UPDATE – the code is now on github

One common need when working in PHP is a way to convert an XML document into a serializable array. If you ever tried to serialize() and then unserialize() a SimpleXML or DOMDocument object, you know what I’m talking about.

Assume the following XML snippet:

<tv>
  <show name="Family Guy">
    <dog>Brian</dog>
    <kid>Chris</kid>
    <kid>Meg</kid>
  </show>
</tv>

There’s a quick and dirty way to do convert such a document to an array, using type casting and the JSON functions to ensure there are no exotic values that would cause problems when unserializing:

<?php
  $a = json_decode(json_encode((array) simplexml_load_string($s)),1);
?>

Here is the result for our sample XML, eg if we print_r($a):

Array
(
    [show] => Array
        (
            [@attributes] => Array
                (
                    [name] => Family Guy
                )
            [dog] => Brian
            [kid] => Array
                (
                    [0] => Chris
                    [1] => Meg
                )
        )
)

Pretty nifty, eh? But maybe we want to embed some HTML tags or something crazy along those lines. then we need a CDATA node…

<tv>
  <show name="Family Guy">
    <dog>Brian</dog>
    <kid>Chris</kid>
    <kid>Meg</kid>
    <kid><![CDATA[<em>Stewie</em>]]></kid>
  </show>
</tv>

The snippet of XML above would yield the following:

Array
(
    [show] => Array
        (
            [@attributes] => Array
                (
                    [name] => Family Guy
                )
            [dog] => Brian
            [kid] => Array
                (
                    [0] => Chris
                    [1] => Meg
                    [2] => Array
                        (
                        )
                )
        )
)

That’s not very useful. We got in trouble because the CDATA node, a SimpleXMLElement, is being cast to an array instead of a string. To handle this case while still keeping the nice @attributes notation, we need a slightly more verbose conversion function. Here is my version, hereby released under a do-whatever-but-dont-sue-me license.

<?php
/**
 * convert xml string to php array - useful to get a serializable value
 *
 * @param string $xmlstr
 * @return array
 * @author Adrien aka Gaarf
 */
function xmlstr_to_array($xmlstr) {
  $doc = new DOMDocument();
  $doc->loadXML($xmlstr);
  return domnode_to_array($doc->documentElement);
}
function domnode_to_array($node) {
  $output = array();
  switch ($node->nodeType) {
   case XML_CDATA_SECTION_NODE:
   case XML_TEXT_NODE:
    $output = trim($node->textContent);
   break;
   case XML_ELEMENT_NODE:
    for ($i=0, $m=$node->childNodes->length; $i<$m; $i++) {
     $child = $node->childNodes->item($i);
     $v = domnode_to_array($child);
     if(isset($child->tagName)) {
       $t = $child->tagName;
       if(!isset($output[$t])) {
        $output[$t] = array();
       }
       $output[$t][] = $v;
     }
     elseif($v) {
      $output = (string) $v;
     }
    }
    if(is_array($output)) {
     if($node->attributes->length) {
      $a = array();
      foreach($node->attributes as $attrName => $attrNode) {
       $a[$attrName] = (string) $attrNode->value;
      }
      $output['@attributes'] = $a;
     }
     foreach ($output as $t => $v) {
      if(is_array($v) && count($v)==1 && $t!='@attributes') {
       $output[$t] = $v[0];
      }
     }
    }
   break;
  }
  return $output;
}
?>

and the result, for our Stewie snippet:

Array
(
    [show] => Array
        (
            [@attributes] => Array
                (
                    [name] => Family Guy
                )
            [dog] => Brian
            [kid] => Array
                (
                    [0] => Chris
                    [1] => Meg
                    [2] => <em>Stewie</em>
                )
        )
)

Victory is mine!