Question

This javascript function takes JSON and formats it to XML. The data is a long XML string, whic I would like to allow the user to download. I’m trying to use ajax to post the data to a php page wichi will create the file and then allow the user to download it.

 json2xml(eval(data));

JS

 $.ajax({
   type: 'POST',
   url: 'download/functions.php',
   data: xml2,
   dataType: XML
 });

I have used this PHP function to write to a file, but I’m not sure how to now send the js variable to this function.

 $data = $_POST['xml2'];

 writetoxml($data, 'WF-XML'.$current. '.xml'); 

 function writetoxml($stringData, $myFile) {
    $current = date('m-d-Y-g-i-s');
    $fh = fopen('download/'.$myFile, 'w') or die("can't open file");
    fwrite($fh, $stringData);
    fclose($fh);
    download($file);
  }

 function downloadFile($file) {

 if(!file)
 {
     // File doesn't exist, output error
     die('file not found');
 }
 else
 {
     // Set headers
     header("Cache-Control: public");
     header("Content-Description: File Transfer");
     header("Content-Disposition: attachment; filename=$file");
     header("Content-Type: application/csv");
     header("Content-Transfer-Encoding: binary");

     // Read the file from disk
     readfile($file);
     exit;
 }

}

This is currently returning a server 500 error.

Answer 1

Updated:

With your provided jQuery AJAX call:

$.ajax({
   type: 'POST',
   url: 'download/yourphpscript.php',
   data: { xml: xml2 },
   dataType: XML
});

Your PHP would look like this:

<?php
$xml = $_POST['xml'];
// Not sure where you're trying to get $file from

writetoxml($xml, $file);

function writetoxml($stringData, $myFile) {
    $current = date('m-d-Y-g-i-s');
    $fh = fopen('download/'.$myFile, 'w') or die("can't open file");
    fwrite($fh, $stringdata);
    fclose($fh);

    download($file);
}

function download($file)
{
    if (file_exists($file)) {
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename='.basename($file));
        header('Content-Transfer-Encoding: binary');
        header('Expires: 0');
        header('Cache-Control: must-revalidate');
        header('Pragma: public');
        header('Content-Length: ' . filesize($file));
        ob_clean();
        flush();
        readfile($file);
        exit;
    }
}
?>

Try passing an object (in this case { key: value } into the data property of the $.ajax call so that you can reference it by your key. In this case our key is xml so on the PHP side, we grab $_POST['xml'] and that should give you the contents of xml2.

The download code was taken from the PHP docs on readfile(). However, I still can’t help but think there is a better way to accomplish this.

I would HIGHLY recommend against allowing the user to effectively create a web accessible file containing whatever they want on your server. As aforementioned, a clarification of your general goal would be helpful. I think I understand what you’re trying to do but why you are doing it would be nice to know as there may be a better and safer way to accomplish the same result.