buzzoole code

Facebook : créer une redirection de l’application bienvenue vers le mur

Créer une redirection entre le page de bienvenue et le mur d'une Fan-page Facebook

Créer une redirection entre le page de bienvenue et le mur d'une Fan-page Facebook

Cet article fait suite à celui plubié sur Kriisiis, concernant la création d’un onglet personnalisé pour votre Fan-Page Facebook. J’y explique une technique pour créer une redirection de l’application Bienvenue vers votre mur.

Dans les commentaires sur l’article de Kriisiis, j’apportais mon point de vue sur la procédure citée, en précisant que je connaissais un moyen pour rediriger les Internautes, une fois FAN de votre Page Facebook, vers une autre application. Suite aux réponses des autres Internautes, j’ai donc décidé de rédiger un article rapide présentant cette méthode.

Ce code, trouvé sur un site anglophone, a été revu avec un ami pour le simplifier. Vous pourrez donc le retrouver
ailleurs, plus complexe, en faisant quelques recherches sur le sujet.

Dans votre application bienvenue.php (ou tout autre application), copiez/collez le code ci-dessous en insérant vos données personnelles aux endroits indiqués.

Ensuite, il suffit de transférer votre page, via FTP, sur votre serveur sécurisé, puis de l’intégrer dans votre application Facebook comme il se doit.

Testez la rediretion avec des “j’aime/j’aime plus”, via un autre compte FB pour visualiser le passage des 2
applications : page de bienvenue / mur (ou autre applicatio)n.

Code source d’une page pouvant rediriger vos fans vers le Mur une fois Fan de votre page Facebook.

<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”>
<html>
<head>
<title></title>
<meta http-equiv=”Content-Type” content=”text/html; charset=UTF-8″>

<?php

require_once ‘./facebook.php’;
$app_id = “FACEBOOK_APP_ID”;
$app_secret = “FACEBOOK_SECRET_KEY”;
$facebook = new Facebook(array(
‘appId’ => $app_id,
‘secret’ => $app_secret,
‘cookie’ => true
));
$user = $facebook->getUser();

// We may or may not have this data based on whether the user is logged in.
//
// If we have a $user id here, it means we know the user is logged into
// Facebook, but we don’t know if the access token is valid. An access
// token is invalid if the user logged out of Facebook.

if ($user) {
try {
// Proceed knowing you have a logged in user who’s authenticated.
$user_profile = $facebook->api(‘/me’);
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
}

$signed_request = $facebook->getSignedRequest();
$like_status = $signed_request[“page”][“liked”];

if ($like_status) { ?>
<script type=”text/javascript”>
if (top != self) top.window.location = ‘URL DE LA PAGE FB DE DESTINATION avec HTTPS://… (exemple : le MUR)’;
</script>
<?php
}

?>
</head>

<body style=”padding:0;margin:0;”>

<div id=”fb-root”></div>
<script>
window.fbAsyncInit = function() {
FB.init({
appId : ‘FACEBOOK_APP_ID’, // App ID
channelUrl : ‘//VOTRE NOM DE DOMAINE/channel.html’, // Channel File
status : true, // check login status
cookie : true, // enable cookies to allow the server to access the session
oauth : true, // enable OAuth 2.0
xfbml : true // parse XFBML
});

// Additional initialization code here
};

// Load the SDK Asynchronously
(function(d){
var js, id = ‘facebook-jssdk’; if (d.getElementById(id)) {return;}
js = d.createElement(‘script’); js.id = id; js.async = true;
js.src = “//connect.facebook.net/en_US/all.js”;
d.getElementsByTagName(‘head’)[0].appendChild(js);
}(document));
</script>

CONTENU DE LA PAGE DE BIENVENUE (ou toute autre page)

</body>
</html>

S’en suit ci-dessous les pages à créer, appelléee dans le code source ci-dessus.

