How to get newly created user id in user_presave hook?

Question

Following is my .module file code

/**
 * Implements hook_user_presave().
 */

function cost_sheet_user_presave($account) {
    $source_userid = $account->id();
    \Drupal::messenger()->addMessage(t($source_userid));

}

This is giving me uid for already existing users when edited but not printing any value when a new user is created. How to get uid of newly created user in drupal 8 user presave hook?

Answer 1

You can't get the user ID in hook_user_presave() for a new user because the ID isn't assigned until the user is saved.

So how do I run code that uses the user ID when saving a user, regardless of whether the user is new or has been edited?

Refactor your code that does something with the user ID into a function, doStuffWithUserID().

function mymodule_user_presave($account) {
  if (!$account->isNew()) {
    doStuffWithUserID();
  }
}

function mymodule_user_insert($account) {
  // The new account has been saved, so we have an ID.
  doStuffWithUserID();
}

Answer 2

The only hooks called after an entity is saved in the database are hook_ENTITY_TYPE_update() for updated entities, and hook_ENTITY_TYPE_insert() for new entities. Once the entity is stored in the database, its ID will have a value.

Unfortunately, Drupal core doesn't use any hook_ENTITY_TYPE_postsave() which would make sense as it uses hook_ENTITY_TYPE_presave().

This means that your module should implement cost_sheet_user_update() and cost_sheet_user_insert().

Keep in mind that EntityStorageBase::doPostSave() invokes either one or the other of those hooks. Their code doesn't need to check whether the entity is new.

// Allow code to run after saving.
$entity->postSave($this, $update);
$this->invokeHook($update ? 'update' : 'insert', $entity);