Drupal 9 - Field Group integration

d9_commerce_field_group.php

<?php

// Field group does not by default show on commerce relaed entities and those can be added using a hook

/**
 * Implements hook_field_group_content_element_keys_alter
 *
 * Add field groups to product and product variation.
 */
function fcl_commerce_field_group_content_element_keys_alter(&$keys) {
  if (!isset($keys['commerce_product_variation'])) {
    $keys['commerce_product_variation'] = 'product_variation';
  }

  if (!isset($keys['commerce_product'])) {
    $keys['commerce_product'] = 'product';
  }
}


// Commerce products do not show the field group but we can programmatically get those details

/**
 * Implements template_preprocess_commerce_product().
 */
function mytheme_preprocess_commerce_product(&$variables) {
  $product = $variables['elements']['#commerce_product'];
  $productvars = $variables['product'];
  if (is_object($product)) {
    $view_mode = $variables['elements']['#view_mode'];
    if ($view_mode == 'full') {
      $variables['field_group_fields'] = _getFieldGroupFields($variables);
    }
  }


/*
 * Get the field group fields from the field group
 */
function _getFieldGroupFields(&$variables) {
  $techspecfields = [];
  // Get the list of fields from the product variation using EntityViewDisplay
  $variation =_getProductVariation($variables);
  if (!empty($variation)) {
    $display_options = EntityViewDisplay::collectRenderDisplay($variation, 'full');
    $field_group = $display_options->getThirdPartySetting('field_group', 'fieldgroup_one');
    foreach ($field_group['children'] as $item) {
      $fld = $variation->{$item};
      /** @var \Drupal\field\Entity\FieldConfig $fld_def */
      $fld_def = $fld->getFieldDefinition();
      $lbl = $fld_def->getLabel();
      $fieldgroup_one[$item] = $lbl;
    }
  }
  // Code for illustration only - should do more processing of the array to make it usable by the Twig template.
  retuen $fieldgroup_one
}