Code source de la page channel.html :

<script src=”//connect.facebook.net/en_US/all.js”></script>

Code source de la page facebook.php :

<?php
/**
* Copyright 2011 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the “License”); you may
* not use this file except in compliance with the License. You may obtain
* a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an “AS IS” BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/

require_once “base_facebook.php”;

/**
* Extends the BaseFacebook class with the intent of using
* PHP sessions to store user ids and access tokens.
*/
class Facebook extends BaseFacebook
{
/**
* Identical to the parent constructor, except that
* we start a PHP session to store the user ID and
* access token if during the course of execution
* we discover them.
*
* @param Array $config the application configuration.
* @see BaseFacebook::__construct in facebook.php
*/
public function __construct($config) {
if (!session_id()) {
session_start();
}
parent::__construct($config);
}

protected static $kSupportedKeys =
array(‘state’, ‘code’, ‘access_token’, ‘user_id’);

/**
* Provides the implementations of the inherited abstract
* methods. The implementation uses PHP sessions to maintain
* a store for authorization codes, user ids, CSRF states, and
* access tokens.
*/
protected function setPersistentData($key, $value) {
if (!in_array($key, self::$kSupportedKeys)) {
self::errorLog(‘Unsupported key passed to setPersistentData.’);
return;
}

$session_var_name = $this->constructSessionVariableName($key);
$_SESSION[$session_var_name] = $value;
}

protected function getPersistentData($key, $default = false) {
if (!in_array($key, self::$kSupportedKeys)) {
self::errorLog(‘Unsupported key passed to getPersistentData.’);
return $default;
}

$session_var_name = $this->constructSessionVariableName($key);
return isset($_SESSION[$session_var_name]) ?
$_SESSION[$session_var_name] : $default;
}

protected function clearPersistentData($key) {
if (!in_array($key, self::$kSupportedKeys)) {
self::errorLog(‘Unsupported key passed to clearPersistentData.’);
return;
}

$session_var_name = $this->constructSessionVariableName($key);
unset($_SESSION[$session_var_name]);
}

protected function clearAllPersistentData() {
foreach (self::$kSupportedKeys as $key) {
$this->clearPersistentData($key);
}
}

protected function constructSessionVariableName($key) {
return implode(‘_’, array(‘fb’,
$this->getAppId(),
$key));
}
}

Code source de la page Base_facebook.php :

<?php
/**
* Copyright 2011 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the “License”); you may
* not use this file except in compliance with the License. You may obtain
* a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an “AS IS” BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/

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.
*
* @return 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.
*
* @return 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. This class provides
* a majority of the functionality needed, but the class is abstract
* because it is designed to be sub-classed. The subclass must
* implement the three abstract methods listed at the bottom of
* the file.
*
* @author Naitik Shah <naitik@facebook.com>
*/
abstract class BaseFacebook
{
/**
* Version.
*/
const VERSION = ‘3.0.1’;

/**
* Default options for curl.
*/
public static $CURL_OPTS = array(
CURLOPT_CONNECTTIMEOUT => 10,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_TIMEOUT => 60,
CURLOPT_USERAGENT => ‘facebook-php-3.0’,
);

/**
* List of query parameters that get automatically dropped when rebuilding
* the current URL.
*/
protected static $DROP_QUERY_PARAMS = array(
‘code’,
‘state’,
‘signed_request’,
);

/**
* Maps aliases to Facebook domains.
*/
public static $DOMAIN_MAP = array(
‘api’ => ‘https://api.facebook.com/’,
‘api_video’ => ‘https://api-video.facebook.com/’,
‘api_read’ => ‘https://api-read.facebook.com/’,
‘graph’ => ‘https://graph.facebook.com/’,
‘www’ => ‘https://www.facebook.com/’,
);

/**
* The Application ID.
*
* @var string
*/
protected $appId;

/**
* The Application API Secret.
*
* @var string
*/
protected $apiSecret;

/**
* The ID of the Facebook user, or 0 if the user is logged out.
*
* @var integer
*/
protected $user;

/**
* The data from the signed_request token.
*/
protected $signedRequest;

