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+<?php
+
+if (!function_exists('curl_init')) {
+ throw new Exception('Facebook needs the CURL PHP extension.');
+}
+if (!function_exists('json_decode')) {
+ throw new Exception('Facebook needs the JSON PHP extension.');
+}
+
+/**
+ * Thrown when an API call returns an exception.
+ *
+ * @author Naitik Shah <naitik@facebook.com>
+ */
+class FacebookApiException extends Exception
+{
+ /**
+ * The result from the API server that represents the exception information.
+ */
+ protected $result;
+
+ /**
+ * Make a new API Exception with the given result.
+ *
+ * @param Array $result the result from the API server
+ */
+ public function __construct($result) {
+ $this->result = $result;
+
+ $code = isset($result['error_code']) ? $result['error_code'] : 0;
+
+ if (isset($result['error_description'])) {
+ // OAuth 2.0 Draft 10 style
+ $msg = $result['error_description'];
+ } else if (isset($result['error']) && is_array($result['error'])) {
+ // OAuth 2.0 Draft 00 style
+ $msg = $result['error']['message'];
+ } else if (isset($result['error_msg'])) {
+ // Rest server style
+ $msg = $result['error_msg'];
+ } else {
+ $msg = 'Unknown Error. Check getResult()';
+ }
+
+ parent::__construct($msg, $code);
+ }
+
+ /**
+ * Return the associated result object returned by the API server.
+ *
+ * @returns Array the result from the API server
+ */
+ public function getResult() {
+ return $this->result;
+ }
+
+ /**
+ * Returns the associated type for the error. This will default to
+ * 'Exception' when a type is not available.
+ *
+ * @return String
+ */
+ public function getType() {
+ if (isset($this->result['error'])) {
+ $error = $this->result['error'];
+ if (is_string($error)) {
+ // OAuth 2.0 Draft 10 style
+ return $error;
+ } else if (is_array($error)) {
+ // OAuth 2.0 Draft 00 style
+ if (isset($error['type'])) {
+ return $error['type'];
+ }
+ }
+ }
+ return 'Exception';
+ }
+
+ /**
+ * To make debugging easier.
+ *
+ * @returns String the string representation of the error
+ */
+ public function __toString() {
+ $str = $this->getType() . ': ';
+ if ($this->code != 0) {
+ $str .= $this->code . ': ';
+ }
+ return $str . $this->message;
+ }
+}
+
+/**
+ * Provides access to the Facebook Platform.
+ *
+ * @author Naitik Shah <naitik@facebook.com>
+ */
+class Facebook
+{
+ /**
+ * Version.
+ */
+ const VERSION = '2.1.2';
+
+ /**
+ * Default options for curl.
+ */
+ public static $CURL_OPTS = array(
+ CURLOPT_CONNECTTIMEOUT => 10,
+ CURLOPT_RETURNTRANSFER => true,
+ CURLOPT_TIMEOUT => 60,
+ CURLOPT_USERAGENT => 'facebook-php-2.0',
+ );
+
+ /**
+ * List of query parameters that get automatically dropped when rebuilding
+ * the current URL.
+ */
+ protected static $DROP_QUERY_PARAMS = array(
+ 'session',
+ 'signed_request',
+ );
+
+ /**
+ * Maps aliases to Facebook domains.
+ */
+ public static $DOMAIN_MAP = array(
+ 'api' => 'https://api.facebook.com/',
+ 'api_read' => 'https://api-read.facebook.com/',
+ 'graph' => 'https://graph.facebook.com/',
+ 'www' => 'https://www.facebook.com/',
+ );
+
+ /**
+ * The Application ID.
+ */
+ protected $appId;
+
+ /**
+ * The Application API Secret.
+ */
+ protected $apiSecret;
+
+ /**
+ * The active user session, if one is available.
+ */
+ protected $session;
+
+ /**
+ * The data from the signed_request token.
+ */
+ protected $signedRequest;
+
+ /**
+ * Indicates that we already loaded the session as best as we could.
