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See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?php
// This file is part of Moodle - http://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 <http://www.gnu.org/licenses/>.

/**
 * This file contains the combined document class for the assignfeedback_editpdf plugin.
 *
 * @package   assignfeedback_editpdf
 * @copyright 2017 Andrew Nicols <andrew@nicols.co.uk>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace assignfeedback_editpdf;

defined('MOODLE_INTERNAL') || die();

/**
 * The combined_document class for the assignfeedback_editpdf plugin.
 *
 * @copyright 2017 Andrew Nicols <andrew@nicols.co.uk>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class combined_document {

    /**
     * Status value representing a conversion waiting to start.
     */
    const STATUS_PENDING_INPUT = 0;

    /**
     * Status value representing all documents ready to be combined.
     */
    const STATUS_READY = 1;

    /**
     * Status value representing all documents are ready to be combined as are supported.
     */
    const STATUS_READY_PARTIAL = 3;

    /**
     * Status value representing a successful conversion.
     */
    const STATUS_COMPLETE = 2;

    /**
     * Status value representing a permanent error.
     */
    const STATUS_FAILED = -1;

    /**
     * The list of files which make this document.
     */
    protected $sourcefiles = [];

    /**
     * The resultant combined file.
     */
    protected $combinedfile;

    /**
     * The combination status.
     */
    protected $combinationstatus = null;

    /**
     * The number of pages in the combined PDF.
     */
    protected $pagecount = 0;

    /**
     * Check the current status of the document combination.
     * Note that the combined document may not contain all the source files if some of the
     * source files were not able to be converted. An example is an audio file with a pdf cover sheet. Only
     * the cover sheet will be included in the combined document.
     *
     * @return  int
     */
    public function get_status() {
        if ($this->combinedfile) {
            // The combined file exists. Report success.
            return self::STATUS_COMPLETE;
        }

        if (empty($this->sourcefiles)) {
            // There are no source files to combine.
            return self::STATUS_FAILED;
        }

        if (!empty($this->combinationstatus)) {
            // The combination is in progress and has set a status.
            // Return it instead.
            return $this->combinationstatus;
        }

        $pending = false;
        $partial = false;
        foreach ($this->sourcefiles as $file) {
            // The combined file has not yet been generated.
            // Check the status of each source file.
            if (is_a($file, \core_files\conversion::class)) {
                $status = $file->get('status');
                switch ($status) {
                    case \core_files\conversion::STATUS_IN_PROGRESS:
                    case \core_files\conversion::STATUS_PENDING:
                        $pending = true;
                        break;

