- Patch #651240 by fago, sun: allow modules to react to changes to an entity.

3 files changed, 42 insertions, 3 deletions

diff --git a/includes/common.inc b/includes/common.inc
index 56e276980..972fc2319 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -7334,6 +7334,28 @@ function entity_load($entity_type, $ids = FALSE, $conditions = array(), $reset =
 }
 
 /**
+ * Loads the unchanged, i.e. not modified, entity from the database.
+ *
+ * Unlike entity_load() this function ensures the entity is directly loaded from
+ * the database, thus bypassing any static cache. In particular, this function
+ * is useful to determine changes by comparing the entity being saved to the
+ * stored entity.
+ *
+ * @param $entity_type
+ *   The entity type to load, e.g. node or user.
+ * @param $id
+ *   The id of the entity to load.
+ *
+ * @return
+ *   The unchanged entity, or FALSE if the entity cannot be loaded.
+ */
+function entity_load_unchanged($entity_type, $id) {
+  entity_get_controller($entity_type)->resetCache(array($id));
+  $result = entity_get_controller($entity_type)->load(array($id));
+  return reset($result);
+}
+
+/**
  * Get the entity controller class for an entity type.
  */
 function entity_get_controller($entity_type) {
diff --git a/includes/entity.inc b/includes/entity.inc
index 1c3e7494e..5fb36e2dd 100644
--- a/includes/entity.inc
+++ b/includes/entity.inc
@@ -24,8 +24,12 @@ interface DrupalEntityControllerInterface {
 
   /**
    * Resets the internal, static entity cache.
+   *
+   * @param $ids
+   *   (optional) If specified, the cache is reset for the entities with the
+   *   given ids only.
    */
-  public function resetCache();
+  public function resetCache(array $ids = NULL);
 
   /**
    * Loads one or more entities.
@@ -139,8 +143,15 @@ class DrupalDefaultEntityController implements DrupalEntityControllerInterface {
   /**
    * Implements DrupalEntityControllerInterface::resetCache().
    */
-  public function resetCache() {
-    $this->entityCache = array();
+  public function resetCache(array $ids = NULL) {
+    if (isset($ids)) {
+      foreach ($ids as $id) {
+        unset($this->entityCache[$id]);
+      }
+    }
+    else {
+      $this->entityCache = array();
+    }
   }
 
   /**
diff --git a/includes/file.inc b/includes/file.inc
index 742c20e72..e8db63448 100644
--- a/includes/file.inc
+++ b/includes/file.inc
@@ -574,6 +574,11 @@ function file_save(stdClass $file) {
   $file->timestamp = REQUEST_TIME;
   $file->filesize = filesize($file->uri);
 
+  // Load the stored entity, if any.
+  if (!empty($file->fid) && !isset($file->original)) {
+    $file->original = entity_load_unchanged('file', $file->fid);
+  }
+
   if (empty($file->fid)) {
     drupal_write_record('file_managed', $file);
     // Inform modules about the newly added file.
@@ -587,6 +592,7 @@ function file_save(stdClass $file) {
     module_invoke_all('entity_update', $file, 'file');
   }
 
+  unset($file->original);
   return $file;
 }