defer derivatives api

includes/derivatives.inc

@@ -4,6 +4,9 @@
  * Defines functions used when constructing derivatives.
  */
 
+// Relations.
+define('ISLANDORA_DEFER_DERIVATIVES_FLAG', 'deferDerivatives');
+
 /**
  * Decides which derivative function to call and runs it.
  *
@@ -245,3 +248,39 @@ function islandora_filter_derivatives($hooks, $options, AbstractObject $object)
   $hooks = array_filter($hooks, $filter_function);
   return $hooks;
 }
+
+/**
+ * Set the defer derivatives flag on an object.
+ */
+function islandora_set_defer_derivatives_flag(AbstractObject $object) {
+  $object->relationships->add(
+    ISLANDORA_RELS_EXT_URI,
+    ISLANDORA_DEFER_DERIVATIVES_FLAG,
+    'true',
+    RELS_TYPE_PLAIN_LITERAL
+  );
+}
+
+/**
+ * Get the defer derivatives flag on an object.
+ */
+function islandora_get_defer_derivatives_flag(AbstractObject $object) {
+  return $object->relationships->get(
+    ISLANDORA_RELS_EXT_URI,
+    ISLANDORA_DEFER_DERIVATIVES_FLAG,
+    'true',
+    RELS_TYPE_PLAIN_LITERAL
+  );
+}
+
+/**
+ * Remove the defer derivatives flag on an object.
+ */
+function islandora_remove_defer_derivatives_flag(AbstractObject $object) {
+  $object->relationships->remove(
+    ISLANDORA_RELS_EXT_URI,
+    ISLANDORA_DEFER_DERIVATIVES_FLAG,
+    'true',
+    RELS_TYPE_PLAIN_LITERAL
+  );
+}

includes/regenerate_derivatives.form.inc

@@ -95,6 +95,7 @@ function islandora_regenerate_object_derivatives_form_submit(array $form, array
  */
 function islandora_regenerate_object_derivatives_batch(AbstractObject $object) {
   module_load_include('inc', 'islandora', 'includes/derivatives');
+  islandora_remove_defer_derivatives_flag($object);
   return array(
     'title' => t('Regenerating all derivatives for @label', array('@label' => $object->label)),
     'operations' => islandora_do_batch_derivatives($object, array('force' => TRUE)),
@@ -117,6 +118,7 @@ function islandora_regenerate_object_derivatives_batch(AbstractObject $object) {
  */
 function islandora_regenerate_datastream_derivative_batch(AbstractDatastream $datastream) {
   module_load_include('inc', 'islandora', 'includes/derivatives');
+  islandora_remove_defer_derivatives_flag($object);
   return array(
     'title' => t('Regenerating derivatives for the @dsid datastream', array('@dsid' => $datastream->id)),
     'operations' => islandora_do_batch_derivatives($datastream->parent, array(

islandora.module

@@ -1719,6 +1719,10 @@ function islandora_islandora_basic_collection_get_query_filters() {
  */
 function islandora_islandora_object_ingested(AbstractObject $object) {
   module_load_include('inc', 'islandora', 'includes/derivatives');
+  // Defer derivatives if necessary.
+  if (islandora_get_defer_derivatives_flag($object)) {
+    return;
+  }
   islandora_run_derivatives($object, NULL);
 }
 
@@ -1730,6 +1734,10 @@ function islandora_islandora_object_ingested(AbstractObject $object) {
  */
 function islandora_islandora_datastream_ingested(AbstractObject $object, AbstractDatastream $datastream) {
   module_load_include('inc', 'islandora', 'includes/derivatives');
+  // Defer derivatives if necessary.
+  if (islandora_get_defer_derivatives_flag($object)) {
+    return;
+  }
   islandora_run_derivatives($object, $datastream->id);
 }