dcco-8.x-3.x-dev/modules/dcco_session/dcco_session.module

<?php

/**
 * @file
 * Main module file.
 */

use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_module_implements_alter().
 */
function dcco_session_module_implements_alter(&$implementations, $hook) {
  // If this module exists for form alters, move it's execution to the end of
  // the call stack.
  if ($hook == 'form_alter' && isset($implementations['dcco_session'])) {
    $group = $implementations['dcco_session'];
    unset($implementations['dcco_session']);
    $implementations['dcco_session'] = $group;
  }
}

/**
 * Implements hook_form_alter().
 */
function dcco_session_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  if ($form_id == 'node_session_edit_form' || $form_id == 'node_session_add_form') {
    // If we have a scheduling group, hide access to those fields except for
    // admins.
    if (isset($form['#fieldgroups']['group_session_schedule'])) {
      $schedule_fields = $form['#fieldgroups']['group_session_schedule'];
      $current_user = \Drupal::currentUser();

      if ($current_user->hasPermission('manage dcco session schedule')) {
        foreach ($schedule_fields->children as $field_name) {
          $form[$field_name]['#access'] = FALSE;
        }
      }
    }
  }
}