What are the best way to allow plugins for a PHP application

Question

I want to create something that people can extend by using a plugin interface.

How does one go about writing 'hooks' into their code so that plugins can attach to specific events?

Thank You!

Answer 1

Hii,

• Here is an approach I have  used, it's an attempt to copy from Qt signals/slots mechanism, a kind of Observer pattern. 
• Objects can emit signals. Every signal has an ID in the system - it's composed by sender's id + object name Every signal can be binded to the receivers, which simply is a "callable" .
• You use a bus class to pass the signals to anybody interested in receiving them When something happens, you "send" a signal.

 Below is and example implementation

    <?php

class SignalsHandler {


    /**
     * hash of senders/signals to slots
     *
     * @var array
     */
    private static $connections = array();


    /**
     * current sender
     *
     * @var class|object
     */
    private static $sender;


    /**
     * connects an object/signal with a slot
     *
     * @param class|object $sender
     * @param string $signal
     * @param callable $slot
     */
    public static function connect($sender, $signal, $slot) {
        if (is_object($sender)) {
            self::$connections[spl_object_hash($sender)][$signal][] = $slot;
        }
        else {
            self::$connections[md5($sender)][$signal][] = $slot;
        }
    }