设计模式(14)Command模式

abstract class Command
{
  protected $receiver;
  public function __construct($receiver){
    $this->receiver = $receiver;
  }
  public abstract function excute();
}
class Invoker
{
  protected $commands;
  public function setCommand(Command $command){
     $this->commands[] = $command;
  }
  public function excuteCommand(){
     foreach($this->commands as $command){
      $command->excute();
     }
  }
  public function removeCommand(Command $command){
    $key = array_search($command,$this->commands);
    if($key){
      unset($this->commands[$key]);
    }
  }
}
class ConcreteCommand1  extends Command
{
  public function excute(){
    $this->receiver->action1();
  }
}
class ConcreteCommand2  extends Command
{
  public function excute(){
    $this->receiver->action2();
  }
}
class Receiver1
{
  public function action1(){
    echo "do action1";
  }
}
class Receiver2
{
  public function action2(){
    echo "do action2";
  }
}

//测试代码
$receiver1 = new Receiver1();
$receiver2 = new Receiver2();
$command1 = new ConcreteCommand1($receiver1);
$command2 = new ConcreteCommand2($receiver2);
$invoker = new Invoker();
$invoker->setCommand($command1);
$invoker->setCommand($command2);
$invoker->excuteCommand();