Gradebook - Fix export results popup BT#18440

main/gradebook/gradebook_flatview.php

@@ -284,7 +284,7 @@ if (isset($_GET['selectcat']) && ($_SESSION['studentview'] === 'teacherview')) {
                     height:300,
                     buttons: {
                         "'.addslashes(get_lang('Download')).'": function() {
-                            var onlyScore = $("input[name=only_score]:checked").val();
+                            let onlyScore = $("input[name=only_score]").prop("checked") ? 1 : 0;
                             location.href = targetUrl+"&only_score="+onlyScore;
                             $(this).dialog("close");
                         }

main/gradebook/lib/fe/displaygradebook.php

@@ -258,12 +258,10 @@ class DisplayGradebook
                 null,
                 ['class' => 'form-vertical']
             );
-            $form->addElement(
-                'checkbox',
+            $form->addCheckBox(
                 'only_score',
                 null,
-                get_lang('OnlyNumbers'),
-                '0'
+                get_lang('OnlyNumbers')
             );
             $dialog .= $form->returnForm();
             $dialog .= '</div>';