ethics-canvas/canvas/mpdf/makepdf.php

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);


// require composer autoload
require __DIR__ . '/vendor/autoload.php';

$mpdf = new mPDF();
$stylesheet = file_get_contents('canvas-pdf.css');

$mpdf->WriteHTML($stylesheet,1);

$url = urldecode($_REQUEST['url']);

// To prevent anyone else using your script to create their PDF files

// if (!preg_match('/^http:\/\/www\.mydomain\.com/', $url)) {
//   die("Access denied");
// }

// For $_POST i.e. forms with fields

if (count($_POST) > 0) {

    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1 );

    foreach($_POST as $name => $post) {
      $formvars = array($name => $post . " \n");
    }

    curl_setopt($ch, CURLOPT_POSTFIELDS, $formvars);
    $html = curl_exec($ch);
    curl_close($ch);

} elseif (ini_get('allow_url_fopen')) {
    $html = file_get_contents($url);

} else {
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt ( $ch , CURLOPT_RETURNTRANSFER , 1 );
    $html = curl_exec($ch);
    curl_close($ch);
}

$mpdf = new mPDF();

$mpdf->useSubstitutions = true; // optional - just as an example
$mpdf->SetHeader($url . "\n\n" . 'Page {PAGENO}');  // optional - just as an example
//$mpdf->CSSselectMedia='mpdf'; // assuming you used this in the document header
$mpdf->setBasePath($url);
$mpdf->WriteHTML($html);

$mpdf->Output();