File: /home/iestorre/moodleAW/moodle01/mod/assign/feedback/editpdf/classes/document_services.php
<?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 ingest manager for the assignfeedback_editpdf plugin
*
* @package assignfeedback_editpdf
* @copyright 2012 Davo Smith
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace assignfeedback_editpdf;
/**
* Functions for generating the annotated pdf.
*
* This class controls the ingest of student submission files to a normalised
* PDF 1.4 document with all submission files concatinated together. It also
* provides the functions to generate a downloadable pdf with all comments and
* annotations embedded.
* @copyright 2012 Davo Smith
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class document_services {
/** File area for generated pdf */
const FINAL_PDF_FILEAREA = 'download';
/** File area for combined pdf */
const COMBINED_PDF_FILEAREA = 'combined';
/** File area for page images */
const PAGE_IMAGE_FILEAREA = 'pages';
/** File area for readonly page images */
const PAGE_IMAGE_READONLY_FILEAREA = 'readonlypages';
/** Filename for combined pdf */
const COMBINED_PDF_FILENAME = 'combined.pdf';
/**
* This function will take an int or an assignment instance and
* return an assignment instance. It is just for convenience.
* @param int|\assign $assignment
* @return assign
*/
private static function get_assignment_from_param($assignment) {
global $CFG;
require_once($CFG->dirroot . '/mod/assign/locallib.php');
if (!is_object($assignment)) {
$cm = \get_coursemodule_from_instance('assign', $assignment, 0, false, MUST_EXIST);
$context = \context_module::instance($cm->id);
$assignment = new \assign($context, null, null);
}
return $assignment;
}
/**
* Get a hash that will be unique and can be used in a path name.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
*/
private static function hash($assignment, $userid, $attemptnumber) {
if (is_object($assignment)) {
$assignmentid = $assignment->get_instance()->id;
} else {
$assignmentid = $assignment;
}
return sha1($assignmentid . '_' . $userid . '_' . $attemptnumber);
}
/**
* This function will search for all files that can be converted
* and concatinated into a PDF (1.4) - for any submission plugin
* for this students attempt.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return array(stored_file)
*/
public static function list_compatible_submission_files_for_attempt($assignment, $userid, $attemptnumber) {
global $USER, $DB;
$assignment = self::get_assignment_from_param($assignment);
// Capability checks.
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
$files = array();
if ($assignment->get_instance()->teamsubmission) {
$submission = $assignment->get_group_submission($userid, 0, false);
} else {
$submission = $assignment->get_user_submission($userid, false);
}
$user = $DB->get_record('user', array('id' => $userid));
// User has not submitted anything yet.
if (!$submission) {
return $files;
}
// Ask each plugin for it's list of files.
foreach ($assignment->get_submission_plugins() as $plugin) {
if ($plugin->is_enabled() && $plugin->is_visible()) {
$pluginfiles = $plugin->get_files($submission, $user);
foreach ($pluginfiles as $filename => $file) {
if (($file instanceof \stored_file) && ($file->get_mimetype() === 'application/pdf')) {
$files[$filename] = $file;
}
}
}
}
return $files;
}
/**
* This function return the combined pdf for all valid submission files.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return stored_file
*/
public static function get_combined_pdf_for_attempt($assignment, $userid, $attemptnumber) {
global $USER, $DB;
$assignment = self::get_assignment_from_param($assignment);
// Capability checks.
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
if ($assignment->get_instance()->teamsubmission) {
$submission = $assignment->get_group_submission($userid, 0, false);
} else {
$submission = $assignment->get_user_submission($userid, false);
}
$contextid = $assignment->get_context()->id;
$component = 'assignfeedback_editpdf';
$filearea = self::COMBINED_PDF_FILEAREA;
$itemid = $grade->id;
$filepath = '/';
$filename = self::COMBINED_PDF_FILENAME;
$fs = \get_file_storage();
$combinedpdf = $fs->get_file($contextid, $component, $filearea, $itemid, $filepath, $filename);
if (!$combinedpdf ||
($submission && ($combinedpdf->get_timemodified() < $submission->timemodified))) {
return self::generate_combined_pdf_for_attempt($assignment, $userid, $attemptnumber);
}
return $combinedpdf;
}
/**
* This function will take all of the compatible files for a submission
* and combine them into one PDF.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return stored_file
*/
public static function generate_combined_pdf_for_attempt($assignment, $userid, $attemptnumber) {
global $CFG;
require_once($CFG->libdir . '/pdflib.php');
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
$files = self::list_compatible_submission_files_for_attempt($assignment, $userid, $attemptnumber);
$pdf = new pdf();
if (!$files) {
// No valid submission files - create an empty pdf.