/**
* A CSRF state variable to assist in the defense against CSRF attacks.
*/
protected $state;

/**
* The OAuth access token received in exchange for a valid authorization
* code. null means the access token has yet to be determined.
*
* @var string
*/
protected $accessToken = null;

/**
* Indicates if the CURL based @ syntax for file uploads is enabled.
*
* @var boolean
*/
protected $fileUploadSupport = false;

/**
* Initialize a Facebook Application.
*
* The configuration:
* – appId: the application ID
* – secret: the application secret
* – 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[‘fileUpload’])) {
$this->setFileUploadSupport($config[‘fileUpload’]);
}

$state = $this->getPersistentData(‘state’);
if (!empty($state)) {
$this->state = $this->getPersistentData(‘state’);
}
}

/**
* Set the Application ID.
*
* @param string $appId The Application ID
* @return BaseFacebook
*/
public function setAppId($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 $apiSecret The API Secret
* @return BaseFacebook
*/
public function setApiSecret($apiSecret) {
$this->apiSecret = $apiSecret;
return $this;
}

/**
* Get the API Secret.
*
* @return string the API Secret
*/
public function getApiSecret() {
return $this->apiSecret;
}

/**
* Set the file upload support status.
*
* @param boolean $fileUploadSupport The file upload support status.
* @return BaseFacebook
*/
public function setFileUploadSupport($fileUploadSupport) {
$this->fileUploadSupport = $fileUploadSupport;
return $this;
}

/**
* Get the file upload support status.
*
* @return boolean true if and only if the server supports file upload.
*/
public function useFileUploadSupport() {
return $this->fileUploadSupport;
}

/**
* Sets the access token for api calls. Use this if you get
* your access token by other means and just want the SDK
* to use it.
*
* @param string $access_token an access token.
* @return BaseFacebook
*/
public function setAccessToken($access_token) {
$this->accessToken = $access_token;
return $this;
}

/**
* Determines the access token that should be used for API calls.
* The first time this is called, $this->accessToken is set equal
* to either a valid user access token, or it’s set to the application
* access token if a valid user access token wasn’t available. Subsequent
* calls return whatever the first call returned.
*
* @return string The access token
*/
public function getAccessToken() {
if ($this->accessToken !== null) {
// we’ve done this already and cached it. Just return.
return $this->accessToken;
}

// first establish access token to be the application
// access token, in case we navigate to the /oauth/access_token
// endpoint, where SOME access token is required.
$this->setAccessToken($this->getApplicationAccessToken());
if ($user_access_token = $this->getUserAccessToken()) {
$this->setAccessToken($user_access_token);
}

return $this->accessToken;
}

/**
* Determines and returns the user access token, first using
* the signed request if present, and then falling back on
* the authorization code if present. The intent is to
* return a valid user access token, or false if one is determined
* to not be available.
*
* @return string A valid user access token, or false if one
* could not be determined.
*/
protected function getUserAccessToken() {
// first, consider a signed request if it’s supplied.
// if there is a signed request, then it alone determines
// the access token.
$signed_request = $this->getSignedRequest();
if ($signed_request) {
if (array_key_exists(‘oauth_token’, $signed_request)) {
$access_token = $signed_request[‘oauth_token’];
$this->setPersistentData(‘access_token’, $access_token);
return $access_token;
}

// signed request states there’s no access token, so anything
// stored should be cleared.
$this->clearAllPersistentData();
return false; // respect the signed request’s data, even
// if there’s an authorization code or something else
}

$code = $this->getCode();
if ($code && $code != $this->getPersistentData(‘code’)) {
$access_token = $this->getAccessTokenFromCode($code);
if ($access_token) {
$this->setPersistentData(‘code’, $code);
$this->setPersistentData(‘access_token’, $access_token);
return $access_token;
}

// code was bogus, so everything based on it should be invalidated.
$this->clearAllPersistentData();
return false;
}

