From 4445858df2fd31780d86e9b38a39ef612ec7c00f Mon Sep 17 00:00:00 2001
From: Jordan Dukart <jordan@discoverygarden.ca>
Date: Fri, 24 Jul 2015 11:00:37 -0300
Subject: [PATCH] Allow modules to modify which object is being loaded.

---
 includes/metadata.inc |  4 ++++
 islandora.api.php     | 22 ++++++++++++++++++++++
 islandora.module      |  2 ++
 3 files changed, 28 insertions(+)

diff --git a/includes/metadata.inc b/includes/metadata.inc
index bf59b830..9a75cd05 100644
--- a/includes/metadata.inc
+++ b/includes/metadata.inc
@@ -20,6 +20,8 @@ function islandora_retrieve_metadata_markup(AbstractObject $object, $print = FAL
   $viewer = variable_get('islandora_metadata_display', 'dublin_core');
   $markup = '';
   if (isset($viewers[$viewer]['metadata callback'])) {
+    $hooks = islandora_build_hook_list(ISLANDORA_METADATA_OBJECT_ALTER, $object->models);
+    drupal_alter($hooks, $object);
     $markup = call_user_func($viewers[$viewer]['metadata callback'], $object, $print);
     // The callback doesn't have any markup provided for this particular object,
     // default back to the dublin_core display.
@@ -44,6 +46,8 @@ function islandora_retrieve_description_markup(AbstractObject $object) {
   $viewer = variable_get('islandora_metadata_display', 'dublin_core');
   $markup = '';
   if (isset($viewers[$viewer]['description callback'])) {
+    $hooks = islandora_build_hook_list(ISLANDORA_METADATA_OBJECT_DESCRIPTION_ALTER, $object->models);
+    drupal_alter($hooks, $object);
     $markup = call_user_func($viewers[$viewer]['description callback'], $object);
     // The callback doesn't have any markup provided for this particular object,
     // default back to the dublin_core display.
diff --git a/islandora.api.php b/islandora.api.php
index e7026923..dda2d20b 100644
--- a/islandora.api.php
+++ b/islandora.api.php
@@ -794,3 +794,25 @@ function hook_islandora_metadata_display_info() {
     ),
   );
 }
+
+/**
+ * Allows modifications to the object whose metadata is being rendered.
+ *
+ * @param AbstractObject $object
+ *   An AbstractObject representing an object within Fedora.
+ */
+function hook_islandora_metadata_object_alter(AbstractObject &$object) {
+  $this_other_object = islandora_object_load('awild:indirectionappears');
+  $object = $this_other_object;
+}
+
+/**
+ * Allows modifications to the object whose metadata is being rendered.
+ *
+ * @param AbstractObject $object
+ *   An AbstractObject representing an object within Fedora.
+ */
+function hook_islandora_metadata_object_description_alter(AbstractObject &$object) {
+  $this_other_object = islandora_object_load('awild:indirectionappears');
+  $object = $this_other_object;
+}
diff --git a/islandora.module b/islandora.module
index 10d6060f..884e534c 100644
--- a/islandora.module
+++ b/islandora.module
@@ -49,6 +49,8 @@ define('ISLANDORA_POST_INGEST_HOOK', 'islandora_ingest_post_ingest');
 define('ISLANDORA_PRE_PURGE_OBJECT_HOOK', 'islandora_pre_purge_object');
 define('ISLANDORA_POST_PURGE_OBJECT_HOOK', 'islandora_post_purge_object');
 define('ISLANDORA_UPDATE_RELATED_OBJECTS_PROPERTIES_HOOK', 'islandora_update_related_objects_properties');
+define('ISLANDORA_METADATA_OBJECT_ALTER', 'islandora_metadata_object');
+define('ISLANDORA_METADATA_OBJECT_DESCRIPTION_ALTER', 'islandora_metadata_object_description');
 
 // @todo Add Documentation.
 define('ISLANDORA_OBJECT_INGESTED_HOOK', 'islandora_object_ingested');