abselect.module

<?php

/**
 * @file
 * Authored By Select module file.
 */

use Drupal\Core\Entity\EntityTypeInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\abselect\Plugin\Field\FieldWidget\AuthoredBySelect;
use Drupal\user\Entity\User;

/**
 * Implements hook_entity_base_field_info_alter().
 */
function abselect_entity_base_field_info_alter(&$fields, EntityTypeInterface $entity_type) {
  // Sets the "Authored by" field of nodes to use our custom form widget.
  if ($entity_type->id() == 'node') {
    $roles = AuthoredBySelect::getUserRoles(TRUE);
    $fields['uid']->setDisplayOptions('form', [
      'type' => 'authored_by_select',
      'weight' => 5,
      'settings' => [
        'delegation_roles' => $roles,
        'authoring_roles' => $roles,
        'disabled_visibility' => 'readonly',
      ],
    ]);
  }
}

/**
 * Implements hook_form_node_form_alter().
 */
function abselect_form_node_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  $storage = $form_state->getStorage();
  $uid_field = $storage['form_display']->getComponent('uid');
  if (!empty($uid_field) && $uid_field['type'] == 'authored_by_select') {
    if (isset($form['uid']['widget'][0]['target_id']['#assignedAuthor'])) {
      // Change the name of the author displayed in the meta information area if
      // current users will not be able to set themselves as author. This won't
      // change the functionality of the form, is just a way to avoid confusion.
      $author = User::load($form['uid']['widget'][0]['target_id']['#assignedAuthor'])
        ->getDisplayName();
    }
    elseif (isset($form['uid']['widget'][0]['target_id']['#default_value'][0])) {
      // Pick the selected value in the form element.
      $author = User::load($form['uid']['widget'][0]['target_id']['#default_value'][0])
        ->getDisplayName();
    }
    else {
      // If no value was defined, it means that the only author available is the
      // anonymous user.
      $author = \Drupal::config('user.settings')->get('anonymous');
    }
    $form['meta']['author']['#markup'] = '<span class="authored-by-name">' . $author . '</span>';
  }
}