// as a fallback, just return whatever is in the persistent
// store, knowing nothing explicit (signed request, authorization
// code, etc.) was present to shadow it (or we saw a code in $_REQUEST,
// but it’s the same as what’s in the persistent store)
return $this->getPersistentData(‘access_token’);
}

/**
* 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;
}

/**
* Get the UID of the connected user, or 0
* if the Facebook user is not connected.
*
* @return string the UID if available.
*/
public function getUser() {
if ($this->user !== null) {
// we’ve already determined this and cached the value.
return $this->user;
}

return $this->user = $this->getUserFromAvailableData();
}

/**
* Determines the connected user by first examining any signed
* requests, then considering an authorization code, and then
* falling back to any persistent store storing the user.
*
* @return integer The id of the connected Facebook user,
* or 0 if no such user exists.
*/
protected function getUserFromAvailableData() {
// if a signed request is supplied, then it solely determines
// who the user is.
$signed_request = $this->getSignedRequest();
if ($signed_request) {
if (array_key_exists(‘user_id’, $signed_request)) {
$user = $signed_request[‘user_id’];
$this->setPersistentData(‘user_id’, $signed_request[‘user_id’]);
return $user;
}

// if the signed request didn’t present a user id, then invalidate
// all entries in any persistent store.
$this->clearAllPersistentData();
return 0;
}

$user = $this->getPersistentData(‘user_id’, $default = 0);
$persisted_access_token = $this->getPersistentData(‘access_token’);

// use access_token to fetch user id if we have a user access_token, or if
// the cached access token has changed.
$access_token = $this->getAccessToken();
if ($access_token &&
$access_token != $this->getApplicationAccessToken() &&
!($user && $persisted_access_token == $access_token)) {
$user = $this->getUserFromAccessToken();
if ($user) {
$this->setPersistentData(‘user_id’, $user);
} else {
$this->clearAllPersistentData();
}
}

return $user;
}

/**
* 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:
* – redirect_uri: the url to go to after a successful login
* – scope: comma separated list of requested extended perms
*
* @param array $params Provide custom parameters
* @return string The URL for the login flow
*/
public function getLoginUrl($params=array()) {
$this->establishCSRFTokenState();
$currentUrl = $this->getCurrentUrl();
return $this->getUrl(
‘www’,
‘dialog/oauth’,
array_merge(array(
‘client_id’ => $this->getAppId(),
‘redirect_uri’ => $currentUrl, // possibly overwritten
‘state’ => $this->state),
$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.
*
* @return mixed 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);
}
}

/**
* Get the authorization code from the query parameters, if it exists,
* and otherwise return false to signal no authorization code was
* discoverable.
*
* @return mixed The authorization code, or false if the authorization
* code could not be determined.
*/
protected function getCode() {
if (isset($_REQUEST[‘code’])) {
if ($this->state !== null &&
isset($_REQUEST[‘state’]) &&
$this->state === $_REQUEST[‘state’]) {

// CSRF state has done its job, so clear it
$this->state = null;
$this->clearPersistentData(‘state’);
return $_REQUEST[‘code’];
} else {
self::errorLog(‘CSRF state token does not match one provided.’);
return false;
}
}

return false;
}

/**
* Retrieves the UID with the understanding that
* $this->accessToken has already been set and is
* seemingly legitimate. It relies on Facebook’s Graph API
* to retrieve user information and then extract
* the user ID.
*
* @return integer Returns the UID of the Facebook user, or 0
* if the Facebook user could not be determined.
*/
protected function getUserFromAccessToken() {
try {
$user_info = $this->api(‘/me’);
return $user_info[‘id’];
} catch (FacebookApiException $e) {
return 0;
}
}

/**
* Returns the access token that should be used for logged out
* users when no authorization code is available.
*
* @return string The application access token, useful for gathering
* public information about users and applications.
*/
protected function getApplicationAccessToken() {
return $this->appId.’|’.$this->apiSecret;
}

