php “PHP Bits：Visual Debt”中的代码https://laracasts.com/series/php-bits/episodes/1

Posted 2021-05-05

<?php

$event = new Event;

$event->listen('subscribed', function () {
    var_dump('handling it');
});

$event->listen('subscribed', function () {
    var_dump('handling it again');
});

$event->fire('subscribed');

<?php

interface EventInterface {
    public function listen(string $name, callable $handler) : void;
    public function fire(string $name) : bool;
}

<?php

final class Event implements EventInterface
{
    protected $events = [];

    public function listen(string $name, callable $handler) : void
    {
        $this->events[$name][] = $handler;
    }

    public function fire(string $name) : bool
    {
        if (! array_key_exists($name, $this->events)) {
            return false;
        }

        foreach ($this->events[$name] as $event) {
            $event();
        }

        return true;
    }
}