Why Drupal module developers should be excited about object-oriented hooks

It's not super-often that a Drupal core change record stops me in my tracks, but recently, one did exactly that.

With so much of Drupal core written using modern, object-oriented PHP, there was still one place where we needed to use plain-old PHP functions: hook implementations. Drupal hooks have been with us since before I started with Drupal (over 18 years ago,) and I had long hoped that with the advent of "modern" Drupal (Drupal 8+,) eventually hooks would be converted over to Symfony events. 

Much to my surprise, a recent change record for Drupal 11.x-dev (to be included in Drupal 11.1) has virtually all hooks (there are some exceptions) now being available as "object oriented hook implementations." 😀

The change record that put that smile on my face:
 

Support for object oriented hook implementations using autowired services

The short version

Classes can now be written that include methods that can act as hook implementation via a PHP attribute.

Click on the change record link above for a code sample. 

Just as cool - there's backward compatibility built-in so that you can start writing OO hooks today. 

The longer version

Go read the entire change record. 👍🏼

Why is this such a good thing?

• First, less plain-old PHP functions + more classes = more modern PHP.
• Secondly, these hook classes are services, which makes them more performant than plain-old PHP functions.
• Thirdly, you can organize related hooks in their own classes.

Where can I see this in action?

Together with students from our current Professional Module Development class, we put together a quick module that:

1. Implements hook_user_login() using this new technique to display a welcome message to the user. 
2. Includes the backwards compatibility stuff so that it works in Drupal 10.3+
3. Is written with both Drupal coding standards and PHPStan level 6 compliance. 

Feel free to download or clone the no_more_hooks module from GitHub and check it out on your Drupal 10.3 or 11 site!