中介者模式

<?php
 
// 中介者接口
interface Mediator
{
    public function notify(string $event): void;
}
 
// 具体中介者类
class ConcreteMediator implements Mediator
{
    private $component1;
    private $component2;
 
    public function setComponent1(Component1 $component1): void
    {
        $this->component1 = $component1;
        $this->component1->setMediator($this);
    }
 
    public function setComponent2(Component2 $component2): void
    {
        $this->component2 = $component2;
        $this->component2->setMediator($this);
    }
 
    public function notify(string $event): void
    {
        if ($event === "A") {
            echo "中介者响应 A 事件，并触发以下操作：\n";
            $this->component2->doC();
        } elseif ($event === "B") {
            echo "中介者响应 B 事件，并触发以下操作：\n";
            $this->component1->doA();
        }
    }
}
 
// 基础组件类
class BaseComponent
{
    protected $mediator;
 
    public function setMediator(Mediator $mediator): void
    {
        $this->mediator = $mediator;
    }
}
 
// 具体组件类 1
class Component1 extends BaseComponent
{
    public function doA(): void
    {
        echo "组件 1 执行 A\n";
        $this->mediator->notify("A");
    }
 
    public function doB(): void
    {
        echo "组件 1 执行 B\n";
        $this->mediator->notify("B");
    }
}
 
// 具体组件类 2
class Component2 extends BaseComponent
{
    public function doC(): void
    {
        echo "组件 2 执行 C\n";
    }
 
    public function doD(): void
    {
        echo "组件 2 执行 D\n";
    }
}
 
// 客户端代码
$component1 = new Component1();
$component2 = new Component2();
$mediator = new ConcreteMediator();
$mediator->setComponent1($component1);
$mediator->setComponent2($component2);
 
echo "客户端触发组件 1 的 A 操作：\n";
$component1->doA();
 
echo "\n客户端触发组件 1 的 B 操作：\n";
$component1->doB();