Facebook.php code for application developers

July 1, 2010 by: sensehow 2

Tweet

The below is the code for facebook.php file required by application developers.It can used for various purposes.I have added it here so that it may be easy for my readers.The original source is http://github.com/facebook/php-sdk/blob/master/src/facebook.php and you have to copy the below code to notepad and save as facebook.php

<?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;
    $msg  = isset($result['error'])
              ? $result['error']['message'] : $result['error_msg'];
    parent::__construct($msg, $code);
  }
  /**
   * Return the associated result object returned by the API server.
   *
   * @returns Array the result from the API server
   */
  public function getResult() {
    return $this->result;
  }
  /**
   * Returns the associated type for the error. This will default to
   * 'Exception' when a type is not available.
   *
   * @return String
   */
  public function getType() {
    return
      isset($this->result['error']) && isset($this->result['error']['type'])
      ? $this->result['error']['type']
      : '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 = '2.0.5';
  /**
   * 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',
  );
  /**
   * 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;
  /**
   * 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 = '';
  /**
   * 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
   *
   * @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']);
    }
  }
  /**
   * 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 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 $this;
  }
  /**
   * Get the session object. This will automatically look for a signed session
   * sent via the Cookie or Query Parameters if needed.
   *
   * @return Array the session
   */
  public function getSession() {
    if (!$this->sessionLoaded) {
      $session = null;
      $write_cookie = true;
      // try loading session from $_REQUEST
      if (isset($_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;
  }
  /**
   * 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()) {
    $session = $this->getSession();
    return $this->getUrl(
      'www',
      'logout.php',
      array_merge(array(
        'api_key'     => $this->getAppId(),
        'next'        => $this->getCurrentUrl(),
        'session_key' => $session['session_key'],
      ), $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);
      if ($e->getType() === 'OAuthException') {
        $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'])) {
      $session = $this->getSession();
      // either user session signed, or app signed
      if ($session) {
        $params['access_token'] = $session['access_token'];
      } else {
        $params['access_token'] = $this->getAppId() .'|'. $this->getApiSecret();
      }
    }
    // json_encode all params values that are not strings
    foreach ($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;
    $opts[CURLOPT_POSTFIELDS] = http_build_query($params, null, '&');
    $opts[CURLOPT_URL] = $url;
    curl_setopt_array($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::error_log('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($session['session_key']) &&
        isset($session['secret']) &&
        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::error_log('Got invalid session signature in cookie.');
        $session = null;
      }
      // check expiry time
    } else {
      $session = null;
    }
    return $session;
  }
  /**
   * 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);
    }
    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);
      }
    }
    // 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 error_log($msg) {
    // disable error log if we are running in a CLI environment
    // @codeCoverageIgnoreStart
    if (php_sapi_name() != 'cli') {
      error_log($msg);
    }
    // uncomment this if you want to see the errors on the page
    // print 'error_log: '.$msg."n";
    // @codeCoverageIgnoreEnd
  }
}

Related posts:

1. How to find who unfriended you on Facebook using Facebook friend checker application
2. How to display facebook fan count in text in your blog
3. Facebook application for iPad live
4. How to enable facebook chat on pidgin in windows
5. How to integrate facebook with Google+
6. How to import your facebook contacts to Google+