Adapt to centralised hook dispatcher in Drupal 9.4

Problem/Motivation

Core now has most of its hook invocations centralized to ModuleHandler, which allows this project to move invocations to a decorated dispatcher service rather than dispatching procedurally via .module files.

This is a partial proof of concept implementation which shows how the project can utilise these enhancements to core.

This will require that minimum Drupal version is 9.4. I suggest creating a new major or minor Drupal version of this project in order to responsibly go forward.

Invocations are moved from .module files to a ModuleHandler decorator, which offloads event creation to tag based factories. Ultimately most or all module files can be removed

Because of the scale of the changes required to satisfy this issue I've only gone ahead and implemented a small part of the project as an example. In case this is rejected. Also you may want to open separate issues to do address individual submodules work:

• Core submodule, partially implemented
• Field submodule, partially implemented
• User submodule, fully implemented
• Other submodules, fully implemented

With this work you can see multiple events can be dispatched per hook, events can be constructed in a special manner, events with return values are returned to the invoker, and alter arguments are passed by reference.

I personally don't use in this project, especially as I maintain Hux which is a good alternative to this project. During development of my contributions to the core issue useful to Hux, I identified that both of our projects could benefit.

The idea is the behaviour (input/output) does not change. There is only internal code optimizations and cleanups.

Remaining tasks

• Review viability
• Work out a plan for which version this should be implemented in
• Migrate remaining hook implementations from .module files to Factory services.
  • core_event_dispatcher_theme
  • field_event_dispatcher_field_formatter_settings_summary_alter
  • field_event_dispatcher_field_formatter_third_party_settings_form
  • field_event_dispatcher_field_widget_settings_summary_alter
  • field_event_dispatcher_field_widget_third_party_settings_form

User interface changes

API changes

New event factories
Internal tagged services
ModuleHandler decorator
Interface for event return values.
Interface + base for self event factory

Data model changes

Order of event invocation may change.