I want to send a file this lives on a path outside the web server root directory to the browser. So I will open the file from my PHP code an stream it out to the client.
On the client side this should only happen when clicking on a "open" button or on a link (-tag). In either case I will call a JS-script that should do the magic of showing the file to the client.
How would you implement that?
This is how i stream files from PHP outside of web access i hope this helps you understand how it works
PHP
header('Access-Control-Expose-Headers: filename');
$JSON = file_get_contents('php://input');
$data = json_decode($JSON, TRUE);
//use your json data to find the file your looking for
$file = FULL_PATH_TO_FILE;
$size = filesize($file);
header ( 'Content-Description: File Transfer' );
header("Content-Type: application/force-download");
header ( 'Content-Type: application/octet-stream' );
header ( 'Content-Disposition: attachment; filename=' . str_replace("_", " ", basename ($file)));
header ( 'Expires: 0' );
header ( 'Cache-Control: must-revalidate' );
header ( 'Pragma: public' );
header ( 'Content-Length: ' . filesize ( $file ) );
ob_clean();
flush();
readfile ( $file );
exit();
JS
var data = {
ID: 1,
FileName: “example_file_name.pdf”
}
var req = new XMLHttpRequest();
req.open("POST", `https://api.server.com/download.php`, true);
req.responseType = "blob";
req.onload = (event) => {
var blob = req.response;
var filename = "";
var disposition = req.getResponseHeader('Content-Disposition');
if (disposition && disposition.indexOf('attachment') !== -1) {
var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
var matches = filenameRegex.exec(disposition);
if (matches != null && matches[1]) {
filename = matches[1].replace(/['"]/g, '');
}
}
const href = window.URL.createObjectURL(blob);
var a = document.createElement("a");
a.download = filename;
a.href = href;
a.click();
};
req.send(JSON.stringify(data));