$pdf->AddPage();
} else {
// Create a mega joined PDF.
$compatiblepdfs = array();
foreach ($files as $file) {
$compatiblepdf = pdf::ensure_pdf_compatible($file);
if ($compatiblepdf) {
array_push($compatiblepdfs, $compatiblepdf);
}
}
$tmpdir = \make_temp_directory('assignfeedback_editpdf/combined/' . self::hash($assignment, $userid, $attemptnumber));
$tmpfile = $tmpdir . '/' . self::COMBINED_PDF_FILENAME;
@unlink($tmpfile);
try {
$pagecount = $pdf->combine_pdfs($compatiblepdfs, $tmpfile);
} catch (\Exception $e) {
debugging('TCPDF could not process the pdf files:' . $e->getMessage(), DEBUG_DEVELOPER);
// TCPDF does not recover from errors so we need to re-initialise the class.
$pagecount = 0;
}
if ($pagecount == 0) {
// We at least want a single blank page.
debugging('TCPDF did not produce a valid pdf:' . $tmpfile . '. Replacing with a blank pdf.', DEBUG_DEVELOPER);
$pdf = new pdf();
$pdf->AddPage();
@unlink($tmpfile);
$files = false;
}
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$record = new \stdClass();
$record->contextid = $assignment->get_context()->id;
$record->component = 'assignfeedback_editpdf';
$record->filearea = self::COMBINED_PDF_FILEAREA;
$record->itemid = $grade->id;
$record->filepath = '/';
$record->filename = self::COMBINED_PDF_FILENAME;
$fs = \get_file_storage();
$fs->delete_area_files($record->contextid, $record->component, $record->filearea, $record->itemid);
// Detect corrupt generated pdfs and replace with a blank one.
if ($files) {
$pagecount = $pdf->load_pdf($tmpfile);
if ($pagecount <= 0) {
$files = false;
}
}
if (!$files) {
// This was a blank pdf.
unset($pdf);
$pdf = new pdf();
$content = $pdf->Output(self::COMBINED_PDF_FILENAME, 'S');
$file = $fs->create_file_from_string($record, $content);
} else {
// This was a combined pdf.
$file = $fs->create_file_from_pathname($record, $tmpfile);
@unlink($tmpfile);
// Test the generated file for correctness.
$compatiblepdf = pdf::ensure_pdf_compatible($file);
}
return $file;
}
/**
* This function will return the number of pages of a pdf.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @param bool $readonly When true we get the number of pages for the readonly version.
* @return int number of pages
*/
public static function page_number_for_attempt($assignment, $userid, $attemptnumber, $readonly = false) {
global $CFG;
require_once($CFG->libdir . '/pdflib.php');
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
// When in readonly we can return the number of images in the DB because they should already exist,
// if for some reason they do not, then we proceed as for the normal version.
if ($readonly) {
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$fs = get_file_storage();
$files = $fs->get_directory_files($assignment->get_context()->id, 'assignfeedback_editpdf',
self::PAGE_IMAGE_READONLY_FILEAREA, $grade->id, '/');
$pagecount = count($files);
if ($pagecount > 0) {
return $pagecount;
}
}
// Get a combined pdf file from all submitted pdf files.
$file = self::get_combined_pdf_for_attempt($assignment, $userid, $attemptnumber);
if (!$file) {
\print_error('Could not generate combined pdf.');
}
// Store the combined pdf file somewhere to be opened by tcpdf.