+ */
+ protected $sessionLoaded = false;
+
+ /**
+ * Indicates if Cookie support should be enabled.
+ */
+ protected $cookieSupport = false;
+
+ /**
+ * Base domain for the Cookie.
+ */
+ protected $baseDomain = '';
+
+ /**
+ * Indicates if the CURL based @ syntax for file uploads is enabled.
+ */
+ protected $fileUploadSupport = false;
+
+ /**
+ * Initialize a Facebook Application.
+ *
+ * The configuration:
+ * - appId: the application ID
+ * - secret: the application secret
+ * - cookie: (optional) boolean true to enable cookie support
+ * - domain: (optional) domain for the cookie
+ * - fileUpload: (optional) boolean indicating if file uploads are enabled
+ *
+ * @param Array $config the application configuration
+ */
+ public function __construct($config) {
+ $this->setAppId($config['appId']);
+ $this->setApiSecret($config['secret']);
+ if (isset($config['cookie'])) {
+ $this->setCookieSupport($config['cookie']);
+ }
+ if (isset($config['domain'])) {
+ $this->setBaseDomain($config['domain']);
+ }
+ if (isset($config['fileUpload'])) {
+ $this->setFileUploadSupport($config['fileUpload']);
+ }
+ }
+
+ /**
+ * Set the Application ID.
+ *
+ * @param String $appId the Application ID
+ */
+ public function setAppId($appId) {
+ $this->appId = $appId;
+ return $this;
+ }
+
+ /**
+ * Get the Application ID.
+ *
+ * @return String the Application ID
+ */
+ public function getAppId() {
+ return $this->appId;
+ }
+
+ /**
+ * Set the API Secret.
+ *
+ * @param String $appId the API Secret
+ */
+ public function setApiSecret($apiSecret) {
+ $this->apiSecret = $apiSecret;
+ return $this;
+ }
+
+ /**
+ * Get the API Secret.
+ *
+ * @return String the API Secret
+ */
+ public function getApiSecret() {
+ return $this->apiSecret;
+ }
+
+ /**
+ * Set the Cookie Support status.
+ *
+ * @param Boolean $cookieSupport the Cookie Support status
+ */
+ public function setCookieSupport($cookieSupport) {
+ $this->cookieSupport = $cookieSupport;
+ return $this;
+ }
+
+ /**
+ * Get the Cookie Support status.
+ *
+ * @return Boolean the Cookie Support status
+ */
+ public function useCookieSupport() {
+ return $this->cookieSupport;
+ }
+
+ /**
+ * Set the base domain for the Cookie.
+ *
+ * @param String $domain the base domain
+ */
+ public function setBaseDomain($domain) {
+ $this->baseDomain = $domain;
+ return $this;
+ }
+
+ /**
+ * Get the base domain for the Cookie.
+ *
+ * @return String the base domain
+ */
+ public function getBaseDomain() {
+ return $this->baseDomain;
+ }
+
+ /**
+ * Set the file upload support status.
+ *
+ * @param String $domain the base domain
+ */
+ public function setFileUploadSupport($fileUploadSupport) {
+ $this->fileUploadSupport = $fileUploadSupport;
+ return $this;
+ }
+
+ /**
+ * Get the file upload support status.
+ *
+ * @return String the base domain
+ */
+ public function useFileUploadSupport() {
+ return $this->fileUploadSupport;
+ }
+
+ /**
+ * Get the data from a signed_request token
+ *
+ * @return String the base domain
+ */
+ public function getSignedRequest() {
+ if (!$this->signedRequest) {
+ if (isset($_REQUEST['signed_request'])) {
+ $this->signedRequest = $this->parseSignedRequest(
+ $_REQUEST['signed_request']);
+ }
+ }
+ return $this->signedRequest;
+ }
+
+ /**
+ * Set the Session.
+ *
+ * @param Array $session the session
+ * @param Boolean $write_cookie indicate if a cookie should be written. this
+ * value is ignored if cookie support has been disabled.
