一天一个设计模式（13）——命令模式

<?php
class Bulb {
    public function turnOn() {
        echo ‘Bulb has turned on‘;
    }

    public function turnOff() {
        echo ‘Bulb has turned off‘;
    }
}

interface Order {
    public function execute();
    public function undo();
    public function redo();
}

class TurnOn implements Order {
    private $_bulb;
    public function __construct(Bulb $bulb) {
        $this->_bulb = $bulb;
    }

    public function execute() {
        $this->_bulb->turnOn();
    }

    public function undo() {
        $this->_bulb->turnOff();
    }

    public function redo() {
        $this->_bulb->turnOn();
    }
}

class TurnOff implements Order {
    private $_bulb;

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

    public function execute() {
        $this->_bulb->turnOff();
    }

    public function undo() {
        $this->_bulb->turnOn();
    }

    public function redo() {
        $this->_bulb->turnOff();
    }
}

class Control {
    public function submit($order) {
        $order->execute();
    }
}

$bulb = new Bulb();
$turnOn = new TurnOn($bulb);
$turnOff = new TurnOff($bulb);

$control = new Control();
$control->submit($turnOn);
echo PHP_EOL;
$control->submit($turnOff);