facebook getLogoutUrl - facebook

facebook, as usual does not work as expected.
on calling
$facebook->getLogoutUrl($params);
using
$params = array( 'next' => 'http://mywebsiteurl.com/loggedout.php' );
The browser view is redirected to loggedout.php, which is good.
Except when the user proceeds to facebook.com they find they are still logged in, which is not good.
So, where do we go from here?
What am i doing wrong?
What did facebook do wrong?

it's because of the cookie. I did the following to fix this issue ...
in the params for the getLogoutUrl method you set your own logout URL:
$facebook->getLogoutUrl(array( 'next' => 'http://www.yourdomain.com/logOut/' ));
and in your logout file you reset the cookie:
setcookie('PHPSESSID', '', time()-3600, '/');
header('Location: http://www.yourdomain.com');

I have the same issue. After returning from the logout URL, calling $facebook->getUser() still returns the user's id.
I got around this by adding a query string to the 'next' parameter, which if set, I treat the user as if they were logged out.

I've had similar issues with the SDK, where using the getLogoutUrl(); with a next parameter does not ever get redirected back to the web-application.
So, I've given up on getting the users to be able to use that functionality to dis-connect my application. Now I just delete their access tokens from our system and tell them to manually de-authorise the application on the FB site - and provide a hyperlink to http://www.facebook.com/settings?tab=applications

Related

How to authenticate when is not required using Perl?

when trying to get access to a page that requires authentication with this code:
my $browser = LWP::UserAgent−>new;
my $url = 'http://www.unicode.org/mail−arch/unicode−ml/y2002−m08/0067.html';
my $response = $browser−>get($url);
an expected error is generated:
Error: Basic realm="Unicode−MailList−Archives"
401 Authorization Required
at http://www.unicode.org/mail−arch/unicode−ml/y2002−m08/0067.html
and this is taken care with:
$browser−>credentials(
'www.unicode.org:80',
'Unicode−MailList−Archives',
'unicode−ml' => 'unicode'
);
But my problem is how to use authentication when it is optional but not required. For example if I want to enter to http://www.coolstuffinc.com/user_main.php, if im logged in it takes me to my user page and if I am not it takes me to the home page.
How can I do so it uses my credentials to enter to the user page.
As always, do like you do if you were browsing: Navigate to the login form, fill it out, submit it, then visit the page you really want to visit.
Logging in will provide you with a cookie that will automatically be submitted in later requests. This is how the site knows who is logged in.

Facebook PHP SDK usage stand alone - how do the Facebook sessions/cookies work?

I'm utilizing the Facebook PHP SDK on its own. I do not want to use the JS SDK at all.
Because getUser(); from the SDK can return a user id even if the user is not logged in, I have opted for using a try/catch statement to check if the user is logged in.
try
{
$me = $CI->facebook->api('/me');
$CI->our_fb['is_fb']='YES';
echo "hello";
}
catch(FacebookApiException $e)
{
echo "catch";
}
This statement is included in the global include file of all of my files (for simplicity).
So, depending on the situation, I generate a Facebook login URL. The expected functionality is that the user logins to Facebook, authorises the app, is returned to the redirect URI set in the login URL at which point the try statement will execute, and $CI->our_fb['is_fb'] will be set.
This is however not happening.
If the user is already logged into Facebook and the app is authorised, it works perfectly. SUCCESS
If the user is not logged into Facebook, once redirected the variable is not set. FAILURE
If the user is logged in but the app is NOT authorised after redirect the variable is not set. FAILURE.
In the latter two cases if you simply refresh the page, the variable is set - SUCCESS. Refreshing the page is however unnecessary/pointless extra effort.
My problem is that if you need to login to FB/or authorise the app e.g the first time you login with FB, you have an additional unneeded refresh, and I don't know why.
I suspect it is something to do with the cookie/session? Which saves the access token that I assume is returned/passed to the SDK automatically not being set at the same time?
Anyone got any ideas?
If you're having an app on facebook (tab or canvas). PHP SDK only get the User ID on initial loading of a page because a signed_request is sent with the request to your app.
But, when the app refreshes, the signed_request is lost (as it's facebook who send it).
So, in this case, you can append the signed_request to every URLs your use in your app - but that's really not optimal as the signed_request won't be regenarated - neither refreshed.
Your only real option is to rely on the JS SDK to set cookie correctly and allow getUser to work as expected. This is required because you're considered as a third-party app in Facebook (being in an iframe) and most browser will block you from setting cookies - so you need a work around handled by the JS SDK for you. You can search for cross-domain cookies or third-party cookie for explanation about the workarounds, but these workaround only work via JS scripting and iframe management.
Also, be sure to setup the JS SDK correctly: channel file, cookie allowed, and send P3P headers (for IE).
You can also check this related question: A proper approach to FB auth
About website, the same mostly stays (but you have no signed_request). At this point, seriously consider using the JS SDK as it's way easier. Or else, you can make sure your app flow follow these guidelines: https://developers.facebook.com/docs/concepts/login/login-architecture/
The way I am seeing this is, you are trying to avoid that refresh if the user is not logged in and precedes to log in after the page has initially loaded.
So what you can do is make an ajax request to another page on your site, say for example id.php, which just loads the php sdk and echo $userid; and then you can grab the user id after login without the refresh.
Basically the cookie is used to save the signed request and session is used to save 'state', 'code', 'access_token', 'user_id'. If the above are present PHP SDK uses them, no matter if they are valid or not.
I think your problem lies in the CODE sent by facebook. Specifically these lines in base_facebook.php:
if ($code && $code != $this->getPersistentData('code')) {
$access_token = $this->getAccessTokenFromCode($code);
...
protected function getAccessTokenFromCode($code, $redirect_uri = null) {
if (empty($code)) {
return false;
}
if ($redirect_uri === null) {
$redirect_uri = $this->getCurrentUrl();
}
...
Because CODE is issued for specific url sometimes there is such situation: Visitor arrives on www.example.com. He givies permissions and is redirected to example.com/login. But the code is not valid there, so the getUserAccessToken returns false. When you refresh the page you get same urls and everything's fine.
You're on the right track of not using getUser() because as I wrote above it's taken from the session if available.