+ */
+ public function setSession($session=null, $write_cookie=true) {
+ $session = $this->validateSessionObject($session);
+ $this->sessionLoaded = true;
+ $this->session = $session;
+ if ($write_cookie) {
+ $this->setCookieFromSession($session);
+ }
+ return $this;
+ }
+
+ /**
+ * Get the session object. This will automatically look for a signed session
+ * sent via the signed_request, Cookie or Query Parameters if needed.
+ *
+ * @return Array the session
+ */
+ public function getSession() {
+ if (!$this->sessionLoaded) {
+ $session = null;
+ $write_cookie = true;
+
+ // try loading session from signed_request in $_REQUEST
+ $signedRequest = $this->getSignedRequest();
+ if ($signedRequest) {
+ // sig is good, use the signedRequest
+ $session = $this->createSessionFromSignedRequest($signedRequest);
+ }
+
+ // try loading session from $_REQUEST
+ if (!$session && isset($_REQUEST['session'])) {
+ $session = json_decode(
+ get_magic_quotes_gpc()
+ ? stripslashes($_REQUEST['session'])
+ : $_REQUEST['session'],
+ true
+ );
+ $session = $this->validateSessionObject($session);
+ }
+
+ // try loading session from cookie if necessary
+ if (!$session && $this->useCookieSupport()) {
+ $cookieName = $this->getSessionCookieName();
+ if (isset($_COOKIE[$cookieName])) {
+ $session = array();
+ parse_str(trim(
+ get_magic_quotes_gpc()
+ ? stripslashes($_COOKIE[$cookieName])
+ : $_COOKIE[$cookieName],
+ '"'
+ ), $session);
+ $session = $this->validateSessionObject($session);
+ // write only if we need to delete a invalid session cookie
+ $write_cookie = empty($session);
+ }
+ }
+
+ $this->setSession($session, $write_cookie);
+ }
+
+ return $this->session;
+ }
+
+ /**
+ * Get the UID from the session.
+ *
+ * @return String the UID if available
+ */
+ public function getUser() {
+ $session = $this->getSession();
+ return $session ? $session['uid'] : null;
+ }
+
+ /**
+ * Gets a OAuth access token.
+ *
+ * @return String the access token
+ */
+ public function getAccessToken() {
+ $session = $this->getSession();
+ // either user session signed, or app signed
+ if ($session) {
+ return $session['access_token'];
+ } else {
+ return $this->getAppId() .'|'. $this->getApiSecret();
+ }
+ }
+
+ /**
+ * Get a Login URL for use with redirects. By default, full page redirect is
+ * assumed. If you are using the generated URL with a window.open() call in
+ * JavaScript, you can pass in display=popup as part of the $params.
+ *
+ * The parameters:
+ * - next: the url to go to after a successful login
+ * - cancel_url: the url to go to after the user cancels
+ * - req_perms: comma separated list of requested extended perms
+ * - display: can be "page" (default, full page) or "popup"
+ *
+ * @param Array $params provide custom parameters
+ * @return String the URL for the login flow
+ */
+ public function getLoginUrl($params=array()) {
+ $currentUrl = $this->getCurrentUrl();
+ return $this->getUrl(
+ 'www',
+ 'login.php',
+ array_merge(array(
+ 'api_key' => $this->getAppId(),
+ 'cancel_url' => $currentUrl,
+ 'display' => 'page',
+ 'fbconnect' => 1,
+ 'next' => $currentUrl,
+ 'return_session' => 1,
+ 'session_version' => 3,
+ 'v' => '1.0',
+ ), $params)
+ );
+ }
+
+ /**
+ * Get a Logout URL suitable for use with redirects.
+ *
+ * The parameters:
+ * - next: the url to go to after a successful logout
+ *
+ * @param Array $params provide custom parameters
+ * @return String the URL for the logout flow
+ */
+ public function getLogoutUrl($params=array()) {
+ return $this->getUrl(
+ 'www',
+ 'logout.php',
+ array_merge(array(
+ 'next' => $this->getCurrentUrl(),
+ 'access_token' => $this->getAccessToken(),
+ ), $params)
+ );
+ }
+
+ /**
+ * Get a login status URL to fetch the status from facebook.
