From a2dc13192f9462bc4a05f336d9384ba1eb7c6b0b Mon Sep 17 00:00:00 2001
From: Charles Severance <csev@umich.edu>
Date: Mon, 10 Jun 2024 09:06:33 -0400
Subject: [PATCH] Add the lti.gradeChangeNotify post message

---
 src/Core/Result.php |  3 +++
 src/UI/Output.php   | 24 +++++++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/Core/Result.php b/src/Core/Result.php
index 69c9e492..631c67d4 100644
--- a/src/Core/Result.php
+++ b/src/Core/Result.php
@@ -389,6 +389,9 @@ public function gradeSend($grade, $row=false, &$debug_log=false, $extra=false) {
                 if ( is_array($debug_log) )  $debug_log[] = $msg;
                 error_log($msg);
             }
+
+            // Send notification
+            $this->session_put('lti.gradeChangeNotify', true);
         } else {
             $msg = 'Grade failure '.$grade.' id='.$USER->id.' via '.$GradeSendTransport;
             if ( is_array($debug_log) )  $debug_log[] = $msg;
diff --git a/src/UI/Output.php b/src/UI/Output.php
index d8f99c5f..0a19aebd 100644
--- a/src/UI/Output.php
+++ b/src/UI/Output.php
@@ -616,12 +616,26 @@ public static function handleHeartBeat($cookie)
     }
 
     function footerEnd() {
-        $end = "\n</div></body>\n</html>\n";
-        if ( $this->buffer ) {
-            return $end;
-        } else {
-            echo($end);
+        ob_start();
+
+        if ( $this->session_get('lti.gradeChangeNotify') ) {
+?>
+<script>
+            if ( typeof lti_gradeChangeNotify === 'function' ) {
+                console.debug('Tsugi sending lti.gradeChangeNotify');
+                lti_gradeChangeNotify();
+            }
+</script>
+<?php
+            $this->session_forget('lti.gradeChangeNotify');
         }
+
+        echo("\n</div></body>\n</html>\n");
+
+        $ob_output = ob_get_contents();
+        ob_end_clean();
+        if ( $this->buffer ) return $ob_output;
+        echo($ob_output);
     }
 
     function footer() {