                    // There are 4 status flags, so the only remaining one is complete which is fine.
                    case \core_files\conversion::STATUS_FAILED:
                        $partial = true;
                        break;
                }
            }
        }
        if ($pending) {
            return self::STATUS_PENDING_INPUT;
        } else {
            if ($partial) {
                return self::STATUS_READY_PARTIAL;
            }
            return self::STATUS_READY;
        }
    }
    /**
     * Set the completed combined file.
     *
< * @param stored_file $file The completed document for all files to be combined.
> * @param \stored_file $file The completed document for all files to be combined.
* @return $this */ public function set_combined_file($file) { $this->combinedfile = $file; return $this; } /** * Return true of the combined file contained only some of the submission files. * * @return boolean */ public function is_partial_conversion() { $combinedfile = $this->get_combined_file(); if (empty($combinedfile)) { return false; } $filearea = $combinedfile->get_filearea(); return $filearea == document_services::PARTIAL_PDF_FILEAREA; } /** * Retrieve the completed combined file. * * @return stored_file */ public function get_combined_file() { return $this->combinedfile; } /** * Set all source files which are to be combined. *
< * @param stored_file|conversion[] $files The complete list of all source files to be combined.
> * @param \stored_file|conversion[] $files The complete list of all source files to be combined.
* @return $this */ public function set_source_files($files) { $this->sourcefiles = $files; return $this; } /** * Add an additional source file to the end of the existing list. *
< * @param stored_file|conversion $file The file to add to the end of the list.
> * @param \stored_file|conversion $file The file to add to the end of the list.
* @return $this */ public function add_source_file($file) { $this->sourcefiles[] = $file; return $this; } /** * Retrieve the complete list of source files. * * @return stored_file|conversion[] */ public function get_source_files() { return $this->sourcefiles; } /** * Refresh the files. * * This includes polling any pending conversions to see if they are complete. * * @return $this */ public function refresh_files() { $converter = new \core_files\converter(); foreach ($this->sourcefiles as $file) { if (is_a($file, \core_files\conversion::class)) { $status = $file->get('status'); switch ($status) { case \core_files\conversion::STATUS_COMPLETE: continue 2; break; default: $converter->poll_conversion($conversion); } } } return $this; } /** * Combine all source files into a single PDF and store it in the * file_storage API using the supplied contextid and itemid. * * @param int $contextid The contextid for the file to be stored under * @param int $itemid The itemid for the file to be stored under * @return $this */ public function combine_files($contextid, $itemid) { global $CFG; $currentstatus = $this->get_status(); $readystatuslist = [self::STATUS_READY, self::STATUS_READY_PARTIAL]; if ($currentstatus === self::STATUS_FAILED) { $this->store_empty_document($contextid, $itemid); return $this; } else if (!in_array($currentstatus, $readystatuslist)) { // The document is either: // * already combined; or // * pending input being fully converted; or // * unable to continue due to an issue with the input documents. // // Exit early as we cannot continue. return $this; } require_once($CFG->libdir . '/pdflib.php'); $pdf = new pdf(); $files = $this->get_source_files(); $compatiblepdfs = []; foreach ($files as $file) { // Check that each file is compatible and add it to the list. // Note: We drop non-compatible files. $compatiblepdf = false; if (is_a($file, \core_files\conversion::class)) { $status = $file->get('status'); if ($status == \core_files\conversion::STATUS_COMPLETE) { $compatiblepdf = pdf::ensure_pdf_compatible($file->get_destfile()); } } else { $compatiblepdf = pdf::ensure_pdf_compatible($file); } if ($compatiblepdf) { $compatiblepdfs[] = $compatiblepdf; } } $tmpdir = make_request_directory(); $tmpfile = $tmpdir . '/' . document_services::COMBINED_PDF_FILENAME; try { $pagecount = $pdf->combine_pdfs($compatiblepdfs, $tmpfile); $pdf->Close(); } catch (\Exception $e) { // Unable to combine the PDF. debugging('TCPDF could not process the pdf files:' . $e->getMessage(), DEBUG_DEVELOPER); $pdf->Close(); return $this->mark_combination_failed(); } // Verify the PDF. $verifypdf = new pdf(); $verifypagecount = $verifypdf->load_pdf($tmpfile); $verifypdf->Close(); if ($verifypagecount <= 0) { // No pages were found in the combined PDF. return $this->mark_combination_failed(); } // Store the newly created file as a stored_file. $this->store_combined_file($tmpfile, $contextid, $itemid, ($currentstatus == self::STATUS_READY_PARTIAL)); // Note the verified page count. $this->pagecount = $verifypagecount; return $this; } /** * Mark the combination attempt as having encountered a permanent failure. * * @return $this */ protected function mark_combination_failed() { $this->combinationstatus = self::STATUS_FAILED; return $this; } /** * Store the combined file in the file_storage API. * * @param string $tmpfile The path to the file on disk to be stored. * @param int $contextid The contextid for the file to be stored under * @param int $itemid The itemid for the file to be stored under * @param boolean $partial The combined pdf contains only some of the source files. * @return $this */ protected function store_combined_file($tmpfile, $contextid, $itemid, $partial = false) { // Store the file. $record = $this->get_stored_file_record($contextid, $itemid, $partial); $fs = get_file_storage(); // Delete existing files first. $fs->delete_area_files($record->contextid, $record->component, $record->filearea, $record->itemid); // This was a combined pdf. $file = $fs->create_file_from_pathname($record, $tmpfile); $this->set_combined_file($file); return $this; } /** * Store the empty document file in the file_storage API. * * @param int $contextid The contextid for the file to be stored under * @param int $itemid The itemid for the file to be stored under * @return $this */ protected function store_empty_document($contextid, $itemid) { // Store the file. $record = $this->get_stored_file_record($contextid, $itemid); $fs = get_file_storage(); // Delete existing files first. $fs->delete_area_files($record->contextid, $record->component, $record->filearea, $record->itemid); $file = $fs->create_file_from_string($record, base64_decode(document_services::BLANK_PDF_BASE64)); $this->pagecount = 1; $this->set_combined_file($file); return $this; } /** * Get the total number of pages in the combined document. * * If there are no pages, or it is not yet possible to count them a * value of 0 is returned. * * @return int */ public function get_page_count() { if ($this->pagecount) { return $this->pagecount; } $status = $this->get_status(); if ($status === self::STATUS_FAILED) { // The empty document will be returned. return 1; } if ($status !== self::STATUS_COMPLETE) { // No pages yet. return 0; } // Load the PDF to determine the page count. $temparea = make_request_directory(); $tempsrc = $temparea . "/source.pdf"; $this->get_combined_file()->copy_content_to($tempsrc); $pdf = new pdf(); $pagecount = $pdf->load_pdf($tempsrc); $pdf->Close(); if ($pagecount <= 0) { // Something went wrong. Return an empty page count again. return 0; } $this->pagecount = $pagecount; return $this->pagecount; } /** * Get the total number of documents to be combined. * * @return int */ public function get_document_count() { return count($this->sourcefiles); } /** * Helper to fetch the stored_file record. * * @param int $contextid The contextid for the file to be stored under * @param int $itemid The itemid for the file to be stored under * @param boolean $partial The combined file contains only some of the source files. * @return stdClass */ protected function get_stored_file_record($contextid, $itemid, $partial = false) { $filearea = document_services::COMBINED_PDF_FILEAREA; if ($partial) { $filearea = document_services::PARTIAL_PDF_FILEAREA; } return (object) [ 'contextid' => $contextid, 'component' => 'assignfeedback_editpdf', 'filearea' => $filearea, 'itemid' => $itemid, 'filepath' => '/', 'filename' => document_services::COMBINED_PDF_FILENAME, ]; } }