MDL-61363 tag: add get_items_tags function

tag/classes/tag.php

@@ -638,19 +638,19 @@ protected function update_instance_ordering($instanceid, $ordering) {
     }
 
     /**
-     * Get the array of core_tag_tag objects associated with an item (instances).
+     * Get the array of core_tag_tag objects associated with a list of items.
      *
      * Use {@link core_tag_tag::get_item_tags_array()} if you wish to get the same data as simple array.
      *
      * @param string $component component responsible for tagging. For BC it can be empty but in this case the
      *               query will be slow because DB index will not be used.
      * @param string $itemtype type of the tagged item
-     * @param int $itemid
+     * @param int[] $itemids
      * @param int $standardonly wether to return only standard tags or any
      * @param int $tiuserid tag instance user id, only needed for tag areas with user tagging
      * @return core_tag_tag[] each object contains additional fields taginstanceid, taginstancecontextid and ordering
      */
-    public static function get_item_tags($component, $itemtype, $itemid, $standardonly = self::BOTH_STANDARD_AND_NOT,
+    public static function get_items_tags($component, $itemtype, $itemids, $standardonly = self::BOTH_STANDARD_AND_NOT,
             $tiuserid = 0) {
         global $DB;
 
@@ -659,34 +659,59 @@ public static function get_item_tags($component, $itemtype, $itemid, $standardon
             return array();
         }
 
+        if (empty($itemids)) {
+            return array();
+        }
+
         $standardonly = (int)$standardonly; // In case somebody passed bool.
 
+        list($idsql, $params) = $DB->get_in_or_equal($itemids, SQL_PARAMS_NAMED);
         // Note: if the fields in this query are changed, you need to do the same changes in core_tag_tag::get_correlated_tags().
         $sql = "SELECT ti.id AS taginstanceid, tg.id, tg.isstandard, tg.name, tg.rawname, tg.flag,
-                    tg.tagcollid, ti.ordering, ti.contextid AS taginstancecontextid
+                    tg.tagcollid, ti.ordering, ti.contextid AS taginstancecontextid, ti.itemid
                   FROM {tag_instance} ti
                   JOIN {tag} tg ON tg.id = ti.tagid
-                  WHERE ti.itemtype = :itemtype AND ti.itemid = :itemid ".
+                  WHERE ti.itemtype = :itemtype AND ti.itemid $idsql ".
                 ($component ? "AND ti.component = :component " : "").
                 ($tiuserid ? "AND ti.tiuserid = :tiuserid " : "").
                 (($standardonly == self::STANDARD_ONLY) ? "AND tg.isstandard = 1 " : "").
                 (($standardonly == self::NOT_STANDARD_ONLY) ? "AND tg.isstandard = 0 " : "").
                "ORDER BY ti.ordering ASC, ti.id";
 
-        $params = array();
         $params['itemtype'] = $itemtype;
-        $params['itemid'] = $itemid;
         $params['component'] = $component;
         $params['tiuserid'] = $tiuserid;
 
         $records = $DB->get_records_sql($sql, $params);
         $result = array();
+        foreach ($itemids as $itemid) {
+            $result[$itemid] = [];
+        }
         foreach ($records as $id => $record) {
-            $result[$id] = new static($record);
+            $result[$record->itemid][$id] = new static($record);
         }
         return $result;
     }
 
+    /**
+     * Get the array of core_tag_tag objects associated with an item (instances).
+     *
+     * Use {@link core_tag_tag::get_item_tags_array()} if you wish to get the same data as simple array.
+     *
+     * @param string $component component responsible for tagging. For BC it can be empty but in this case the
+     *               query will be slow because DB index will not be used.
+     * @param string $itemtype type of the tagged item
+     * @param int $itemid
+     * @param int $standardonly wether to return only standard tags or any
+     * @param int $tiuserid tag instance user id, only needed for tag areas with user tagging
+     * @return core_tag_tag[] each object contains additional fields taginstanceid, taginstancecontextid and ordering
+     */
+    public static function get_item_tags($component, $itemtype, $itemid, $standardonly = self::BOTH_STANDARD_AND_NOT,
+            $tiuserid = 0) {
+        $tagobjects = static::get_items_tags($component, $itemtype, [$itemid], $standardonly, $tiuserid);
+        return empty($tagobjects) ? [] : $tagobjects[$itemid];
+    }
+
     /**
      * Returns the list of display names of the tags that are associated with an item
      *
@@ -1158,7 +1183,7 @@ public function get_correlated_tags($keepduplicates = false) {
 
         // This is (and has to) return the same fields as the query in core_tag_tag::get_item_tags().
         $sql = "SELECT ti.id AS taginstanceid, tg.id, tg.isstandard, tg.name, tg.rawname, tg.flag,
-                tg.tagcollid, ti.ordering, ti.contextid AS taginstancecontextid
+                tg.tagcollid, ti.ordering, ti.contextid AS taginstancecontextid, ti.itemid
               FROM {tag} tg
         INNER JOIN {tag_instance} ti ON tg.id = ti.tagid
              WHERE tg.id $query AND tg.id <> ? AND tg.tagcollid = ?