/**
* Lays down a CSRF state token for this process.
*
* @return void
*/
protected function establishCSRFTokenState() {
if ($this->state === null) {
$this->state = md5(uniqid(mt_rand(), true));
$this->setPersistentData(‘state’, $this->state);
}
}

/**
* Retrieves an access token for the given authorization code
* (previously generated from www.facebook.com on behalf of
* a specific user). The authorization code is sent to graph.facebook.com
* and a legitimate access token is generated provided the access token
* and the user for which it was generated all match, and the user is
* either logged in to Facebook or has granted an offline access permission.
*
* @param string $code An authorization code.
* @return mixed An access token exchanged for the authorization code, or
* false if an access token could not be generated.
*/
protected function getAccessTokenFromCode($code) {
if (empty($code)) {
return false;
}

try {
// need to circumvent json_decode by calling _oauthRequest
// directly, since response isn’t JSON format.
$access_token_response =
$this->_oauthRequest(
$this->getUrl(‘graph’, ‘/oauth/access_token’),
$params = array(‘client_id’ => $this->getAppId(),
‘client_secret’ => $this->getApiSecret(),
‘redirect_uri’ => $this->getCurrentUrl(),
‘code’ => $code));
} catch (FacebookApiException $e) {
// most likely that user very recently revoked authorization.
// In any event, we don’t have an access token, so say so.
return false;
}

if (empty($access_token_response)) {
return false;
}

$response_params = array();
parse_str($access_token_response, $response_params);
if (!isset($response_params[‘access_token’])) {
return false;
}

return $response_params[‘access_token’];
}

/**
* Invoke the old restserver.php endpoint.
*
* @param array $params Method call object
*
* @return mixed The decoded response object
* @throws FacebookApiException
*/
protected function _restserver($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 $params The query/post data
*
* @return mixed The decoded response object
* @throws FacebookApiException
*/
protected function _graph($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’])) {
$this->throwAPIException($result);
}

return $result;
}

/**
* Make a OAuth Request.
*
* @param string $url The path (required)
* @param array $params The query/post data
*
* @return string The decoded response object
* @throws FacebookApiException
*/
protected function _oauthRequest($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 overridden 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 $ch Initialized curl handle
*
* @return string The response text
*/
protected function makeRequest($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 (curl_errno($ch) == 60) { // CURLE_SSL_CACERT
self::errorLog(‘Invalid or no certificate authority found, ‘.
‘using bundled information’);
curl_setopt($ch, CURLOPT_CAINFO,
dirname(__FILE__) . ‘/fb_ca_chain_bundle.crt’);
$result = curl_exec($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;
}

/**
* Parses a signed_request and validates the signature.
*
* @param string $signed_request A signed token
* @return array The payload inside it or null if the sig is wrong
*/
protected function parseSignedRequest($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)])) {
$name = ‘api_read’;
} else if (strtolower($method) == ‘video.upload’) {
$name = ‘api_video’;
}
return self::getUrl($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);

$query = ”;
if (!empty($parts[‘query’])) {
// drop known fb params
$params = explode(‘&’, $parts[‘query’]);
$retained_params = array();
foreach ($params as $param) {
if ($this->shouldRetainParam($param)) {
$retained_params[] = $param;
}
}

if (!empty($retained_params)) {
$query = ‘?’.implode($retained_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;
}

/**
* Returns true if and only if the key or key/value pair should
* be retained as part of the query string. This amounts to
* a brute-force search of the very small list of Facebook-specific
* params that should be stripped out.
*
* @param string $param A key or key/value pair within a URL’s query (e.g.
* ‘foo=a’, ‘foo=’, or ‘foo’.
*
* @return boolean
*/
protected function shouldRetainParam($param) {
foreach (self::$DROP_QUERY_PARAMS as $drop_query_param) {
if (strpos($param, $drop_query_param.’=’) === 0) {
return false;
}
}

