How to do a PHP hook system?

Question

How do you impliment a hook system in a PHP application to change the code before or after it executes. How would the basic architecture of a hookloader class be for a PHP

Answer 1

Here's another solution:

Creating a hook

Run this wherever you want to create a hook:

x_do_action('header_scripts');

---

Attach a function to the hook

Then attach a function to the above by doing:

x_add_action('header_scripts','my_function_attach_header_scripts');

function my_function_attach_header_scripts($values) {

   /* add my scripts here */

}

---

Global variable to store all hooks/events

Add this to the top of your main PHP functions file, or equivalent

$x_events = array();
global $x_events;

---

Base functions

function x_do_action($hook, $value = NULL) {
    global $x_events;

    if (isset($x_events[$hook])) {

        foreach($x_events[$hook] as $function) {

            if (function_exists($function)) { call_user_func($function, $value); }

        }
    }

}

function x_add_action($hook, $func, $val = NULL) {
    global $x_events;
    $x_events[$hook][] = $func;

}