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

Is there any way to convert json to xml in PHP? I know that xml to json is ve开发者_JAVA百科ry much possible.

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;
    }
}

A native approch might be

function json_to_xml($obj){
  $str = "";
  if(is_null($obj))
    return "<null/>";
  elseif(is_array($obj)) {
      //a list is a hash with 'simple' incremental keys
    $is_list = array_keys($obj) == array_keys(array_values($obj));
    if(!$is_list) {
      $str.= "<hash>";
      foreach($obj as $k=>$v)
        $str.="<item key=\"$k\">".json_to_xml($v)."</item>".CRLF;
      $str .= "</hash>";
    } else {
      $str.= "<list>";
      foreach($obj as $v)
        $str.="<item>".json_to_xml($v)."</item>".CRLF;
      $str .= "</list>";
    }
    return $str;
  } elseif(is_string($obj)) {
    return htmlspecialchars($obj) != $obj ? "<![CDATA[$obj]]>" : $obj;
  } elseif(is_scalar($obj))
    return $obj;
  else
    throw new Exception("Unsupported type $obj");
}

Another option would be to use a JSON streaming parser.

Using a streamer parser would come in handy if you want to bypass the intermediate object graph created by PHP when using json_decode. For instance, when you got a large JSON document and memory is an issue, you could output the XML with XMLWriter directly while reading the document with the streaming parser.

One example would be https://github.com/salsify/jsonstreamingparser

$writer = new XMLWriter;
$xml->openURI('file.xml');
$listener = new JSON2XML($writer); // you need to write the JSON2XML listener
$stream = fopen('doc.json', 'r');
try {
    $parser = new JsonStreamingParser_Parser($stream, $listener);
    $parser->parse();
} catch (Exception $e) {
    fclose($stream);
    throw $e;
}

The JSON2XML Listener would need to implement the Listener interface:

interface JsonStreamingParser_Listener 
{
  public function start_document();
  public function end_document();
  public function start_object();
  public function end_object();
  public function start_array();
  public function end_array();
  public function key($key);
  public function value($value);
}

At runtime, the listener will receive the various events from the parser, e.g. when the parser finds an object, it will send the data to the start_object() method. When it finds an array, it will trigger start_array() and so on. In those methods you'd then delegate the values to the appropriate methods in the XMLWriter, e.g. start_element() and so on.

Disclaimer: I am not affiliated with the author, nor have I used the tool before. I picked this library because the API looked sufficiently simple to illustrate how to use an event based JSON parser.