Is there any way to convert json to xml in PHP?

Question

If you're willing to use the XML Serializer from PEAR, you can convert the JSON to a PHP object and then the PHP object to XML in two easy steps:

include("XML/Serializer.php");

function json_to_xml($json) {
    $serializer = new XML_Serializer();
    $obj = json_decode($json);

    if ($serializer->serialize($obj)) {
        return $serializer->getSerializedData();
    }
    else {
        return null;
    }
}

It depends on how exactly you want you XML to look like. I would try a combination of json_decode() and the PEAR::XML_Serializer (more info and examples on sitepoint.com).

require_once 'XML/Serializer.php';

$data = json_decode($json, true)

// An array of serializer options
$serializer_options = array (
  'addDecl' => TRUE,
  'encoding' => 'ISO-8859-1',
  'indent' => '  ',
  'rootName' => 'json',
  'mode' => 'simplexml'
); 

$Serializer = &new XML_Serializer($serializer_options);
$status = $Serializer->serialize($data);

if (PEAR::isError($status)) die($status->getMessage());

echo '<pre>';
echo htmlspecialchars($Serializer->getSerializedData());
echo '</pre>';

(Untested code - but you get the idea)

Crack open the JSON with json_decode, and traverse it to generate whatever XML you want.

In case you're wondering, there is no canonical mapping between JSON and XML, so you have to write the XML-generation code yourself, based on the needs of your application.

I combined the two earlier suggestions into:

/**
 * Convert JSON to XML
 * @param string    - json
 * @return string   - XML
 */
function json_to_xml($json)
{
    include_once("XML/Serializer.php");

    $options = array (
      'addDecl' => TRUE,
      'encoding' => 'UTF-8',
      'indent' => '  ',
      'rootName' => 'json',
      'mode' => 'simplexml'
    );

    $serializer = new XML_Serializer($options);
    $obj = json_decode($json);
    if ($serializer->serialize($obj)) {
        return $serializer->getSerializedData();
    } else {
        return null;
    }
}