unl_cas.module

<?php

use Drupal\user\UserInterface;
use Drupal\user\Entity\User;

/**
 * Implements hook_install().
 */
function unl_cas_install() {
  \Drupal::configFactory()->getEditable('user.settings')
    ->set('register', UserInterface::REGISTER_ADMINISTRATORS_ONLY)
    ->save(TRUE);
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function unl_cas_form_user_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
  // Disable and hide things that shouldn't be altered when using the CAS module.
  $form['account']['mail']['#disabled'] = TRUE;
  $form['account']['cas_enabled']['#disabled'] = TRUE;
  $form['account']['cas_username']['#disabled'] = TRUE;
  $form['account']['name']['#disabled'] = TRUE;

  $form['account']['pass']['#access'] = FALSE;
  $form['account']['status']['#access'] = FALSE;

  // We want anyone who can access this form to be able to edit a user's roles.
  // We do this here because we don't want Site Admin to have the full
  // 'Administer roles and permissions' permission.
  $form['account']['roles']['#access'] = TRUE;

  // If user isn't an Administrator, they can't assign 'coder' role.
  $form['account']['roles']['coder']['#disabled'] = TRUE;
  // Limit 'Cancel account' ability to only Super Administrators.
  $form['actions']['delete']['#access'] = FALSE;

  if (User::load(\Drupal::currentUser()->id())->hasRole('administrator')) {
    $form['account']['roles']['coder']['#disabled'] = FALSE;
  }
  if (User::load(\Drupal::currentUser()->id())->hasRole('super_administrator')) {
    $form['account']['roles']['coder']['#disabled'] = FALSE;
    $form['actions']['delete']['#access'] = TRUE;
  }

  // Always disable the Administrator roles. They should be managed via Drush.
  $form['account']['roles']['administrator']['#disabled'] = TRUE;
  $form['account']['roles']['super_administrator']['#disabled'] = TRUE;
}

/**
 * Implements hook_menu_links_discovered_alter().
 */
function unl_cas_menu_links_discovered_alter(&$links) {
  unset($links['admin_toolbar_tools.extra_links:user.admin_create']);
  unset($links['cas.bulk_add_users']);
}