This is the standard approach to identify a vs. an existing user being updated.
Inside presave , always call $user->isNew() to ensure your code only runs during initial registration rather than every time a profile is updated.
For cleaner, decoupled code, consider Symfony Event Subscribers if you are using the Hook Event Dispatcher module. drupal-8-user-register-hook
[Solved] How to hook into Commerce after payment complete - Drupal
Best for modifying data (e.g., adding a default role) before it hits the database. Runs after the user is created. This is the standard approach to identify a vs
If you need to stop registration based on custom business logic (e.g., checking an external blacklist), use a custom validation handler via hook_form_alter .
Use this to add custom fields or validation logic (e.g., matching a secondary database). 💻 Code Example: hook_user_presave If you need to stop registration based on
Do you need help on the registration form, or are you looking to redirect users after they sign up?