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');
}