From f3dd70d17e1f6da13539e112d0f781547aca61f5 Mon Sep 17 00:00:00 2001
From: maksudr <12033826+maksudr@users.noreply.github.com>
Date: Tue, 28 May 2019 01:33:04 +0100
Subject: [PATCH] Fixes #378 - Enable QR Code without filling Student Password
 field (#381)

* Fix #378 - Removing sesskey requirement for viewing attendance.php

* Fix #378 - Show password icon when only QR code is selected.

* Fix #378 - Refactor/Add functionality for QR Code & No Password
---
 attendance.php |  5 -----
 locallib.php   | 31 +++++++++++++++++++++++++++++++
 password.php   | 17 +++++++++--------
 renderer.php   |  2 +-
 4 files changed, 41 insertions(+), 14 deletions(-)

diff --git a/attendance.php b/attendance.php
index c7b15df..9562543 100644
--- a/attendance.php
+++ b/attendance.php
@@ -60,11 +60,6 @@ if (empty($attforsession->includeqrcode)) {
     $qrpass = ''; // Override qrpass if set, as it is not allowed.
 }
 
-if (empty($qrpass)) {
-    // Sesskey is required on this page when QR code not in use.
-    require_sesskey();
-}
-
 // Check to see if autoassignstatus is in use and no password required.
 if ($attforsession->autoassignstatus && empty($attforsession->studentpassword)) {
     $statusid = attendance_session_get_highest_status($att, $attforsession);
diff --git a/locallib.php b/locallib.php
index bc3a7e7..589cd40 100644
--- a/locallib.php
+++ b/locallib.php
@@ -1041,4 +1041,35 @@ function construct_session_full_date_time($datetime, $duration) {
     $sessinfo .= ' '.attendance_construct_session_time($datetime, $duration);
 
     return $sessinfo;
+}
+
+/**
+ * Render the session password.
+ *
+ * @param stdClass $session
+ */
+function attendance_renderpassword($session) {
+    echo html_writer::tag('h2', get_string('passwordgrp', 'attendance'));
+    echo html_writer::span($session->studentpassword, 'student-password');
+}
+
+/**
+ * Render the session QR code.
+ *
+ * @param stdClass $session
+ */
+function attendance_renderqrcode($session) {
+    global $CFG;
+
+    if (strlen($session->studentpassword) > 0) {
+        $qrcodeurl = $CFG->wwwroot . '/mod/attendance/attendance.php?qrpass=' . $session->studentpassword . '&sessid=' . $session->id;
+    } else {
+        $qrcodeurl = $CFG->wwwroot . '/mod/attendance/attendance.php?sessid=' . $session->id;
+    }
+
+    echo html_writer::tag('h3', get_string('qrcode', 'attendance'));
+
+    $barcode = new TCPDF2DBarcode($qrcodeurl, 'QRCODE');
+    $image = $barcode->getBarcodePngData(15, 15);
+    echo html_writer::img('data:image/png;base64,' . base64_encode($image), get_string('qrcode', 'attendance'));
 }
\ No newline at end of file
diff --git a/password.php b/password.php
index 4e92d9b..f15be09 100644
--- a/password.php
+++ b/password.php
@@ -49,15 +49,16 @@ $PAGE->set_context(context_system::instance());
 $PAGE->set_title(get_string('password', 'attendance'));
 
 echo $OUTPUT->header();
-echo html_writer::tag('h2', get_string('passwordgrp', 'attendance'));
-echo html_writer::span($session->studentpassword, 'student-password');
 
-if (isset($session->includeqrcode) && $session->includeqrcode == 1) {
-    $qrcodeurl = $CFG->wwwroot . '/mod/attendance/attendance.php?qrpass=' . $session->studentpassword . '&sessid=' . $session->id;
-    echo html_writer::tag('h3', get_string('qrcode', 'attendance'));
+$showpassword = (isset($session->studentpassword) && strlen($session->studentpassword) > 0);
+$showqr = (isset($session->includeqrcode) && $session->includeqrcode == 1);
 
-    $barcode = new TCPDF2DBarcode($qrcodeurl, 'QRCODE');
-    $image = $barcode->getBarcodePngData(15, 15);
-    echo html_writer::img('data:image/png;base64,' . base64_encode($image), get_string('qrcode', 'attendance'));
+if ($showpassword) {
+    attendance_renderpassword($session);
 }
+
+if ($showqr) {
+    attendance_renderqrcode($session);
+}
+
 echo $OUTPUT->footer();
diff --git a/renderer.php b/renderer.php
index d11caa9..18d4261 100644
--- a/renderer.php
+++ b/renderer.php
@@ -312,7 +312,7 @@ class mod_attendance_renderer extends plugin_renderer_base {
      */
     private function construct_date_time_actions(attendance_manage_data $sessdata, $sess) {
         $actions = '';
-        if (!empty($sess->studentpassword) &&
+        if ((!empty($sess->studentpassword) || ($sess->includeqrcode == 1)) &&
             (has_capability('mod/attendance:manageattendances', $sessdata->att->context) ||
             has_capability('mod/attendance:takeattendances', $sessdata->att->context) ||
             has_capability('mod/attendance:changeattendances', $sessdata->att->context))) {