$tmpdir = \make_temp_directory('assignfeedback_editpdf/pagetotal/'
. self::hash($assignment, $userid, $attemptnumber));
$combined = $tmpdir . '/' . self::COMBINED_PDF_FILENAME;
$file->copy_content_to($combined); // Copy the file.
// Get the total number of pages.
$pdf = new pdf();
$pagecount = $pdf->set_pdf($combined);
// Delete temporary folders and files.
@unlink($combined);
@rmdir($tmpdir);
return $pagecount;
}
/**
* This function will generate and return a list of the page images from a pdf.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return array(stored_file)
*/
public static function generate_page_images_for_attempt($assignment, $userid, $attemptnumber) {
global $CFG;
require_once($CFG->libdir . '/pdflib.php');
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
// Need to generate the page images - first get a combined pdf.
$file = self::get_combined_pdf_for_attempt($assignment, $userid, $attemptnumber);
if (!$file) {
throw new \moodle_exception('Could not generate combined pdf.');
}
$tmpdir = \make_temp_directory('assignfeedback_editpdf/pageimages/' . self::hash($assignment, $userid, $attemptnumber));
$combined = $tmpdir . '/' . self::COMBINED_PDF_FILENAME;
$file->copy_content_to($combined); // Copy the file.
$pdf = new pdf();
$pdf->set_image_folder($tmpdir);
$pagecount = $pdf->set_pdf($combined);
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$record = new \stdClass();
$record->contextid = $assignment->get_context()->id;
$record->component = 'assignfeedback_editpdf';
$record->filearea = self::PAGE_IMAGE_FILEAREA;
$record->itemid = $grade->id;
$record->filepath = '/';
$fs = \get_file_storage();
$files = array();
for ($i = 0; $i < $pagecount; $i++) {
$image = $pdf->get_image($i);
$record->filename = basename($image);
$files[$i] = $fs->create_file_from_pathname($record, $tmpdir . '/' . $image);
@unlink($tmpdir . '/' . $image);
}
@unlink($combined);
@rmdir($tmpdir);
return $files;
}
/**
* This function returns a list of the page images from a pdf.
*
* The readonly version is different than the normal one. The readonly version contains a copy
* of the pages in the state they were when the PDF was annotated, by doing so we prevent the
* the pages that are displayed to change as soon as the submission changes.
*
* Though there is an edge case, if the PDF was annotated before MDL-45580, then it is possible
* that we do not find any readonly version of the pages. In that case, we will get the normal
* pages and copy them to the readonly area. This ensures that the pages will remain in that
* state until the submission is updated. When the normal files do not exist, we throw an exception
* because the readonly pages should only ever be displayed after a teacher has annotated the PDF,
* they would not exist until they do.
*
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @param bool $readonly If true, then we are requesting the readonly version.
* @return array(stored_file)
*/
public static function get_page_images_for_attempt($assignment, $userid, $attemptnumber, $readonly = false) {
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
if ($assignment->get_instance()->teamsubmission) {
$submission = $assignment->get_group_submission($userid, 0, false);
} else {
$submission = $assignment->get_user_submission($userid, false);
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$contextid = $assignment->get_context()->id;
$component = 'assignfeedback_editpdf';
$itemid = $grade->id;
$filepath = '/';
$filearea = self::PAGE_IMAGE_FILEAREA;
$fs = \get_file_storage();
// If we are after the readonly pages...
$copytoreadonly = false;
if ($readonly) {
$filearea = self::PAGE_IMAGE_READONLY_FILEAREA;
if ($fs->is_area_empty($contextid, $component, $filearea, $itemid)) {
// We have a problem here, we were supposed to find the files...
// let's fallback on the other area, and copy the files to the readonly area.
$copytoreadonly = true;
$filearea = self::PAGE_IMAGE_FILEAREA;
}
}
$files = $fs->get_directory_files($contextid, $component, $filearea, $itemid, $filepath);
$pages = array();
if (!empty($files)) {
$first = reset($files);
if (!$readonly && $first->get_timemodified() < $submission->timemodified) {
// Image files are stale, we need to regenerate them, except in readonly mode.
