PHP Object as XML Document

Question

What is the best way to take a given PHP object and serialize it as XML? I am looking at simple_xml and I have used it to parse XML into objects, but it isn't clear to me how it works the other way around.

Answer 1

Use a dom function to do it: http://www.php.net/manual/en/function.dom-import-simplexml.php

Import the SimpleXML object and then save. The above link contains an example. :)

In a nutshell:

<?php
$array = array('hello' => 'world', 'good' => 'morning');

$xml = simplexml_load_string("<?xml version='1.0' encoding='utf-8'?><foo />");
foreach ($array as $k=>$v) {
  $xml->addChild($k, $v);
}
?>

Answer 2

Well, while a little dirty, you could always run a loop on the object's properties...

foreach($obj as $key => $val){
  $_xml .= "<".$key.">".$val."</".$key">\n";
}

Using fopen/fwrite/fclose you could generate an XML doc with the $_xml variable as content. It's ugly, but it would work.

Answer 3

take a look at PEAR's XML_Serializer package. I've used it with pretty good results. You can feed it arrays, objects etc and it will turn them into XML. It also has a bunch of options like picking the name of the root node etc.

Should do the trick

Answer 4

I didn't do any XML <=> PHP-Objects conversion but if you just want a way to serialize your php obejcts then it is very simple, you can use php built-in json_encode() and json_decode() these functions take care of everything and your php objects are serialized as JSON.

These functions are available as of PHP 5.2.0 and above, if you use an older version then use PECL json:1.2.0-1.2.1

http://www.php.net/json_encode

Answer 5

use WDDX: http://uk.php.net/manual/en/wddx.examples.php

(if this extension is installed)

it's dedicated to that:

http://www.openwddx.org/

Answer 6

not quite an answer to the original question, but the way i solved my problem with this was by declaring my object as:

$root = '<?xml version="1.0" encoding="UTF-8"?><Activities/>';
$object = new simpleXMLElement($root); 

as opposed to:

$object = new stdClass;

before i started adding any values!

Answer 7

I'd agree with using PEAR's XML_Serializer, but if you want something simple that supports objects/arrays that have properties nested, you can use this.

class XMLSerializer {

    // functions adopted from http://www.sean-barton.co.uk/2009/03/turning-an-array-or-object-into-xml-using-php/

    public static function generateValidXmlFromObj(stdClass $obj, $node_block='nodes', $node_name='node') {
        $arr = get_object_vars($obj);
        return self::generateValidXmlFromArray($arr, $node_block, $node_name);
    }

    public static function generateValidXmlFromArray($array, $node_block='nodes', $node_name='node') {
        $xml = '<?xml version="1.0" encoding="UTF-8" ?>';

        $xml .= '<' . $node_block . '>';
        $xml .= self::generateXmlFromArray($array, $node_name);
        $xml .= '</' . $node_block . '>';

        return $xml;
    }

    private static function generateXmlFromArray($array, $node_name) {
        $xml = '';

        if (is_array($array) || is_object($array)) {
            foreach ($array as $key=>$value) {
                if (is_numeric($key)) {
                    $key = $node_name;
                }

                $xml .= '<' . $key . '>' . self::generateXmlFromArray($value, $node_name) . '</' . $key . '>';
            }
        } else {
            $xml = htmlspecialchars($array, ENT_QUOTES);
        }

        return $xml;
    }

}

Answer 8

There is Another answer that talks about usage of WDDX. Bit its Voted Down too !! Is there any known problem with WDDX ?? I couldn't understand the reason behind voting down.