MDL-41942 course: Allow course listings to work with caches disabled

diff --git a/lib/coursecatlib.php b/lib/coursecatlib.php
index 5348112..520840e 100644 (file)
--- a/lib/coursecatlib.php
+++ b/lib/coursecatlib.php
@@ -572,12 +572,6 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
         if ($rv !== false) {
             return $rv;
         }
-        // We did not find the entry in cache but it also can mean that tree is not built.
-        // The keys 0 and 'countall' must always be present if tree is built.
-        if ($id !== 0 && $id !== 'countall' && $coursecattreecache->has('countall')) {
-            // Tree was built, it means the non-existing $id was requested.
-            return false;
-        }
         // Re-build the tree.
         $sql = "SELECT cc.id, cc.parent, cc.visible
                 FROM {course_categories} cc
@@ -619,7 +613,8 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
         if (array_key_exists($id, $all)) {
             return $all[$id];
         }
-        return false;
+        // Requested non-existing category.
+        return array();
     }
 
     /**
@@ -1187,8 +1182,13 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
         $coursecatcache = cache::make('core', 'coursecat');
         $cntcachekey = 'scnt-'. serialize($search);
         if (($cnt = $coursecatcache->get($cntcachekey)) === false) {
-            self::search_courses($search, $options);
-            $cnt = $coursecatcache->get($cntcachekey);
+            // Cached value not found. Retrieve ALL courses and return their count.
+            unset($options['offset']);
+            unset($options['limit']);
+            unset($options['summary']);
+            unset($options['coursecontacts']);
+            $courses = self::search_courses($search, $options);
+            $cnt = count($courses);
         }
         return $cnt;
     }
@@ -1311,8 +1311,13 @@ class coursecat implements renderable, cacheable_object, IteratorAggregate {
         $cntcachekey = 'lcnt-'. $this->id. '-'. (!empty($options['recursive']) ? 'r' : '');
         $coursecatcache = cache::make('core', 'coursecat');
         if (($cnt = $coursecatcache->get($cntcachekey)) === false) {
-            $this->get_courses($options);
-            $cnt = $coursecatcache->get($cntcachekey);
+            // Cached value not found. Retrieve ALL courses and return their count.
+            unset($options['offset']);
+            unset($options['limit']);
+            unset($options['summary']);
+            unset($options['coursecontacts']);
+            $courses = $this->get_courses($options);
+            $cnt = count($courses);
         }
         return $cnt;
     }