Hook inside class

Question

I would like know if it's possible to use hook inside a class and inside .module file.

By example :

modulename.module

<?php
use Drupal\xenforo\Xenforo\XenAPI;
use Drupal\Core\Entity\EntityInterface;
Class XenforoBridgeIntegration {
    // use Drupal 8 hook here and can use OrientedObject inside
}

I have try, but hook don't work if it's inside a class ?

Answer 1

No, it's not possible.

Hooks are functions that exist in the global namespace. Class/instance methods cannot be used to implement them.

If you take a look at the very simple ModuleHandler::invoke method, you'll see this in action:

public function invoke($module, $hook, array $args = array()) {
  if (!$this->implementsHook($module, $hook)) {
    return;
  }
  $function = $module . '_' . $hook;
  return call_user_func_array($function, $args);
}

As you can see, you must have a function called MODULENAME_HOOKNAME available in the global namespace, no consideration is given to classes or namespace resolution.

You can (and probably should) hand off whatever processing you're doing inside the hook to a specific class, but the hook itself will need to be implemented in procedural style.