Update tags module to notify modules when items related to a tag are

affected.  Practically speaking this means that we'll reindex items
when tags are added or removed from them.

API change:
  Remove item_related_updated_batch event.

Rationale:
  While this is an efficient event, it requires module developers to
  support two event APIs for staying up to date and increases the
  likelihood that they'll forget one and have data corruption.  Force
  them all through the slower but more reliable pipe, for now.  We
  can always try to improve efficiency by using the batch_start and
  batch_stop events.

1 files changed, 10 insertions, 3 deletions

diff --git a/modules/comment/helpers/comment_installer.php b/modules/comment/helpers/comment_installer.php
index f54913c3..edf2427c 100644
--- a/modules/comment/helpers/comment_installer.php
+++ b/modules/comment/helpers/comment_installer.php
@@ -52,8 +52,8 @@ class comment_installer {
   }
 
   static function upgrade($version) {
+    $db = Database::instance();
     if ($version == 1) {
-      $db = Database::instance();
       $db->query("ALTER TABLE {comments} CHANGE `state` `state` varchar(15) default 'unpublished'");
       module::set_version("comment", 2);
     }
@@ -61,9 +61,16 @@ class comment_installer {
 
   static function uninstall() {
     $db = Database::instance();
-    $sql = "SELECT `item_id` FROM {comments}";
-    module::event("item_related_update_batch", $sql);
 
+    // Notify listeners that we're deleting some data.  This is probably going to be very
+    // inefficient for large uninstalls, and we could make it better by doing things like passing
+    // a SQL fragment through so that the listeners could use subselects.  But by using a single,
+    // simple event API we lighten the load on module developers.
+    foreach (ORM::factory("item")
+             ->join("comments", "items.id", "comments.item_id")
+             ->find_all() as $item) {
+      module::event("item_related_update", $item);
+    }
     $db->query("DROP TABLE IF EXISTS {comments};");
   }
 }