abp01-plugin-leaflet-plugins-wrapper.php

<?php 
/**
 * Copyright (c) 2014-2021 Alexandru Boia
 *
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *	1. Redistributions of source code must retain the above copyright notice, 
 *		this list of conditions and the following disclaimer.
 *
 * 	2. Redistributions in binary form must reproduce the above copyright notice, 
 *		this list of conditions and the following disclaimer in the documentation 
 *		and/or other materials provided with the distribution.
 *
 *	3. Neither the name of the copyright holder nor the names of its contributors 
 *		may be used to endorse or promote products derived from this software without 
 *		specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY 
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * This script serves as a handler used to wrap leafleft plug-ins 
 *  with a self-executing function
 *  that provides the correct value for the L global javascript variable.
 * The value is taken from the global variable populated by the plug-in
 *  with its own leaflet instance,
 *  whose provided by the ABP01_WRAPPED_LEAFLET_CONTEXT constant.
 * 
 * Thus, the content served by this handler would look something like:
 *      (function(L) { 
 *          ...plug-in script content... 
 *      })(window.abp01Leaflet);
 * 
 * @see ABP01_WRAPPED_LEAFLET_CONTEXT
 * 
 * @package WP-Trip-Summary
 */

error_reporting(0);

if (!defined('ABSPATH')) {
	define('ABSPATH', dirname(dirname(dirname(__DIR__))) . '/');
}

if (!defined('WP_DEBUG')) {
    define('WP_DEBUG', false);
}

require_once __DIR__ . '/abp01-plugin-wpshim.php';
require_once __DIR__ . '/abp01-plugin-header.php';

/**
 * Attempts to increase execution limits: time and memory.
 * Additionally, if the xdebug extension is installed, 
 *  the xdebug.max_nesting_level option is also increased
 * 
 * @see ABP01_WRAPPED_SCRIPT_MAX_EXECUTION_TIME_MINUTES
 * @see ABP01_WRAPPED_SCRIPT_MAX_MEMORY
 * 
 * @return void
 */
function abp01_wrapper_increase_limits() {
    if (function_exists('set_time_limit')) {
		@set_time_limit(ABP01_WRAPPED_SCRIPT_MAX_EXECUTION_TIME_MINUTES * 60);
	}
	if (function_exists('ini_set')) {
		@ini_set('memory_limit', ABP01_WRAPPED_SCRIPT_MAX_MEMORY);
		//If the xdebubg extension is loaded, 
		//	attempt to increase the max_nesting_level setting, 
		//	since (as is the case with large GPX files) 
		//	the simplify algorithm will fail due to its recursive nature 
		//	reaching that limit quickly if it's set too low
		if (extension_loaded('xdebug')) {
			@ini_set('xdebug.max_nesting_level', 1000000);
		}
	}
}

/**
 * Determine which script should be wrapped.
 * First looks at the 'load' URL parameter. 
 *  If it's set, its value is returned.
 *  If not, the path component of the REQUEST_URI server var is returned.
 * 
 * @return string The relative path to WP's root directory of the script that must be wrapped
 */
function abp01_wrapper_get_file_to_wrap() {
    $load = !empty($_GET['load']) 
        ? trim(strip_tags($_GET['load']))
        : null;

    $requestUri = isset($_SERVER['REQUEST_URI']) 
        ? $_SERVER['REQUEST_URI']
        : null;

    $uri = parse_url($requestUri);
    if (!empty($load)) {
        //We're expecting 'load' to be relative to the plug-in's own root directory
        $load = preg_match('/' . preg_quote(basename(__FILE__)) . '$/i', $uri['path']) 
            ? '/wp-content/plugins/' . ABP01_PLUGIN_ROOT_NAME . '/' . preg_replace('/[^a-zA-Z0-9\/.\-_]/', '', $load) 
            : null;
    } else {
        $load = $uri['path'];
    }

    return $load;
}

function abp01_wrapper_get_script_etag() {
    $version = isset($_GET['ver']) 
        ? $_GET['ver'] 
        : null;

    $etag = ABP01_VERSION;
    if (!empty($version)) {
        $version = preg_replace('/[^a-zA-Z0-9.\-_]/', '', $version);
        $etag = $version . '-' . $etag;
    }

    return $etag;
}

/**
 * Tests whether the given requrest URI path
 *  matches an allowed pattern, to avoid serving only some files we deem fit
 * @return boolean True if allowed, false otherwise
 */
function abp01_wrapper_should_serve_script($requestUriPath) {
    return preg_match('/^(\/wp-content\/plugins\/)([^\/]+)(\/media\/js\/3rdParty\/leaflet-plugins\/)(.*)\/([^\/]+)\.js(\?ver=([a-zA-Z0-9.]+))?$/i', 
        $requestUriPath);
}

/**
 * Locate the file and return its absolute path
 * @return string The absolute file path
 */
function abp01_wrapper_locate_file_from_uri($requestUriPath) {
    if (!empty($requestUriPath)) {
        return ABSPATH . $requestUriPath;
    } else {
        return null;
    }
}

/**
 * Fetches the contents of the script located at the given path
 *  and wraps it in a self executing function that ensures "L" points
 *  to the correct Leaflet version
 * 
 * @param string $filePath The absolute path of the script that should be processed
 * @return string The processed content
 */
function abp01_wrapper_process_script($filePath) {
    $bom = pack('H*','EFBBBF');
    
    $contents = @file_get_contents($filePath);
    $contents = trim(preg_replace("/^$bom/", '', $contents));

    return (
        '(function (L) {' .  PHP_EOL .
            $contents  . PHP_EOL .
        '})(window.' . ABP01_WRAPPED_LEAFLET_CONTEXT . ');'
    );
}

/**
 * Run the entire script wrapping process
 * @return void
 */
function abp01_wrapper_serve_script() {
    $content = null;
    $contentLength = 0;
    $protocol = $_SERVER['SERVER_PROTOCOL'];

    if (!in_array($protocol, array('HTTP/1.1', 'HTTP/2', 'HTTP/2.0'))) {
        $protocol = 'HTTP/1.0';
    }

    //See if there's anything to process
    $requestUri = abp01_wrapper_get_file_to_wrap();
    if (!empty($requestUri) && abp01_wrapper_should_serve_script($requestUri)) {
        //Locate script file and see if it's readable
        $wrapFilePath = abp01_wrapper_locate_file_from_uri($requestUri);
        if (!empty($wrapFilePath) && is_readable($wrapFilePath)) {
            $etag = abp01_wrapper_get_script_etag();

            if (isset($_SERVER['HTTP_IF_NONE_MATCH'] ) && stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) === $etag) {
                header($protocol . ' 304 Not Modified');
                die;
            }

            //Process content
            $content = abp01_wrapper_process_script($wrapFilePath);
            if (function_exists('mb_strlen')) {
                $contentLength = mb_strlen($content);
            } else {
                $contentLength = strlen($content);
            }
        }
    }

    if (!empty($content)) {
        //Spit it out
        header('Etag: ' . $etag);
        header('Content-Type: application/javascript; charset=UTF-8');
        header('Content-Length: ' . $contentLength);
        header('Expires: ' . gmdate('D, d M Y H:i:s', time() + ABP01_WRAPPED_SCRIPT_MAX_AGE) . ' GMT');
        header('Cache-Control: public, max-age=' . ABP01_WRAPPED_SCRIPT_MAX_AGE );
        echo $content;
    } else {
        header($protocol . ' 404 Not Found');
    }

    //We done
    die;
}

abp01_wrapper_increase_limits();
abp01_wrapper_serve_script();