You do not need to change your file, but you cannot use it directly due to security issues. If I would write a Javascript which reads your secret files and you load my page, all your secrets would be revealed, therefore, if you want to load a file, you either have to allow your user to upload it and once the user uploads the file do your logic, or, you can request it via AJAX.
How to upload a file
An example for this is
<!DOCTYPE html>
<html>
<body onload="myFunction()">
<input type="file" id="myFile" multiple size="50" onchange="myFunction()">
<p id="demo"></p>
<script>
function myFunction(){
var x = document.getElementById("myFile");
var txt = "";
if ('files' in x) {
if (x.files.length == 0) {
txt = "Select one or more files.";
} else {
for (var i = 0; i < x.files.length; i++) {
txt += "<br><strong>" + (i+1) + ". file</strong><br>";
var file = x.files[i];
if ('name' in file) {
txt += "name: " + file.name + "<br>";
}
if ('size' in file) {
txt += "size: " + file.size + " bytes <br>";
}
}
}
}
else {
if (x.value == "") {
txt += "Select one or more files.";
} else {
txt += "The files property is not supported by your browser!";
txt += "<br>The path of the selected file: " + x.value; // If the browser does not support the files property, it will return the path of the selected file instead.
}
}
document.getElementById("demo").innerHTML = txt;
}
</script>
<p><strong>Tip:</strong> Use the Control or the Shift key to select multiple files.</p>
</body>
</html>
source: https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_fileupload_files
Getting the file via AJAX
In order to do that, you will need to:
- send an AJAX request in your javascript code
- parse the request and send back the file via PHP
- do your logic in Javascript when the request is responded
Example:
HTML
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Download POST Request</title>
</head>
<body>
Enter a text and click the button: <input type="text" id="content" value="Text for the generated pdf">
<button id="download">Send AJAX Request and download file</button>
<script>
document.getElementById('download').addEventListener('click', function () {
var content = document.getElementById('content').value;
var request = new XMLHttpRequest();
request.open('POST', '../server/', true);
request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
request.responseType = 'blob';
request.onload = function() {
// Only handle status code 200
if(request.status === 200) {
// Try to find out the filename from the content disposition `filename` value
var disposition = request.getResponseHeader('content-disposition');
var matches = /"([^"]*)"/.exec(disposition);
var filename = (matches != null && matches[1] ? matches[1] : 'file.pdf');
// The actual download
var blob = new Blob([request.response], { type: 'application/pdf' });
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
link.download = filename;
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
// some error handling should be done here...
};
request.send('content=' + content);
});
</script>
</body>
</html>
PHP
<?php
require_once 'vendor/autoload.php';
if($_SERVER['REQUEST_METHOD'] === 'POST') {
header('Content-type: application/pdf');
http_response_code(200);
// Contents
$pdfContent = !empty($_POST['content']) ? $_POST['content'] : 'no content specified';
// Generate the PDOF
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10, $pdfContent);
return $pdf->Output(null, 'foobar-' . time() . '.pdf');
}
// Bad method
http_response_code(405);
exit();
Source: https://nehalist.io/downloading-files-from-post-requests/
You will of course need to modify the code to comply to your needs. Reading a tutorial would not hurt.