// We also need to remove the draft annotations and comments associated with this attempt.
$fs->delete_area_files($contextid, $component, $filearea, $itemid);
page_editor::delete_draft_content($itemid);
$files = array();
} else {
// Need to reorder the files following their name.
// because get_directory_files() return a different order than generate_page_images_for_attempt().
foreach($files as $file) {
// Extract the page number from the file name image_pageXXXX.png.
preg_match('/page([\d]+)\./', $file->get_filename(), $matches);
if (empty($matches) or !is_numeric($matches[1])) {
throw new \coding_exception("'" . $file->get_filename()
. "' file hasn't the expected format filename: image_pageXXXX.png.");
}
$pagenumber = (int)$matches[1];
// Save the page in the ordered array.
$pages[$pagenumber] = $file;
}
ksort($pages);
if ($copytoreadonly) {
self::copy_pages_to_readonly_area($assignment, $grade);
}
}
}
if (empty($pages)) {
if ($readonly) {
// This should never happen, there should be a version of the pages available
// whenever we are requesting the readonly version.
throw new \moodle_exception('Could not find readonly pages for grade ' . $grade->id);
}
$pages = self::generate_page_images_for_attempt($assignment, $userid, $attemptnumber);
}
return $pages;
}
/**
* This function returns sensible filename for a feedback file.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return string
*/
protected static function get_downloadable_feedback_filename($assignment, $userid, $attemptnumber) {
global $DB;
$assignment = self::get_assignment_from_param($assignment);
$groupmode = groups_get_activity_groupmode($assignment->get_course_module());
$groupname = '';
if ($groupmode) {
$groupid = groups_get_activity_group($assignment->get_course_module(), true);
$groupname = groups_get_group_name($groupid).'-';
}
if ($groupname == '-') {
$groupname = '';
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
if ($assignment->is_blind_marking()) {
$prefix = $groupname . get_string('participant', 'assign');
$prefix = str_replace('_', ' ', $prefix);
$prefix = clean_filename($prefix . '_' . $assignment->get_uniqueid_for_user($userid) . '_');
} else {
$prefix = $groupname . fullname($user);
$prefix = str_replace('_', ' ', $prefix);
$prefix = clean_filename($prefix . '_' . $assignment->get_uniqueid_for_user($userid) . '_');
}
$prefix .= $grade->attemptnumber;
return $prefix . '.pdf';
}
/**
* This function takes the combined pdf and embeds all the comments and annotations.
*
* This also moves the annotations and comments from drafts to not drafts. And it will
* copy all the images stored to the readonly area, so that they can be viewed online, and
* not be overwritten when a new submission is sent.
*
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return stored_file
*/
public static function generate_feedback_document($assignment, $userid, $attemptnumber) {
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
if (!$assignment->can_grade()) {
\print_error('nopermission');
}
// Need to generate the page images - first get a combined pdf.
$file = self::get_combined_pdf_for_attempt($assignment, $userid, $attemptnumber);
if (!$file) {
throw new \moodle_exception('Could not generate combined pdf.');
}
$tmpdir = \make_temp_directory('assignfeedback_editpdf/final/' . self::hash($assignment, $userid, $attemptnumber));
$combined = $tmpdir . '/' . self::COMBINED_PDF_FILENAME;
$file->copy_content_to($combined); // Copy the file.
$pdf = new pdf();
$fs = \get_file_storage();
$stamptmpdir = \make_temp_directory('assignfeedback_editpdf/stamps/' . self::hash($assignment, $userid, $attemptnumber));
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
// Copy any new stamps to this instance.
if ($files = $fs->get_area_files($assignment->get_context()->id,
'assignfeedback_editpdf',
'stamps',
$grade->id,
"filename",
false)) {
foreach ($files as $file) {
$filename = $stamptmpdir . '/' . $file->get_filename();
$file->copy_content_to($filename); // Copy the file.
