Add option for footer with page number

classes/customTCPDF.php

@@ -0,0 +1,51 @@
+<?php
+// This file is part of Moodle - https://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
+
+namespace quiz_essaydownload;
+
+use pdf;
+
+defined('MOODLE_INTERNAL') || die();
+require_once($CFG->libdir . '/pdflib.php');
+
+/**
+ * Override TCPDF in order to have a custom footer that includes the page number.
+ *
+ * @package    quiz_essaydownload
+ * @copyright  2024 Philipp Imhof
+ * @license    https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class customTCPDF extends pdf {
+    /** @var int footer's distance from bottom of page in millimeters */
+    const FOOTER_POSITION = 15;
+
+    // @codingStandardsIgnoreLine
+    public function Footer() {
+        $this->SetY(-self::FOOTER_POSITION);
+
+        // We cannot use getAliasNumPage(), because there seems to be a bug in TCPDF that will cause the
+        // footer to be badly centered. The same is true for getAliasNbPages(), but we don't need that
+        // here.
+        if (empty($this->pagegroups)) {
+            $pageno = $this->PageNo();
+        } else {
+            $pageno = $this->getGroupPageNo();
+        }
+
+        $this->Cell(0, 10, get_string('pagenumber', 'quiz_essaydownload', $pageno), 'T', 0, 'C');
+    }
+
+}

essaydownload_form.php

@@ -172,6 +172,14 @@ protected function pdf_layout_fields(MoodleQuickForm $mform) {
         $mform->addGroup($margingroup, 'margingroup', get_string('margins', 'quiz_essaydownload'), ' ', false);
         $mform->disabledIf('margingroup', 'fileformat', 'neq', 'pdf');
 
+        $mform->addElement(
+            'advcheckbox',
+            'includefooter',
+            get_string('footer', 'quiz_essaydownload'),
+            get_string('includefooter', 'quiz_essaydownload')
+        );
+        $mform->disabledIf('includefooter', 'fileformat', 'neq', 'pdf');
+
         $mform->addElement('select', 'linespacing', get_string('linespacing', 'quiz_essaydownload'), [
             '1' => get_string('linesingle', 'quiz_essaydownload'),
             '1.5' => get_string('lineoneandhalf', 'quiz_essaydownload'),

essaydownload_options.php

@@ -61,6 +61,9 @@ class quiz_essaydownload_options extends quiz_essaydownload_options_parent_class
     /** @var string how to organise the sub folders in the archive (by question or by attempt) */
     public $groupby = 'byattempt';
 
+    /** @var bool whether a footer containing the page number should be added to PDFs */
+    public $includefooter = false;
+
     /** @var float line spacing for PDF export */
     public $linespacing = 1;
 
@@ -118,6 +121,7 @@ public function get_initial_form_data() {
         $toform->font = $this->font;
         $toform->fontsize = $this->fontsize;
         $toform->groupby = $this->groupby;
+        $toform->includefooter = $this->includefooter;
         $toform->linespacing = $this->linespacing;
         $toform->marginbottom = $this->marginbottom;
         $toform->marginleft = $this->marginleft;
@@ -144,6 +148,7 @@ public function setup_from_form_data($fromform): void {
         $this->font = $fromform->font ?? '';
         $this->fontsize = $fromform->fontsize ?? '';
         $this->groupby = $fromform->groupby;
+        $this->includefooter = $fromform->includefooter;
         $this->linespacing = $fromform->linespacing ?? '';
         $this->marginbottom = $fromform->marginbottom ?? '';
         $this->marginleft = $fromform->marginleft ?? '';
@@ -166,6 +171,7 @@ public function setup_from_params() {
         $this->font = optional_param('font', $this->font, PARAM_ALPHA);
         $this->fontsize = optional_param('fontsize', $this->fontsize, PARAM_INT);
         $this->groupby = optional_param('groupby', $this->groupby, PARAM_ALPHA);
+        $this->includefooter = optional_param('includefooter', $this->includefooter, PARAM_BOOL);
         $this->linespacing = optional_param('linespacing', $this->linespacing, PARAM_FLOAT);
         $this->marginbottom = optional_param('marginbottom', $this->marginbottom, PARAM_INT);
         $this->marginleft = optional_param('marginleft', $this->marginleft, PARAM_INT);

