How to conditionally assign a role?

darkdim → closed merge request !1

darkdim → reopened merge request !1

darkdim → closed merge request !1

darkdim → closed merge request !2

darkdim → changed the visibility of the branch 3380038-how-to-conditionally to hidden.

Oooh very interesting. Could you describe how the event can be intercepted/used?

Yes, sure.
1. Create a module
2. You need to describe the service as an event subscriber
3. Create an EventSubscriber directory in the src folder
4. Create the subscriber class itself

There is a book with a code, at the address you can see events https://selwynpolit.github.io/d9book/events

services:
  my_module.roles_subscriber:
    class: Drupal\my_module\EventSubscriber\ClassSubscriber
    arguments: []
    tags:
      - { name: event_subscriber }

<?php

namespace Drupal\my_module\EventSubscriber;

use Drupal\registration_role\Event\SelectRoleEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

class ClassSubscriber implements EventSubscriberInterface {

  public static function getSubscribedEvents() {
    $events[SelectRoleEvent::SELECT_ROLE_EVENT][] = ['registrationRole', 0];
    return $events;
  }

  public function registrationRole(SelectRoleEvent $event) {
    $user = $event->getUser();
    ... logic ...
  }

}