Cookbook

INTRODUCTION

PRACTICAL PHPDOCX

CONVERSION PLUGIN

COOKBOOK

SNIPPETS

API DOCUMENTATION

HTML API DOCUMENTATION

JAVASCRIPT API DOCUMENTATION

XML API DOCUMENTATION

CASE STUDIES

Repair PDF documents

Working with PDF methods such as mergePdf, watermarkPdf, or sign (PDF), requires the documents to be internally correct, that means well-formed, uncorrupted and unprotected.

To repair a PDF document that is not well-formed, the easiest approach is using ghostscript, available for Windows, Linux and macOS.

After installing ghostscript, the command to repair a PDF is:

gs -o document_repaired.pdf -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress document.pdf

This command can be called from PHP using passthru or exec functions.

PDF documents that are not well-formed throw PHP Warnings when calling phpdocx PDF methods. These warnings can be catched using a custom error handler, repair the PDF using ghostscript and call again the phpdocx PDF method with the repaired PDF:

set_error_handler(
    function($errno, $errstr, $errfile, $errline) {
        if (!(error_reporting() & $errno)) {
            // this error code is not included in error_reporting
            return;
        }

        if ($errno === E_DEPRECATED || $errno === E_USER_DEPRECATED) {
            // do not throw an Exception for deprecation warnings
            return;
        }

        throw new \ErrorException($errstr, $errno, 0, $errfile, $errline);
    }
);

$pdf = new PdfUtilities();
$source = 'document.pdf';
try {
    $pdf->watermarkPdf($source, 'output.pdf', 'text', array('text' => 'phpdocx', 'size' => 80));
} catch (\ErrorException $e) {
    // exception thrown if the PDF method generates PHP Warnings because the PDF document is not well-formed
    exec('gs -o document_repaired.pdf -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress ' . $source);
    $pdf->watermarkPdf('document_repaired.pdf', 'output.pdf', 'text', array('text' => 'phpdocx', 'size' => 80));
}

// restore the previous error handler function
restore_error_handler();