JSON to XML php script

$array = json_decode ($someJsonString, true);

$xml = new SimpleXMLElement('<root/>');
$this->arrayToXml($array, $xml);

/**
 * Convert an array to XML
 * @param array $array
 * @param SimpleXMLElement $xml
 */
function arrayToXml($array, &$xml){
    foreach ($array as $key => $value) {
        if(is_array($value)){
            if(is_int($key)){
                $key = "e";
            }
            $label = $xml->addChild($key);
            $this->arrayToXml($value, $label);
        }
        else {
            $xml->addChild($key, $value);
        }
    }
}

<?php

// $url will contain the API endpoint
$url = "https://app.teamleader.eu/api/helloWorld.php";

// $fields contains all the fields that will be POSTed
$fields = array(  
	"api_group"=>("YOUR_API_GROUP"),
	"api_secret"=>("YOUR_API_SECRET")
);

// Make the POST request using Curl
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, true);   
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);

// Decode and display the output
$api_output =  curl_exec($ch);
$json_output = json_decode($api_output);
$output = $json_output?$json_output:$api_output;

// Clean up
curl_close($ch);

?>