user_delete_reassign-8.x-1.x-dev/user_delete_reassign.module

<?php

/**
 * @file
 * Contains user_delete_reassign.module.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\user\Entity\User;

/**
 * Implements hook_help().
 */
function user_delete_reassign_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the user_delete_reassign module.
    case 'help.page.user_delete_reassign':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Alters the user deletion form allowing users to reassign their content to some other existing users.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_user_cancel_methods_alter().
 */
function user_delete_reassign_user_cancel_methods_alter(&$methods) {
  $account = \Drupal::currentUser();

  $user_delete_reassign = [
    'title' => t('Disable the account and make its content belong to another user.'),
    'description' => t('All the content will be assigned to another user.'),
    'access' => $account
      ->hasPermission('access delete and reassign user deletion'),
  ];

  $delete_title_with_extra_warning = [
    '#type' => 'html_tag',
    '#tag' => 'span',
    '#attributes' => ['class' => 'color-warning'],
    '#value' => $methods['user_cancel_delete']['title'] . ' ' . t('USE WITH CARE, THIS COULD LEAD TO MISSING CONTENTS!'),
  ];
  $methods['user_cancel_delete']['title'] = \Drupal::service('renderer')->render($delete_title_with_extra_warning);

  $methods = array_slice($methods, 0, 2, TRUE) +
    ['user_delete_reassign' => $user_delete_reassign] +
    array_slice($methods, 2, NULL, TRUE);
}

/**
 * Implements hook_form_alter().
 */
function user_delete_reassign_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  $allowed_roles = \Drupal::config('user_delete_reassign.settings')->get('role_filter');
  $forms = ["user_multiple_cancel_confirm", "user_cancel_form"];
  if (in_array($form_id, $forms)) {
    $form['user_cancel_reassign_to'] = [
      '#type' => 'entity_autocomplete',
      '#title' => t("User to assign this user's content to"),
      '#target_type' => 'user',
      '#selection_handler' => 'default:user_advanced',
      '#selection_settings' => [
        'include_anonymous' => FALSE,
        'exclude_users' => $form_id == 'user_cancel_form' ? [$form['uid']['#value']] : array_keys($form['account']['names']['#items']),
        'filter' => [
          'type' => 'role',
          'role' => $allowed_roles,
        ],
      ],
      '#states' => [
        'visible' => [
          '[name="user_cancel_method"]' => [
            'value' => 'user_delete_reassign',
          ],
        ],
        'required' => [
          '[name="user_cancel_method"]' => [
            'value' => 'user_delete_reassign',
          ],
        ],
      ],
      // Validation is done in static::validateConfigurationForm().
      '#size' => '60',
      '#maxlength' => '60',
      "#description" => t("Select a user to reassign content to."),
    ];
    // Rearrange things in the form: user_cancel_reassign_to must be in between
    // other fields.
    $form['account']['#weight'] = 0;
    $form['user_cancel_method']['#weight'] = 10;
    $form['user_cancel_reassign_to']['#weight'] = 20;
    $form['user_cancel_confirm']['#weight'] = 30;
    $form['description']['#weight'] = 40;
    // Make this option default.
    $form['user_cancel_method']['#default_value'] = "user_delete_reassign";
  }
}

/**
 * Implements hook_user_cancel().
 */
function user_delete_reassign_user_cancel($edit, $account, $method) {
  switch ($method) {
    case 'user_delete_reassign':
      if (!isset($edit['user_cancel_reassign_to'])) {
        $message = t('Please select a user to reassign the content to.');
        \Drupal::messenger()->addError($message, TRUE);
        return FALSE;
      }
      elseif ($account->id() === $edit['user_cancel_reassign_to']) {
        $message = t('Can not reassign content to same user.');
        \Drupal::messenger()->addError($message, TRUE);
        return FALSE;
      }
      $new_user = User::load($edit['user_cancel_reassign_to']);
      Drupal::moduleHandler()->loadInclude('node', 'inc', 'node.admin');
      $nodes = \Drupal::entityQuery('node')
        ->condition('uid', $account->id())
        ->execute();
      node_mass_update($nodes, ['uid' => $new_user->id()], NULL, TRUE);
      // Assign old revisions to the same user.
      \Drupal::database()->update('node_field_revision')
        ->fields(['uid' => $new_user->id()])
        ->condition('uid', $account->id())
        ->execute();
      $message = t('@count nodes have been assigned to @user.', [
          '@count' => count($nodes),
          '@user' => $new_user->getDisplayName(),
      ]);
      \Drupal::messenger()->addStatus($message, TRUE);
      break;
  }
}