ap_form_handler.php

<?php
function sendRequest($xml)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, "http://manage.encoding.com/");
    curl_setopt($ch, CURLOPT_POSTFIELDS, "xml=" . urlencode($xml));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    return curl_exec($ch);
}   

// Begin processing User's POST
if(!empty($_POST['source']))
{
    // Preparing XML request
    
    // Main fields
    $req = new SimpleXMLElement('<?xml version="1.0"?><query></query>');
    $req->addChild('userid', MY_ID);
    $req->addChild('userkey', MY_KEY);
    $req->addChild('action', 'AddMedia');
    $req->addChild('source', $_POST['source']);
    
    $formatNode = $req->addChild('format');
    // Format fields
    foreach($_POST['format'] as $property => $value)
    {
        if ($value !== '')
        $formatNode->addChild($property, $value);
    }
    
    // Sending API request
    $res = sendRequest($req->asXML());
    
    try
    {
        // Creating new object from response XML
        $response = new SimpleXMLElement($res);
        
        // If there are any errors, set error message
        if(isset($response->errors[0]->error[0])) {
            $error = $response->errors[0]->error[0] . '';
        }
        else
        if ($response->message[0]) {
            // If message received, set OK message
            $message = $response->message[0] . '';
        }
    }
    catch(Exception $e)
    {
        // If wrong XML response received
        $error = $e->getMessage();
    }
    
    // Displaying error if any
    if (!empty($error)) {
        echo '<div class="error">' . htmlspecialchars($error) . '</div>';
    }
    
    // Displaying message
    if (!empty($message)) {
        echo '<div class="message">' . htmlspecialchars($message) . '</div>';
    }
    exit;
}