PHP设计模式之命令模式示例详解

class Invoker
{
 public $command;
 
 public function __construct($command)
 {
  $this->command = $command;
 }

 public function exec()
 {
  $this->command->execute();
 }
}

abstract class Command
{
 protected $receiver;

 public function __construct(Receiver $receiver)
 {
  $this->receiver = $receiver;
 }

 abstract public function execute();
}

class ConcreteCommand extends Command
{
 public function execute()
 {
  $this->receiver->action();
 }
}

class Receiver
{
 public $name;

 public function __construct($name)
 {
  $this->name = $name;
 }

 public function action()
 {
  echo $this->name . '命令执行了！', PHP_EOL;
 }
}

// 准备执行者
$receiverA = new Receiver('A');

// 准备命令
$command = new ConcreteCommand($receiverA);

// 请求者
$invoker = new Invoker($command);
$invoker->exec();

<?php

class Invoker
{
 private $command = [];

 public function setCommand(Command $command)
 {
  $this->command[] = $command;
 }

 public function exec()
 {
  if(count($this->command) > 0){
   foreach ($this->command as $command) {
    $command->execute();
   }
  }
 }

 public function undo()
 {
  if(count($this->command) > 0){
   foreach ($this->command as $command) {
    $command->undo();
   }
  }
 }
}

abstract class Command
{
 protected $receiver;
 protected $state;
 protected $name;

 public function __construct(Receiver $receiver, $name)
 {
  $this->receiver = $receiver;
  $this->name = $name;
 }

 abstract public function execute();
}

class ConcreteCommand extends Command
{
 public function execute()
 {
  if (!$this->state || $this->state == 2) {
   $this->receiver->action();
   $this->state = 1;
  } else {
   echo $this->name . '命令正在执行，无法再次执行了！', PHP_EOL;
  }

 }
 
 public function undo()
 {
  if ($this->state == 1) {
   $this->receiver->undo();
   $this->state = 2;
  } else {
   echo $this->name . '命令未执行，无法撤销了！', PHP_EOL;
  }
 }
}

class Receiver
{
 public $name;
 public function __construct($name)
 {
  $this->name = $name;
 }
 public function action()
 {
  echo $this->name . '命令执行了！', PHP_EOL;
 }
 public function undo()
 {
  echo $this->name . '命令撤销了！', PHP_EOL;
 }
}

// 准备执行者
$receiverA = new Receiver('A');
$receiverB = new Receiver('B');
$receiverC = new Receiver('C');

// 准备命令
$commandOne = new ConcreteCommand($receiverA, 'A');
$commandTwo = new ConcreteCommand($receiverA, 'B');
$commandThree = new ConcreteCommand($receiverA, 'C');

// 请求者
$invoker = new Invoker();
$invoker->setCommand($commandOne);
$invoker->setCommand($commandTwo);
$invoker->setCommand($commandThree);
$invoker->exec();
$invoker->undo();

// 新加一个单独的执行者，只执行一个命令
$invokerA = new Invoker();
$invokerA->setCommand($commandOne);
$invokerA->exec();

// 命令A已经执行了，再次执行全部的命令执行者，A命令的state判断无法生效
$invoker->exec();

<?php

class SendMsg
{
 private $command = [];

 public function setCommand(Command $command)
 {
  $this->command[] = $command;
 }
 
 public function send($msg)
 {
  foreach ($this->command as $command) {
   $command->execute($msg);
  }
 }
}

abstract class Command
{
 protected $receiver = [];

 public function setReceiver($receiver)
 {
  $this->receiver[] = $receiver;
 }

 abstract public function execute($msg);
}

class SendAliYun extends Command
{
 public function execute($msg)
 {
  foreach ($this->receiver as $receiver) {
   $receiver->action($msg);
  }
 }
}

class SendJiGuang extends Command
{
 public function execute($msg)
 {
  foreach ($this->receiver as $receiver) {
   $receiver->action($msg);
  }
 }
}

class SendAliYunMsg
{
 public function action($msg)
 {
  echo '【阿X云短信】发送：' . $msg, PHP_EOL;
 }
}

class SendAliYunPush
{
 public function action($msg)
 {
  echo '【阿X云推送】发送：' . $msg, PHP_EOL;
 }
}

class SendJiGuangMsg
{
 public function action($msg)
 {
  echo '【极X短信】发送：' . $msg, PHP_EOL;
 }
}

class SendJiGuangPush
{
 public function action($msg)
 {
  echo '【极X推送】发送：' . $msg, PHP_EOL;
 }
}

$aliMsg = new SendAliYunMsg();
$aliPush = new SendAliYunPush();
$jgMsg = new SendJiGuangMsg();
$jgPush = new SendJiGuangPush();

$sendAliYun = new SendAliYun();
$sendAliYun->setReceiver($aliMsg);
$sendAliYun->setReceiver($aliPush);

$sendJiGuang = new SendJiGuang();
$sendAliYun->setReceiver($jgMsg);
$sendAliYun->setReceiver($jgPush);

$sendMsg = new SendMsg();
$sendMsg->setCommand($sendAliYun);
$sendMsg->setCommand($sendJiGuang);

$sendMsg->send('这次要搞个大活动，快来注册吧！！');