php-XML DomElement无法修饰

Question

Im trying to create a XML file using php.

When I print my xml it prints it all in one line and not in proper format.

$xml = new DomDocument();
**$xml->preserveWhiteSpace = false;
$xml->FormatOutput = true;**

$parent = $xml->createElement("foo");
$parent->setAttribute("xmlns", "http://");
$parent->setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
$parent->setAttribute("xsi:schemaLocation", "link");
$xml->appendChild($parent);
$child = $xml->createElement("foo1");
$parent->appendChild($child);
$subchile = $xml->createElement($foo);
$child->appendChild($subchile);
$s_c = $xml->createElement("foo3",$foo3);
$subchile->appendChild($s_c);

echo "<xmp>" . $xml->saveXML() . "<xml>";    
$xml->save($file_name)

it prints everything without indentations etc.

I read other questions here and followed the answers but still nothing. Can you help?

Answer 1

changed $xml->FormatOutput = true; ---> $xml->formatOutput = true;