README

Hooks is a small library that provided hookable actions and filters, similar to WordPress. This can be used in any PHP 7.4+ project and is a simple way of implementing plugin capabilities in your applications by exposing hookable actions and filters to plugin-code.

The Hook class provides a simple interface to registering functions to call under specific hook names, sorted by priority. A hook's list of functions can then be executed with optional parameters, or used as an accumulator for an initial value.

While the Hook class itself can be used to create, register and execute hooks, you can also use the global hook_* functions to shortcut these operations.

Menu Example

A menu might include a default list of items, then this list may be passed to a filter hook to allow plugins to modify or append to the list.

Application Usage

$menu = [
    'Plugins' => [
        new MenuItem('Plugin Manager', '/plugins/index')
    ]
];
$menuItems = hook_filter('main_menu', $menu);

// Add menu items to UI...

Plugin Usage

A plugin can then modify the list by receiving it and adding its own items through a callback added to the same hook.

hook_add('main_menu', function(array $menu)
{
    $menu['Plugins'][] = new MenuItem('My Plugin', '/my-plugin/');
    return $menu;
});

Executing Actions with Hooks

To create, add a function to a hook then execute it, use the following alternatives:

$hook = \YetAnother\Hook::get('do_stuff');
$hook->add(function($param)
{
    print($param);
});
$hook->run('Hello, world!');

// "Hello, world!" is printed

hook_add('do_stuff', fn($param) => print($param));
hook_run('do_stuff', 'Hello, world!');

Filtering with Hooks

By registering callbacks on a hook used as a filter, you can receive input and pass results to the next function in the filter.

hook_add('accumulate', fn($initial, $parameter) => $initial + $parameter);
hook_add('accumulate', fn($initial, $parameter) => $initial * $parameter);

$result = hook_filter('accumulate', 5, 7);

// $result = 54 ((5 + 7) * 7)

hook_add('menu', function(array $menu)
{
    $menu[] = 'World';
    return $menu;
});

$menu = hook_filter('menu', [ 'Hello' ]);

// $menu = [ 'Hello', 'World' ]