Save formated xml to file in PHP - php

Question

I know that there are a ton of questions about this here but every answer i tried didn't fixed my problem
Problem
I have xml saved on a string and i want so save it to a file but don't want the xml to be in a single line i want to write to the file in pritty print
Also there is a bigger problem with this the instead of the this " it shows this " since this file will be loaded in a diferent website i can't have "
Note that the $content variable has " not "
I know that \n doesn't matter but to make it easier to analize the generated xml file i need the xml to be formated
this is what i am using
$dirname = "temp/" . uniqid();
mkdir($dirname);
$filename = $dirname . "/gen.xml";
$doc = new DomDocument($content);
$doc->preserveWhiteSpace = false;
$doc->formatOutput = true;
$doc->save($filename);
header("Cache-Control: public");
header("Content-Description: File Transfer");
header("Content-Length: ". filesize("$filename").";");
header("Content-Disposition: attachment; filename=gen.xml");
header("Content-Type: application/octet-stream; ");
header("Content-Transfer-Encoding: binary");
readfile($filename);
$fh = fopen($filename, 'a');
fclose($fh);
unlink($filename);
rmdir($dirname);
I also tried
header("Content-type: text/xml");
and
file_put_contents

Answer 1

DomDocument's constructor does not accept an xml string - rather, an optional version and encoding.
What you probably want is to load your $content xml string instead:
$doc = new DOMDocument();
$doc->preserveWhiteSpace = false;
$doc->formatOutput = true;
$doc->loadXML($content);
$doc->save($filename);