+ *
+ * The parameters:
+ * - ok_session: the URL to go to if a session is found
+ * - no_session: the URL to go to if the user is not connected
+ * - no_user: the URL to go to if the user is not signed into facebook
+ *
+ * @param Array $params provide custom parameters
+ * @return String the URL for the logout flow
+ */
+ public function getLoginStatusUrl($params=array()) {
+ return $this->getUrl(
+ 'www',
+ 'extern/login_status.php',
+ array_merge(array(
+ 'api_key' => $this->getAppId(),
+ 'no_session' => $this->getCurrentUrl(),
+ 'no_user' => $this->getCurrentUrl(),
+ 'ok_session' => $this->getCurrentUrl(),
+ 'session_version' => 3,
+ ), $params)
+ );
+ }
+
+ /**
+ * Make an API call.
+ *
+ * @param Array $params the API call parameters
+ * @return the decoded response
+ */
+ public function api(/* polymorphic */) {
+ $args = func_get_args();
+ if (is_array($args[0])) {
+ return $this->_restserver($args[0]);
+ } else {
+ return call_user_func_array(array($this, '_graph'), $args);
+ }
+ }
+
+ /**
+ * Invoke the old restserver.php endpoint.
+ *
+ * @param Array $params method call object
+ * @return the decoded response object
+ * @throws FacebookApiException
+ */
+ protected function _restserver($params) {
+ // generic application level parameters
+ $params['api_key'] = $this->getAppId();
+ $params['format'] = 'json-strings';
+
+ $result = json_decode($this->_oauthRequest(
+ $this->getApiUrl($params['method']),
+ $params
+ ), true);
+
+ // results are returned, errors are thrown
+ if (is_array($result) && isset($result['error_code'])) {
+ throw new FacebookApiException($result);
+ }
+ return $result;
+ }
+
+ /**
+ * Invoke the Graph API.
+ *
+ * @param String $path the path (required)
+ * @param String $method the http method (default 'GET')
+ * @param Array $params the query/post data
+ * @return the decoded response object
+ * @throws FacebookApiException
+ */
+ protected function _graph($path, $method='GET', $params=array()) {
+ if (is_array($method) && empty($params)) {
+ $params = $method;
+ $method = 'GET';
+ }
+ $params['method'] = $method; // method override as we always do a POST
+
+ $result = json_decode($this->_oauthRequest(
+ $this->getUrl('graph', $path),
+ $params
+ ), true);
+
+ // results are returned, errors are thrown
+ if (is_array($result) && isset($result['error'])) {
+ $e = new FacebookApiException($result);
+ switch ($e->getType()) {
+ // OAuth 2.0 Draft 00 style
+ case 'OAuthException':
+ // OAuth 2.0 Draft 10 style
+ case 'invalid_token':
+ $this->setSession(null);
+ }
+ throw $e;
+ }
+ return $result;
+ }
+
+ /**
+ * Make a OAuth Request
+ *
+ * @param String $path the path (required)
+ * @param Array $params the query/post data
+ * @return the decoded response object
+ * @throws FacebookApiException
+ */
+ protected function _oauthRequest($url, $params) {
+ if (!isset($params['access_token'])) {
+ $params['access_token'] = $this->getAccessToken();
+ }
+
+ // json_encode all params values that are not strings
+ foreach ($params as $key => $value) {
+ if (!is_string($value)) {
+ $params[$key] = json_encode($value);
+ }
+ }
+ return $this->makeRequest($url, $params);
+ }
+
+ /**
+ * Makes an HTTP request. This method can be overriden by subclasses if
+ * developers want to do fancier things or use something other than curl to
+ * make the request.
