Core/Modules/api/class.rest.php

<?php
/**
 * FuzeWorks.
 *
 * The FuzeWorks MVC PHP FrameWork
 *
 * Copyright (C) 2015   TechFuze
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @author    TechFuze
 * @copyright Copyright (c) 2013 - 2016, Techfuze. (http://techfuze.net)
 * @copyright Copyright (c) 1996 - 2015, Free Software Foundation, Inc. (http://www.fsf.org/)
 * @license   http://opensource.org/licenses/GPL-3.0 GPLv3 License
 *
 * @link  http://fuzeworks.techfuze.net
 * @since Version 0.0.1
 *
 * @version Version 0.0.1
 */

namespace Module\Api;

use FuzeWorks\Layout;

/**
 * RestAPI class for creating API's out of modules or contrllers.
 *
 * Extend a Controller with this class, and be sure to return the data from methods of your controller.
 * This data will be parsed by this class and returned as valid JSON data.
 * The necessity of API keys can be configured in the controller by settings $this->requireApiKey = false;
 *
 * @author    Abel Hoogeveen <abel@techfuze.net>
 * @copyright Copyright (c) 2013 - 2016, Techfuze. (http://techfuze.net)
 */
abstract class RestAPI
{
    /**
     * Property: method
     * The HTTP method this request was made in, either GET, POST, PUT or DELETE.
     */
    protected $method = '';
    /**
     * Property: endpoint
     * The Model requested in the URI. eg: /files.
     */
    protected $endpoint = '';
    /**
     * Property: verb
     * An optional additional descriptor about the endpoint, used for things that can
     * not be handled by the basic methods. eg: /files/process.
     */
    protected $verb = '';
    /**
     * Property: args
     * Any additional URI components after the endpoint and verb have been removed, in our
     * case, an integer ID for the resource. eg: /<endpoint>/<verb>/<arg0>/<arg1>
     * or /<endpoint>/<arg0>.
     */
    protected $args = array();
    /**
     * Property: file
     * Stores the input of the PUT request.
     */
    protected $file = null;

    /**
     * Whether API authentication is needed before interacting with the API.
     */
    protected $requireApiKey = true;

    /**
     * Constructor: __construct
     * Allow for CORS, assemble and pre-process the data.
     */
    public function __construct($request)
    {
        header('Access-Control-Allow-Orgin: *');
        header('Access-Control-Allow-Methods: *');
        header('Content-Type: application/json');

        // Return layout data as string
        Layout::setEngine('JSON');
        Layout::returnAsString(false);

        $this->args = explode('/', rtrim($request, '/'));
        $this->endpoint = array_shift($this->args);
        if (array_key_exists(0, $this->args) && !is_numeric($this->args[0])) {
            $this->verb = array_shift($this->args);
        }

        $this->method = $_SERVER['REQUEST_METHOD'];
        if ($this->method == 'POST' && array_key_exists('HTTP_X_HTTP_METHOD', $_SERVER)) {
            if ($_SERVER['HTTP_X_HTTP_METHOD'] == 'DELETE') {
                $this->method = 'DELETE';
            } elseif ($_SERVER['HTTP_X_HTTP_METHOD'] == 'PUT') {
                $this->method = 'PUT';
            } else {
                throw new Exception('Unexpected Header');
            }
        }

        switch ($this->method) {
            case 'DELETE':
            case 'POST':
                $this->request = $this->_cleanInputs($_POST);
                break;
            case 'GET':
                $this->request = $this->_cleanInputs($_GET);
                break;
            case 'PUT':
                $this->request = $this->_cleanInputs($_GET);
                $this->file = file_get_contents('php://input');
                break;
            default:
                $this->_response('Invalid Method', 405);
                break;
        }

        // And afterwards process the data
        echo $this->processAPI();

        // Halter for when the RestApi is used by a controller
        $this->halt = true;
        Layout::reset();
    }

    /**
     * Process an API request when retrieving.
     *
     * @return string JSON encoded response
     */
    public function processAPI()
    {
        if (method_exists($this, $this->endpoint)) {
            return $this->_response($this->{$this->endpoint}($this->args));
        }

        return $this->_response("No Endpoint: $this->endpoint", 404);
    }

    private function _response($data, $status = 200)
    {
        header('HTTP/1.1 '.$status.' '.$this->_requestStatus($status));

        return json_encode($data);
    }

    private function _cleanInputs($data)
    {
        $clean_input = array();
        if (is_array($data)) {
            foreach ($data as $k => $v) {
                $clean_input[$k] = $this->_cleanInputs($v);
            }
        } else {
            $clean_input = trim(strip_tags($data));
        }

        return $clean_input;
    }

    private function _requestStatus($code)
    {
        $status = array(
            200 => 'OK',
            404 => 'Not Found',
            405 => 'Method Not Allowed',
            500 => 'Internal Server Error',
        );

        return ($status[$code]) ? $status[$code] : $status[500];
    }
}