PHP中使用事件派发机制实现解耦

class EventManager
{
    private $events = [];

    public function registerEvent($eventName)
    {
        $this->events[$eventName] = [];
    }

    public function attach($eventName, $handler)
    {
        $this->events[$eventName][] = $handler;
    }

    public function detach($eventName, $handler)
    {
        foreach ($this->events[$eventName] as $key => $value) {
            if ($value == $handler) {
                unset($this->events[$eventName][$key]);
                break;
            }
        }
    }

    public function trigger($eventName, $data)
    {
        foreach ($this->events[$eventName] as $handler) {
            call_user_func($handler, $data);
        }
    }
}

class ModuleA
{
    public function handleEventA($data)
    {
        echo "Module A handles Event A: " . $data . "
";
    }
}

class ModuleB
{
    public function handleEventB($data)
    {
        echo "Module B handles Event B: " . $data . "
";
    }
}

$eventManager = new EventManager();

$moduleA = new ModuleA();
$moduleB = new ModuleB();

$eventManager->registerEvent('EventA');
$eventManager->attach('EventA', [$moduleA, 'handleEventA']);

$eventManager->registerEvent('EventB');
$eventManager->attach('EventB', [$moduleB, 'handleEventB']);

$data = "Hello, World!";

$eventManager->trigger('EventA', $data);
$eventManager->trigger('EventB', $data);

Module A handles Event A: Hello, World!
Module B handles Event B: Hello, World!