Full Example
------------
Below are the full example to demonstrate the basic structure of PHP web services.

Assume you have the following file in ``./includes/User.php``::

    <?php

    class User {
        public function do_GET($params) {
            $response = array(
                'url' => $_SERVER['REQUEST_URI'],
            );
            print_r($params);
            echo json_encode($response);
        }

        public function do_POST($params) {
            $data = file_get_contents('php://input');
            $data_json = json_decode($data, true);
            print_r($params);
            echo json_encode($data_json);
        }
    }

And this is ``index.php``::

    <?php

    $api_credentials = array(
        'user1' => 'abc123',
        'user2' => 'abcxyz'
    );

    $resources = array(
        'User',
    );

    include 'includes/User.php';

    /***********************
    Authentication
    ************************/
    if (!isset($_SERVER['PHP_AUTH_USER'])) {
        header('WWW-Authenticate: Basic realm="My API"');
        header('HTTP/1.1 401 Unauthorized');
        exit;
    } else {
        $username = $_SERVER['PHP_AUTH_USER'];
        $password = $_SERVER['PHP_AUTH_PW'];

        if (!array_key_exists($username, $api_credentials)) {
            header('HTTP/1.1 403 Forbidden');
            exit;
        }
        if ($password != $api_credentials[$username]) {
            header('HTTP/1.1 403 Forbidden');
            exit;
        }
    }

    /******************
    Finding Resources
    ******************/
    $paths = explode('/', $_SERVER['REQUEST_URI']);
    array_shift($paths);
    $resource = array_shift($paths);
    if (!in_array($resource, $resources)) {
        header('HTTP/1.1 404 Not Found');
        exit;
    }

    /****************
    Operations
    ****************/
    $method = $_SERVER['REQUEST_METHOD'];
    $resource_instance = new $resource;
    $resource_method = 'do_' . $method;
    if (method_exists($resource_instance, $resource_method)) {
        call_user_func(array($resource_instance, $resource_method), $paths);
    }
    else {
        header('HTTP/1.1 405 Method Not Allowed');
        header('Allow: GET, POST');
    }