+ *
+ * @param String $url the URL to make the request to
+ * @param Array $params the parameters to use for the POST body
+ * @param CurlHandler $ch optional initialized curl handle
+ * @return String the response text
+ */
+ protected function makeRequest($url, $params, $ch=null) {
+ if (!$ch) {
+ $ch = curl_init();
+ }
+
+ $opts = self::$CURL_OPTS;
+ if ($this->useFileUploadSupport()) {
+ $opts[CURLOPT_POSTFIELDS] = $params;
+ } else {
+ $opts[CURLOPT_POSTFIELDS] = http_build_query($params, null, '&');
+ }
+ $opts[CURLOPT_URL] = $url;
+
+ // disable the 'Expect: 100-continue' behaviour. This causes CURL to wait
+ // for 2 seconds if the server does not support this header.
+ if (isset($opts[CURLOPT_HTTPHEADER])) {
+ $existing_headers = $opts[CURLOPT_HTTPHEADER];
+ $existing_headers[] = 'Expect:';
+ $opts[CURLOPT_HTTPHEADER] = $existing_headers;
+ } else {
+ $opts[CURLOPT_HTTPHEADER] = array('Expect:');
+ }
+
+ curl_setopt_array($ch, $opts);
+ $result = curl_exec($ch);
+ if ($result === false) {
+ $e = new FacebookApiException(array(
+ 'error_code' => curl_errno($ch),
+ 'error' => array(
+ 'message' => curl_error($ch),
+ 'type' => 'CurlException',
+ ),
+ ));
+ curl_close($ch);
+ throw $e;
+ }
+ curl_close($ch);
+ return $result;
+ }
+
+ /**
+ * The name of the Cookie that contains the session.
+ *
+ * @return String the cookie name
+ */
+ protected function getSessionCookieName() {
+ return 'fbs_' . $this->getAppId();
+ }
+
+ /**
+ * Set a JS Cookie based on the _passed in_ session. It does not use the
+ * currently stored session -- you need to explicitly pass it in.
+ *
+ * @param Array $session the session to use for setting the cookie
+ */
+ protected function setCookieFromSession($session=null) {
+ if (!$this->useCookieSupport()) {
+ return;
+ }
+
+ $cookieName = $this->getSessionCookieName();
+ $value = 'deleted';
+ $expires = time() - 3600;
+ $domain = $this->getBaseDomain();
+ if ($session) {
+ $value = '"' . http_build_query($session, null, '&') . '"';
+ if (isset($session['base_domain'])) {
+ $domain = $session['base_domain'];
+ }
+ $expires = $session['expires'];
+ }
+
+ // prepend dot if a domain is found
+ if ($domain) {
+ $domain = '.' . $domain;
+ }
+
+ // if an existing cookie is not set, we dont need to delete it
+ if ($value == 'deleted' && empty($_COOKIE[$cookieName])) {
+ return;
+ }
+
+ if (headers_sent()) {
+ self::errorLog('Could not set cookie. Headers already sent.');
+
+ // ignore for code coverage as we will never be able to setcookie in a CLI
+ // environment
+ // @codeCoverageIgnoreStart
+ } else {
+ setcookie($cookieName, $value, $expires, '/', $domain);
+ }
+ // @codeCoverageIgnoreEnd
+ }
+
+ /**
+ * Validates a session_version=3 style session object.
+ *
+ * @param Array $session the session object
+ * @return Array the session object if it validates, null otherwise
+ */
+ protected function validateSessionObject($session) {
+ // make sure some essential fields exist
+ if (is_array($session) &&
+ isset($session['uid']) &&
+ isset($session['access_token']) &&
+ isset($session['sig'])) {
+ // validate the signature
+ $session_without_sig = $session;
+ unset($session_without_sig['sig']);
+ $expected_sig = self::generateSignature(
+ $session_without_sig,
+ $this->getApiSecret()
+ );
+ if ($session['sig'] != $expected_sig) {
+ self::errorLog('Got invalid session signature in cookie.');
+ $session = null;
+ }
+ // check expiry time
+ } else {
+ $session = null;
+ }
+ return $session;
+ }
+
+ /**
+ * Returns something that looks like our JS session object from the
+ * signed token's data
+ *
+ * TODO: Nuke this once the login flow uses OAuth2
+ *
+ * @param Array the output of getSignedRequest
+ * @return Array Something that will work as a session
+ */
+ protected function createSessionFromSignedRequest($data) {
+ if (!isset($data['oauth_token'])) {
+ return null;
+ }
+
+ $session = array(
+ 'uid' => $data['user_id'],
+ 'access_token' => $data['oauth_token'],
+ 'expires' => $data['expires'],
+ );
+
+ // put a real sig, so that validateSignature works
+ $session['sig'] = self::generateSignature(
+ $session,
+ $this->getApiSecret()
+ );
+
+ return $session;
+ }
+
+ /**
+ * Parses a signed_request and validates the signature.
