraduateTutor extends Tutor{
  //家教类型
  public $type = "UndergraduateTutor";

  function __construct($message,Mediator $mediator){
     parent::__construct($message,$mediator);
  }
  //找学生,让中介机构代为寻找
  function findStudent(){
     $this->mediator->matchStudent($this);
  }
}
//具体同事类,高中生家教
class SeniorStudentTutor extends Tutor{
  //家教类型
  public $type = "SeniorStudentTutor";

  function __construct($message,Mediator $mediator){
     parent::__construct($message,$mediator);
  }
  //找学生,让中介机构代为寻找
  function findStudent(){
     $this->mediator->matchStudent($this);
  }
}
//具体同事类,初中生家教
class MiddleStudentTutor extends Tutor{
  //家教类型
  public $type = "MiddleStudentTutor";

  function __construct($message,Mediator $mediator){
     parent::__construct($message,$mediator);
  }
  //找学生,让中介机构代为寻找
  function findStudent(){
     $this->mediator->matchStudent($this);
  }
}

//抽象中介类
abstract class AbstractMediator{
  abstract function matchStudent(Tutor $tutor);
}
//具体中介类，为家教匹配合适的学生
class Mediator extends AbstractMediator{
  //定义其服务的所有家教，不在范围内的不服务
  private $serveObject = array("UndergraduateTutor","SeniorStudentTutor","MiddleStudentTutor");
  //匹配学生
  function matchStudent(Tutor $tutor){
     for($i=0;$i<count($this->serveObject);$i++){
       if($tutor->type == $this->serveObject[$i]){
         $message = $tutor->getMessage();
         echo "该家教个人信息为".print_r($message)."<br/>将为其匹配合适的学生";
         break;
       }
     }
     if($i>=count($this->serveObject)){
       echo "该家教不在我中介机构服务范围内";
     }
  }
}

//测试
$mediator = new Mediator();
$undergraduateTutor = new UndergraduateTutor(array("name"=>"张三","age"=>22),$mediator);
$undergraduateTutor->findStudent();
//结果：该家教个人信息为 Array ( [name] => 张三 [age] => 22 ),将为其匹配合适的学生