try to integrate display suite extrafields

extrafield_views_integration.module

@@ -49,6 +49,7 @@ function _extrafield_views_integration_get_all_entity_types() {
       }
     }
   }
+  $test = ds_get_fields('node');
   return $entity_types;
 }
 
@@ -63,16 +64,26 @@ function _extrafield_views_integration_get_all_entity_types() {
  *   Reference for the extra fields array.
  */
 function _extrafield_views_integration_get_extra_fields_for_entity_type($entity_type, $bundles, &$extra_fields) {
+  $callback = '';
   foreach ($bundles as $bundle) {
     $temp_fields = field_info_extra_fields($entity_type, $bundle, 'display');
     if (!empty($temp_fields)) {
       foreach ($temp_fields as $field_name => $temp_field) {
         if (isset($temp_field['callback']) && function_exists($temp_field['callback'])) {
+          $callback = $temp_field['callback'];
+        }
+        else {
+          $callback = 'extrafield_' . $entity_type . '_' . $bundle . '_' . $field_name;
+          if(!function_exists($callback)) {
+            $callback = '';
+          }
+        }
+        if(!empty($callback)) {
           $extra_fields[$field_name] = array(
             'entity_type' => $entity_type,
             'label' => $temp_field['label'],
             'description' => $temp_field['description'],
-            'callback' => $temp_field['callback'],
+            'callback' => $callback,
           );
         }
       }