+ * Then saves it in $this->signed_data
+ *
+ * @param String A signed token
+ * @param Boolean Should we remove the parts of the payload that
+ * are used by the algorithm?
+ * @return Array the payload inside it or null if the sig is wrong
+ */
+ protected function parseSignedRequest($signed_request) {
+ list($encoded_sig, $payload) = explode('.', $signed_request, 2);
+
+ // decode the data
+ $sig = self::base64UrlDecode($encoded_sig);
+ $data = json_decode(self::base64UrlDecode($payload), true);
+
+ if (strtoupper($data['algorithm']) !== 'HMAC-SHA256') {
+ self::errorLog('Unknown algorithm. Expected HMAC-SHA256');
+ return null;
+ }
+
+ // check sig
+ $expected_sig = hash_hmac('sha256', $payload,
+ $this->getApiSecret(), $raw = true);
+ if ($sig !== $expected_sig) {
+ self::errorLog('Bad Signed JSON signature!');
+ return null;
+ }
+
+ return $data;
+ }
+
+ /**
+ * Build the URL for api given parameters.
+ *
+ * @param $method String the method name.
+ * @return String the URL for the given parameters
+ */
+ protected function getApiUrl($method) {
+ static $READ_ONLY_CALLS =
+ array('admin.getallocation' => 1,
+ 'admin.getappproperties' => 1,
+ 'admin.getbannedusers' => 1,
+ 'admin.getlivestreamvialink' => 1,
+ 'admin.getmetrics' => 1,
+ 'admin.getrestrictioninfo' => 1,
+ 'application.getpublicinfo' => 1,
+ 'auth.getapppublickey' => 1,
+ 'auth.getsession' => 1,
+ 'auth.getsignedpublicsessiondata' => 1,
+ 'comments.get' => 1,
+ 'connect.getunconnectedfriendscount' => 1,
+ 'dashboard.getactivity' => 1,
+ 'dashboard.getcount' => 1,
+ 'dashboard.getglobalnews' => 1,
+ 'dashboard.getnews' => 1,
+ 'dashboard.multigetcount' => 1,
+ 'dashboard.multigetnews' => 1,
+ 'data.getcookies' => 1,
+ 'events.get' => 1,
+ 'events.getmembers' => 1,
+ 'fbml.getcustomtags' => 1,
+ 'feed.getappfriendstories' => 1,
+ 'feed.getregisteredtemplatebundlebyid' => 1,
+ 'feed.getregisteredtemplatebundles' => 1,
+ 'fql.multiquery' => 1,
+ 'fql.query' => 1,
+ 'friends.arefriends' => 1,
+ 'friends.get' => 1,
+ 'friends.getappusers' => 1,
+ 'friends.getlists' => 1,
+ 'friends.getmutualfriends' => 1,
+ 'gifts.get' => 1,
+ 'groups.get' => 1,
+ 'groups.getmembers' => 1,
+ 'intl.gettranslations' => 1,
+ 'links.get' => 1,
+ 'notes.get' => 1,
+ 'notifications.get' => 1,
+ 'pages.getinfo' => 1,
+ 'pages.isadmin' => 1,
+ 'pages.isappadded' => 1,
+ 'pages.isfan' => 1,
+ 'permissions.checkavailableapiaccess' => 1,
+ 'permissions.checkgrantedapiaccess' => 1,
+ 'photos.get' => 1,
+ 'photos.getalbums' => 1,
+ 'photos.gettags' => 1,
+ 'profile.getinfo' => 1,
+ 'profile.getinfooptions' => 1,
+ 'stream.get' => 1,
+ 'stream.getcomments' => 1,
+ 'stream.getfilters' => 1,
+ 'users.getinfo' => 1,
+ 'users.getloggedinuser' => 1,
+ 'users.getstandardinfo' => 1,
+ 'users.hasapppermission' => 1,
+ 'users.isappuser' => 1,
+ 'users.isverified' => 1,
+ 'video.getuploadlimits' => 1);
+ $name = 'api';
+ if (isset($READ_ONLY_CALLS[strtolower($method)])) {
+ $name = 'api_read';
+ }
+ return self::getUrl($name, 'restserver.php');
+ }
+
+ /**
+ * Build the URL for given domain alias, path and parameters.
