<?php 
/** 
 * Copyright 2016 Facebook, Inc. 
 * 
 * You are hereby granted a non-exclusive, worldwide, royalty-free license to 
 * use, copy, modify, and distribute this software in source code or binary 
 * form for use in connection with the web services and APIs provided by 
 * Facebook. 
 * 
 * As with any software that integrates with the Facebook platform, your use 
 * of this software is subject to the Facebook Developer Principles and 
 * Policies [http://developers.facebook.com/policy/]. This copyright notice 
 * shall be included in all copies or substantial portions of the software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE. 
 * 
 */ 
 
/** 
 * You only need this file if you are not using composer. 
 * Why are you not using composer? 
 * https://getcomposer.org/ 
 */ 
 
if (version_compare(PHP_VERSION, '5.4.0', '<')) { 
    throw new Exception('The Facebook SDK requires PHP version 5.4 or higher.'); 
} 
 
/** 
 * Register the autoloader for the Facebook SDK classes. 
 * 
 * Based off the official PSR-4 autoloader example found here: 
 * https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader-examples.md 
 * 
 * @param string $class The fully-qualified class name. 
 * 
 * @return void 
 */ 
spl_autoload_register(function ($class) { 
    // project-specific namespace prefix 
    $prefix = 'Facebook\\'; 
 
    // For backwards compatibility 
    $customBaseDir = ''; 
    // @todo v6: Remove support for 'FACEBOOK_SDK_V4_SRC_DIR' 
    if (defined('FACEBOOK_SDK_V4_SRC_DIR')) { 
        $customBaseDir = FACEBOOK_SDK_V4_SRC_DIR; 
    } elseif (defined('FACEBOOK_SDK_SRC_DIR')) { 
        $customBaseDir = FACEBOOK_SDK_SRC_DIR; 
    } 
    // base directory for the namespace prefix 
    $baseDir = $customBaseDir ?: __DIR__ . '/'; 
 
    // does the class use the namespace prefix? 
    $len = strlen($prefix); 
    if (strncmp($prefix, $class, $len) !== 0) { 
        // no, move to the next registered autoloader 
        return; 
    } 
 
    // get the relative class name 
    $relativeClass = substr($class, $len); 
 
    // replace the namespace prefix with the base directory, replace namespace 
    // separators with directory separators in the relative class name, append 
    // with .php 
    $file = rtrim($baseDir, '/') . '/' . str_replace('\\', '/', $relativeClass) . '.php'; 
 
    // if the file exists, require it 
    if (file_exists($file)) { 
        require $file; 
    } 
}); 
 
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