/**
* 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);
$pagecount = $pdf->combine_pdfs($compatiblepdfs, $tmpfile);
if ($pagecount == 0) {
// We at least want a single blank page.
$pdf->AddPage();
@unlink($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, $record->itemid);
if (!$files) {
// This was a blank 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);
}
return $file;
}
/**
* 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;
}