+ *
+ * @param $name String the name of the domain
+ * @param $path String optional path (without a leading slash)
+ * @param $params Array optional query parameters
+ * @return String the URL for the given parameters
+ */
+ protected function getUrl($name, $path='', $params=array()) {
+ $url = self::$DOMAIN_MAP[$name];
+ if ($path) {
+ if ($path[0] === '/') {
+ $path = substr($path, 1);
+ }
+ $url .= $path;
+ }
+ if ($params) {
+ $url .= '?' . http_build_query($params, null, '&');
+ }
+ return $url;
+ }
+
+ /**
+ * Returns the Current URL, stripping it of known FB parameters that should
+ * not persist.
+ *
+ * @return String the current URL
+ */
+ protected function getCurrentUrl() {
+ $protocol = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on'
+ ? 'https://'
+ : 'http://';
+ $currentUrl = $protocol . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
+ $parts = parse_url($currentUrl);
+
+ // drop known fb params
+ $query = '';
+ if (!empty($parts['query'])) {
+ $params = array();
+ parse_str($parts['query'], $params);
+ foreach(self::$DROP_QUERY_PARAMS as $key) {
+ unset($params[$key]);
+ }
+ if (!empty($params)) {
+ $query = '?' . http_build_query($params, null, '&');
+ }
+ }
+
+ // use port if non default
+ $port =
+ isset($parts['port']) &&
+ (($protocol === 'http://' && $parts['port'] !== 80) ||
+ ($protocol === 'https://' && $parts['port'] !== 443))
+ ? ':' . $parts['port'] : '';
+
+ // rebuild
+ return $protocol . $parts['host'] . $port . $parts['path'] . $query;
+ }
+
+ /**
+ * Generate a signature for the given params and secret.
+ *
+ * @param Array $params the parameters to sign
+ * @param String $secret the secret to sign with
+ * @return String the generated signature
+ */
+ protected static function generateSignature($params, $secret) {
+ // work with sorted data
+ ksort($params);
+
+ // generate the base string
+ $base_string = '';
+ foreach($params as $key => $value) {
+ $base_string .= $key . '=' . $value;
+ }
+ $base_string .= $secret;
+
+ return md5($base_string);
+ }
+
+ /**
+ * Prints to the error log if you aren't in command line mode.
+ *
+ * @param String log message
+ */
+ protected static function errorLog($msg) {
+ // disable error log if we are running in a CLI environment
+ // @codeCoverageIgnoreStart
+ if (php_sapi_name() != 'cli') {
+ error_log($msg);
+ }
+ // uncomment this if you want to see the errors on the page
+ // print 'error_log: '.$msg."\n";
+ // @codeCoverageIgnoreEnd
+ }
+
+ /**
+ * Base64 encoding that doesn't need to be urlencode()ed.
+ * Exactly the same as base64_encode except it uses
+ * - instead of +
+ * _ instead of /
+ *
+ * @param String base64UrlEncodeded string
+ */
+ protected static function base64UrlDecode($input) {
+ return base64_decode(strtr($input, '-_', '+/'));
+ }
+}