MDL-36712: Assignment - Do not always send feedback available emails …

…when grade is created

The entry in the assign_grades table contains grades feedback and other settings such as locked.
Only send the student an email about new feedback if it is actually grades or feedback that
has been added. This is done by using another state for the mailed flag (2) which means "unset".

mod/assign/feedback/file/importziplib.php

@@ -266,7 +266,7 @@ public function import_zip_files($assignment, $fileplugin) {
                     $fileplugin->update_file_count($grade);
 
                     // Update the last modified time on the grade which will trigger student notifications.
-                    $assignment->update_grade($grade);
+                    $assignment->notify_grade_modified($grade);
                 }
             }
         }

mod/assign/feedback/file/locallib.php

@@ -403,6 +403,7 @@ public function view_batch_upload_files($users) {
             // Now copy each of these files to the users feedback file area.
             foreach ($users as $userid) {
                 $grade = $this->assignment->get_user_grade($userid, true);
+                $this->assignment->notify_grade_modified($grade);
 
                 $this->copy_area_files($fs,
                                        $this->assignment->get_context()->id,

mod/assign/feedback/offline/locallib.php

@@ -157,6 +157,7 @@ public function process_import_grades($draftid, $importid, $ignoremodified) {
                 $grade->grade = $record->grade;
                 $grade->grader = $USER->id;
                 if ($this->assignment->update_grade($grade)) {
+                    $this->assignment->notify_grade_modified($grade);
                     $this->assignment->add_to_log('grade submission', $this->assignment->format_grade_for_log($grade));
                     $updatecount += 1;
                 }
@@ -178,6 +179,7 @@ public function process_import_grades($draftid, $importid, $ignoremodified) {
                     if ($newvalue != $oldvalue) {
                         $updatecount += 1;
                         $grade = $this->assignment->get_user_grade($record->user->id, true);
+                        $this->assignment->notify_grade_modified($grade);
                         if ($plugin->set_editor_text($field, $newvalue, $grade->id)) {
                             $logdesc = get_string('feedbackupdate', 'assignfeedback_offline',
                                                   array('field'=>$description,

mod/assign/locallib.php

@@ -1476,6 +1476,23 @@ static function cron() {
         return true;
     }
 
+    /**
+     * Mark in the database that this grade record should have an update notification sent by cron.
+     *
+     * @param stdClass $grade a grade record keyed on id
+     * @return bool true for success
+     */
+    public function notify_grade_modified($grade) {
+        global $DB;
+
+        $grade->timemodified = time();
+        if ($grade->mailed != 1) {
+            $grade->mailed = 0;
+        }
+
+        return $DB->update_record('assign_grades', $grade);
+    }
+
     /**
      * Update a grade in the grade table for the assignment and in the gradebook
      *
@@ -2175,6 +2192,10 @@ public function get_user_grade($userid, $create) {
             $grade->grade = -1;
             $grade->grader = $USER->id;
             $grade->extensionduedate = 0;
+
+            // The mailed flag can be one of 3 values: 0 is unsent, 1 is sent and 2 is do not send yet.
+            // This is because students only want to be notified about certain types of update (grades and feedback).
+            $grade->mailed = 2;
             $gid = $DB->insert_record('assign_grades', $grade);
             $grade->id = $gid;
             return $grade;
@@ -3712,6 +3733,7 @@ private function process_save_quick_grades() {
             }
 
             $this->update_grade($grade);
+            $this->notify_grade_modified($grade);
 
             // save outcomes
             if ($CFG->enableoutcomes) {
@@ -4406,6 +4428,7 @@ private function apply_grade_to_user($formdata, $userid) {
             }
         }
         $this->update_grade($grade);
+        $this->notify_grade_modified($grade);
         $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
 
         $this->add_to_log('grade submission', $this->format_grade_for_log($grade));