global defer derivatives setting

includes/admin.form.inc

@@ -61,6 +61,13 @@ function islandora_repository_admin(array $form, array &$form_state) {
           '#description' => t('HTTP caching can reduce network traffic, by allowing clients to used cached copies.'),
           '#default_value' => variable_get('islandora_use_datastream_cache_headers', TRUE),
         ),
+        'islandora_defer_derivataves_on_ingest' => array(
+          '#type' => 'checkbox',
+          '#title' => t('Defer derivative generation during ingest'),
+          '#description' => t('Prevent derivatives from running during ingest,
+            useful if derivatives are to be created by an external service.'),
+          '#default_value' => variable_get('islandora_defer_derivataves_on_ingest', FALSE),
+        ),
       ),
       'islandora_namespace' => array(
         '#type' => 'fieldset',

islandora.install

@@ -46,6 +46,7 @@ function islandora_uninstall() {
   // Add new variables to clean up.
   $variables = array(
     'islandora_ds_replace_exclude_enforced',
+    'islandora_defer_derivataves_on_ingest',
   );
   array_walk($variables, 'variable_del');
 }

islandora.module

@@ -1962,3 +1962,14 @@ function islandora_menu_local_tasks_alter(&$data, $router_item, $root_path) {
     }
   }
 }
+
+/**
+ * Implements hook_islandora_object_alter().
+ */
+function islandora_islandora_object_alter(AbstractObject $object, array &$context) {
+  // Prevent derivative creation during ingest if var is set.
+  if ($context['action'] == 'ingest' && variable_get('islandora_defer_derivataves_on_ingest', FALSE)) {
+    module_load_include('inc', 'islandora', 'includes/derivatives');
+    islandora_set_defer_derivatives_flag($object);
+  }
+}