return true;
}

/**
* Analyzes the supplied result to see if it was thrown
* because the access token is no longer valid. If that is
* the case, then the persistent store is cleared.
*
* @param $result array A record storing the error message returned
* by a failed API call.
*/
protected function throwAPIException($result) {
$e = new FacebookApiException($result);
switch ($e->getType()) {
// OAuth 2.0 Draft 00 style
case ‘OAuthException’:
// OAuth 2.0 Draft 10 style
case ‘invalid_token’:
$message = $e->getMessage();
if ((strpos($message, ‘Error validating access token’) !== false) ||
(strpos($message, ‘Invalid OAuth access token’) !== false)) {
$this->setAccessToken(null);
$this->user = 0;
$this->clearAllPersistentData();
}
}

throw $e;
}
/**
* Prints to the error log if you aren’t in command line mode.
*
* @param string $msg Log message
*/
protected static function errorLog($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 $input base64UrlEncoded string
* @return string
*/
protected static function base64UrlDecode($input) {
return base64_decode(strtr($input, ‘-_’, ‘+/’));
}

/**
* Each of the following four methods should be overridden in
* a concrete subclass, as they are in the provided Facebook class.
* The Facebook class uses PHP sessions to provide a primitive
* persistent store, but another subclass–one that you implement–
* might use a database, memcache, or an in-memory cache.
*
* @see Facebook
*/

/**
* Stores the given ($key, $value) pair, so that future calls to
* getPersistentData($key) return $value. This call may be in another request.
*
* @param string $key
* @param array $value
*
* @return void
*/
abstract protected function setPersistentData($key, $value);

/**
* Get the data for $key, persisted by BaseFacebook::setPersistentData()
*
* @param string $key The key of the data to retrieve
* @param boolean $default The default value to return if $key is not found
*
* @return mixed
*/
abstract protected function getPersistentData($key, $default = false);

/**
* Clear the data with $key from the persistent storage
*
* @param string $key
* @return void
*/
abstract protected function clearPersistentData($key);

/**
* Clear all data from the persistent storage
*
* @return void
*/
abstract protected function clearAllPersistentData();
}

Rendez-vous sur Hellocoton !

Leave a Reply

8 comments

  1. FilGB

    Waou ! Un “simple” extrait de code ? :)

    N’ayant pas un profil très technique, je vais avoir du mal à me dépatouiller de tout cela. Les landing pages que je fais pour le moment sont de simples pages en HTML. Et une landing page = un fichier html.
    Là je vois qu’il y a au moins 3 pages concernées. Il faut que je prenne le temps de me poser.

    Merci beaucoup pour cet article que je bookmark de ce pas !

  2. xerel

    Salut j’ai testé le code il marche mais une fois que l’on a cliqué sur j’aime, en fait ça nous enmene sur la page dont on à inscris le lien, mais comment faire pour rediriger vers le mur facebook de la page plutot que sur cette page https ? dans le commentaire en plus tu écris “URL DE LA PAGE FB DE DESTINATION avec https://… (exemple : le MUR)”
    Mais quel est l’url d’un mur d’une page fan de fb ? sachant que selon l’utilisateur elle doit changer vue que les identifiants session ne sont pas les même pour tous non ?

    • tu vas sur ton mur et tu copie/colle l’url de celui-ci ;-D
      en fait les scripts prennent en compte l’id de ta page, puis regarde si l’id de l’internaute est “fan” ou pas, s’il n’est pas fan il reste là, s’il est fan il est redirigé vers le mur

  3. Salut Papablogueur !

    Et merci pour cet article ! Par contre, avec le passage à Timeline, cette manipulation fonctionne toujours ?

    En sachant que… L’onglet d’accueil n’est plus qu’une chimère en dehors du trafic payant (avec la Publicité Facebook).

    A plus !

    • oui j’ai appris cela entre temps… enfin au moins cela à servi au moment où j’ai écris l’article

  4. Pingback: Pour tout savoir sur la Timeline des pages Facebook | Papa Blogueur

  5. Un grand merci pour cet article. Même si je ne suis pas souvent sur Facebook, cela peut toujours servir.