Escape Special Characters without <> and quotes with PHP

Question

I have an XML/SVG. Part of it:

<text id="p6_segmentMainLabel5-outer" class="p6_segmentMainLabel-outer" style="font-size: 11px; font-family: arial; fill: rgb(170, 170, 170);">BüG [349]</text>

There is a special character Inside of it. How Do I clean the entire XML of such special characters without escaping all the "<" and ">" to < and >? I could make an array of all the characters I want to convert but I would like a mthod that only excludes <> and Quotes to have a clean XML.

Answer 1

Encoding the umlauts does not make your XML "cleaner", but more difficult to read.

Here is not need to encode umlauts and other characters not belonging to ASCII - except if you want to create ASCII XML. This is not needed often.

Use UTF-8 as the encoding for you XML and you will be fine 99% of the time.

If you need ASCII specify the encoding on the XML-API (default is UTF-8):

$dom = new DOMDocument('1.0', 'ASCII');
$dom
  ->appendChild($dom->createElement('text'))
  ->appendChild($dom->createTextNode('ÄÖÜ'));
echo $dom->saveXml();

Output:

<?xml version="1.0" encoding="ASCII"?>
<text>&#196;&#214;&#220;</text>

It is possible to load the XML into a DOM and copy all the nodes to a new DOM defined to use ASCII:

$source = new DOMDocument();
$source->loadXml(
  '<?xml version="1.0" encoding="utf-8" ?><text>ÄÖÜ</text>'
);

$target = new DOMDocument('1.0', 'ASCII');
$target->appendChild(
  $target->importNode(
    $source->documentElement, TRUE
  )
);
echo $target->saveXml();

If you generate XML as text, you can use the htmlentities() function to convert a string.