Minor - format code, add validation

Author: jmontoyaa

main/inc/lib/AnnouncementManager.php

@@ -507,17 +507,21 @@ public static function getLastAnnouncementOrder($courseInfo)
             return 0;
         }
 
-        $table = Database::get_course_table(TABLE_ANNOUNCEMENT);
+        if (!isset($courseInfo['real_id'])) {
+            return false;
+        }
+
         $courseId = $courseInfo['real_id'];
+        $table = Database::get_course_table(TABLE_ANNOUNCEMENT);
         $sql = "SELECT MAX(display_order)
                 FROM $table
                 WHERE c_id = $courseId ";
-        $res_max = Database::query($sql);
+        $result = Database::query($sql);
 
         $order = 0;
-        if (Database::num_rows($res_max)) {
-            $row_max = Database::fetch_array($res_max);
-            $order = intval($row_max[0]) + 1;
+        if (Database::num_rows($result)) {
+            $row = Database::fetch_array($result);
+            $order = (int) $row[0] + 1;
         }
 
         return $order;
@@ -555,6 +559,10 @@ public static function add_announcement(
             return false;
         }
 
+        if (!isset($courseInfo['real_id'])) {
+            return false;
+        }
+
         $courseId = $courseInfo['real_id'];
         $tbl_announcement = Database::get_course_table(TABLE_ANNOUNCEMENT);