lang/en/quiz_essaydownload.php

@@ -45,11 +45,13 @@
 $string['fontserif'] = 'Serif';
 $string['fontsize'] = 'Font size (points)';
 $string['fontsize_help'] = 'Note that when using the original HTML formatted text, the actual font size may still be different, according to the formatting';
+$string['footer'] = 'Footer';
 $string['generaloptions'] = 'General options';
 $string['groupby'] = 'Group by';
 $string['groupby_help'] = 'The archive can be structured by question or by attempt:<ul><li>If you group by question, the archive will have a folder for every question. Inside each folder, you will have a folder for every attempt.</li><li>If you group by attempt, the archive will have a folder for every attempt. Inside each folder, you will have a folder for every question.</li></ul>';
 $string['includeattachments'] = 'Also download possible attachments included in a student\'s answer.';
 $string['includeattachments_help'] = 'Any attachment is provided as-is. Please note that attachments might contain malware.';
+$string['includefooter'] = 'Add footer with page number to each page.';
 $string['includequestiontext'] = 'Also include question text.';
 $string['includequestiontext_help'] = 'Including the question text might be useful if your quiz uses random questions.';
 $string['lastfirst'] = 'Last name - First name';
@@ -64,6 +66,7 @@
 $string['page'] = 'Page format';
 $string['pagea4'] = 'A4';
 $string['pageletter'] = 'Letter';
+$string['pagenumber'] = 'Page {$a}';
 $string['pdfoptions'] = 'PDF settings';
 $string['plugindescription'] = 'Download text answers and attachment files submitted in response to essay questions in a quiz.';
 $string['pluginname'] = 'Essay responses downloader plugin (quiz_essaydownload)';

report.php

@@ -25,6 +25,7 @@
 
 use core_files\archive_writer;
 use core\dml\sql_join;
+use quiz_essaydownload\customTCPDF;
 
 defined('MOODLE_INTERNAL') || die();
 
@@ -40,6 +41,7 @@ class_alias('\quiz_attempts_report', '\quiz_essaydownload_report_parent_alias');
     class_alias('\quiz_attempt', '\quiz_essaydownload_quiz_attempt_alias');
 }
 
+require_once($CFG->dirroot . '/mod/quiz/report/essaydownload/classes/customTCPDF.php');
 require_once($CFG->dirroot . '/mod/quiz/report/essaydownload/essaydownload_form.php');
 require_once($CFG->dirroot . '/mod/quiz/report/essaydownload/essaydownload_options.php');
 require_once($CFG->libdir . '/pdflib.php');
@@ -505,7 +507,7 @@ protected function generate_pdf(string $text, string $header = '', string $subhe
             $text = $this->workaround_atto_font_size_issue($text);
         }
 
-        $doc = new pdf('P', 'mm', $this->options->pageformat);
+        $doc = new customTCPDF('P', 'mm', $this->options->pageformat);
 
         $doc->SetCreator('quiz_essaydownload plugin for Moodle LMS');
         $doc->SetAuthor($author);
@@ -523,7 +525,6 @@ protected function generate_pdf(string $text, string $header = '', string $subhe
             $this->options->margintop + $this->options->linespacing * $this->options->fontsize,
             $this->options->marginright
         );
-        $doc->setPrintFooter(false);
 
         if ($this->options->font === 'serif') {
             $fontname = 'freeserif';
@@ -534,10 +535,19 @@ protected function generate_pdf(string $text, string $header = '', string $subhe
         }
         $doc->SetFont($fontname, '', $this->options->fontsize);
         $doc->setHeaderFont([$fontname, '', $this->options->fontsize]);
-
         $doc->setHeaderData('', 0, $header, $subheader);
-        $doc->setFooterData();
-        $doc->SetAutoPageBreak(true, $this->options->marginbottom);
+
+        // The user may choose to add a footer to each page, by default, there is none and thus no
+        // need for additional space.
+        $doc->setPrintFooter(false);
+        $spaceforfooter = 0;
+        if ($this->options->includefooter) {
+            $doc->setPrintFooter(true);
+            $spaceforfooter = customTCPDF::FOOTER_POSITION;
+            // Using 80% of the base font size seems good.
+            $doc->setFooterFont([$fontname, '', round(0.8 * $this->options->fontsize)]);
+        }
+        $doc->SetAutoPageBreak(true, $this->options->marginbottom + $spaceforfooter);
 
         $doc->AddPage();
         $linespacebase = 1.25;

tests/behat/form.feature

@@ -59,6 +59,7 @@ Feature: Validation and display of the form
     And the "marginright" "field" should be disabled
     And the "margintop" "field" should be disabled
     And the "marginbottom" "field" should be disabled
+    And the "includefooter" "field" should be disabled
     And the "linespacing" "select" should be disabled
     And the "font" "select" should be disabled
     And the "fontsize" "field" should be disabled