}
}
$pagecount = $pdf->set_pdf($combined);
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
page_editor::release_drafts($grade->id);
for ($i = 0; $i < $pagecount; $i++) {
$pdf->copy_page();
$comments = page_editor::get_comments($grade->id, $i, false);
$annotations = page_editor::get_annotations($grade->id, $i, false);
foreach ($comments as $comment) {
$pdf->add_comment($comment->rawtext,
$comment->x,
$comment->y,
$comment->width,
$comment->colour);
}
foreach ($annotations as $annotation) {
$pdf->add_annotation($annotation->x,
$annotation->y,
$annotation->endx,
$annotation->endy,
$annotation->colour,
$annotation->type,
$annotation->path,
$stamptmpdir);
}
}
fulldelete($stamptmpdir);
$filename = self::get_downloadable_feedback_filename($assignment, $userid, $attemptnumber);
$filename = clean_param($filename, PARAM_FILE);
$generatedpdf = $tmpdir . '/' . $filename;
$pdf->save_pdf($generatedpdf);
$record = new \stdClass();
$record->contextid = $assignment->get_context()->id;
$record->component = 'assignfeedback_editpdf';
$record->filearea = self::FINAL_PDF_FILEAREA;
$record->itemid = $grade->id;
$record->filepath = '/';
$record->filename = $filename;
// Only keep one current version of the generated pdf.
$fs->delete_area_files($record->contextid, $record->component, $record->filearea, $record->itemid);
$file = $fs->create_file_from_pathname($record, $generatedpdf);
// Cleanup.
@unlink($generatedpdf);
@unlink($combined);
@rmdir($tmpdir);
self::copy_pages_to_readonly_area($assignment, $grade);
return $file;
}
/**
* Copy the pages image to the readonly area.
*
* @param int|\assign $assignment The assignment.
* @param \stdClass $grade The grade record.
* @return void
*/
public static function copy_pages_to_readonly_area($assignment, $grade) {
$fs = get_file_storage();
$assignment = self::get_assignment_from_param($assignment);
$contextid = $assignment->get_context()->id;
$component = 'assignfeedback_editpdf';
$itemid = $grade->id;
// Get all the pages.
$originalfiles = $fs->get_area_files($contextid, $component, self::PAGE_IMAGE_FILEAREA, $itemid);
if (empty($originalfiles)) {
// Nothing to do here...
return;
}
// Delete the old readonly files.
$fs->delete_area_files($contextid, $component, self::PAGE_IMAGE_READONLY_FILEAREA, $itemid);
// Do the copying.
foreach ($originalfiles as $originalfile) {
$fs->create_file_from_storedfile(array('filearea' => self::PAGE_IMAGE_READONLY_FILEAREA), $originalfile);
}
}
/**
* This function returns the generated pdf (if it exists).
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return stored_file
*/
public static function get_feedback_document($assignment, $userid, $attemptnumber) {
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$contextid = $assignment->get_context()->id;
$component = 'assignfeedback_editpdf';
$filearea = self::FINAL_PDF_FILEAREA;
$itemid = $grade->id;
$filepath = '/';
$fs = \get_file_storage();
$files = $fs->get_area_files($contextid,
$component,
$filearea,
$itemid,
"itemid, filepath, filename",
false);
if ($files) {
return reset($files);
}
return false;
}
/**
* This function deletes the generated pdf for a student.
* @param int|\assign $assignment
* @param int $userid
* @param int $attemptnumber (-1 means latest attempt)
* @return bool
*/
public static function delete_feedback_document($assignment, $userid, $attemptnumber) {
$assignment = self::get_assignment_from_param($assignment);
if (!$assignment->can_view_submission($userid)) {
\print_error('nopermission');
}
if (!$assignment->can_grade()) {
\print_error('nopermission');
}
$grade = $assignment->get_user_grade($userid, true, $attemptnumber);
$contextid = $assignment->get_context()->id;
$component = 'assignfeedback_editpdf';
$filearea = self::FINAL_PDF_FILEAREA;
$itemid = $grade->id;
$fs = \get_file_storage();
return $fs->delete_area_files($contextid, $component, $filearea, $itemid);
}
}