Download PHP/HTML/CSS to PDF Document - php

Question

Here I have some code, it does as it says and downloads, however only downloads a white blank empty file, and I am trying to use this one Wordpress and must be without a plugin. The script works, but its not downloading any information onto the PDF document, its just a white blank page here is the code, looking for a solution to added Wordpress post to the document, here is the link and the code, ideally I want it to download the page in which the link is executed.
HTML Link
Download file
download.php
<?php
ignore_user_abort(true);
$path = ""; // change the path to fit your websites document structure
$dl_file = preg_replace("([^\w\s\d\-_~,;:\[\]\(\].]|[\.]{2,})", '', $_GET['download_file']); // simple file name validation
$fullPath = $path.$dl_file;
if ($fd = fopen ($fullPath, "r")) {
$fsize = filesize($fullPath);
$path_parts = pathinfo($fullPath);
$ext = strtolower($path_parts["extension"]);
switch ($ext) {
case "pdf":
header("Content-type: application/pdf");
header("Content-Disposition: attachment; filename=\"".$path_parts["basename"]."\""); // use 'attachment' to force a file download
break;
// add more headers for other content types here
default;
header("Content-type: application/octet-stream");
header("Content-Disposition: filename=\"".$path_parts["basename"]."\"");
break;
}
header("Content-length: $fsize");
header("Cache-control: private"); //use this to open files directly
while(!feof($fd)) {
$buffer = fread($fd, 2048);
echo $buffer;
}
}
fclose ($fd);
exit;
?>

Answer 1

DO NOT USE THE CODE ABOVE!
It not only doesn't convert anything into PDF but also allows the world to download arbitrary files readable by the webserver as plaintext. So one could download your mysql database credentials or your FTP password if set in wp-config.php.
Explanation: the code doesn't convert anything. It just takes the content of an arbitrary file and outputs it with a PDF or octet-stream content type. Take a text editor and look at the "PDF" you downloaded.
It looks like you haven't to set the line
$path = ""; // change the path to fit your websites document structure to the full path pointing to some_file.pdf.