--- /dev/null
+/**
+ * Implements hook_ENTITY_TYPE_view().
+ */
+function {{ machine_name }}_ENTITY_TYPE_view(array &$build, \Drupal\Core\Entity\EntityInterface $entity, \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display, $view_mode) {
+ // Only do the extra work if the component is configured to be displayed.
+ // This assumes a 'mymodule_addition' extra field has been defined for the
+ // entity bundle in hook_entity_extra_field_info().
+ if ($display->getComponent('mymodule_addition')) {
+ $build['mymodule_addition'] = [
+ '#markup' => mymodule_addition($entity),
+ '#theme' => 'mymodule_my_additional_field',
+ ];
+ }
+}