Write to file and send AJAX response at once - php

Question

UPDATE:
I used another solution to write my data into a file. It seems that I can't echo data while AJAX is waiting for a response. So I now use fwrite.
$fileHandle = '';
$fileHandle = fopen("export.txt","w");
fwrite($fileHandle, $export);
Original:
Hi there,
maybe my logic is wrong.
I make an AJAX call to get data from another URL.
That worked so far.
But now I want to add an file export also.
$handler = new MyHandler();
// Step 1: get data from URL
$dataAjax = $handler->getData($_POST['data']);
// Step 2: write the data into a text file to provide a download
$handler->writeToText($dataAjax);
echo json_encode($dataAjax);
Now the console shows me a "parserError" because my JSON data contains also the string I wanted to write into the file. That's bad and unwanted.
This below is just a test how I want to write my data into a txt file:
function writeToText($data)
{
header("Content-type: text/plain");
header("Content-Disposition: attachment; filename=export.txt");
header("Pragma: no-cache");
header("Expires: 0");
$title = "";
$title .= "Name,Quantity,Model,Price,Weight,Status"."\n";
echo $title;
}
That is how the error looks like:
{
"readyState": 4,
"responseText": "Name,Quantity,Model,Price,Weight,Status\n[{\"domain\":\"Text\",\"name\":\"Banana\}]",
"status": 200,
"statusText": "OK"
}
parsererror