Redirect to facebook app after login from auth dialog

I got some problem with my testing app
$params = array(
'scope' => 'read_stream, publish_stream'
);
$loginUrl = $facebook->getLoginUrl($params);
echo "<script type='text/javascript'>top.location.href = '$loginUrl';</script>";
This is the code I use to send user who has not logged in yet to login
via facebook auth dialog.
The problem is after login using facebook auth dialog
user will be redirected to my site which is not in facebook app.
How can I send user back to facebook app after login using auth dialog ?
Please help
You can use the redirect_uri parameter of getLoginUrl() to tell facebook where you want to send the user after authorization ends (let it be success or failure).
There's a number of restrictions on what you can use there, basically you got three options:
URL under your application's domain.
The canvas path of the application (if it has one): https://apps.facebook.com/YOUR_APP_NAMESPACE
Any page url that has your application installed: https://www.facebook.com/PAGE_USERNAME/app_YOUR_APP_ID
By default, the php sdk takes the current url as redirect_uri. The documentation about these are under the oauth dialog's documentation of the same parameter.
Was google-ing about the same issue and found a solution,so thought might as well answer her.
simply add the following code in the main page.
$config['appBaseUrl'] = "http://apps.facebook.com/your_app_name/";
if(isset($_GET['code']))
{
header("location:" . $config['appBaseUrl']);
exit;
}
$config is the array that i pass while creating the facebook object. In this context,its not necessary to create an array though.

Facebook PHP SDK - Have to reauthenticate during new browser session?

Hopefully this should be quick and easy.
session_start();
include("facebook.php");
$facebook = new Facebook(array(
'appId'=>'xxxxx50274xxxxx',
'secret'=>'xxxxxb932d62fbc6287feb18e5exxxxx',
'cookie'=>true
));
$fbuser = $facebook->getUser();
if (empty($fbuser)){
$fbloginurl=$facebook->getLoginURL();
echo "<html><body><a href='$fbloginurl'>Click</a></body></html>
} else {
die("Authenticated");
}
In this example, the first time I click the link to give permissions to the app to access my FB account, everything works fine. I can keep refreshing the page, and I get the "Authenticated" confirmation.
However, every time I restart the browser (starting a new session), it doesn't authenticate the app automatically and I have to click the link again. Of course as soon as I click the link I am immediately redirected back to the source page and presented with the "Authenticated" confirmation.
Is there any way of not having to click the authentication link during new browser sessions and have it authenticate automatically? I need to do this without a PHP Header directive, as I want the first time the user gives permissions to the app to be triggered by a manual click.
My FB login is persistent ("stay logged in" option is checked).
Thanks a lot for any help.
If I am understanding your scenario correctly (this is not an iframe app, correct?), this is all down to losing the website session cookie when the browser is closed. Once that cookie is gone, there is nothing to identify the user to your server-side code and so no way to know if the user has previously authorized your app.
You need to find a way to persistently identify the user, or at least identify that he has already given permissions. The simplest way would probably be to set your own (permanent) cookie once the user has first authenticated. Then whenever the session cookie is lost, check the presence of the permanent cookie and if it's there, do a PHP redirect to Facebook (which will be invisible to the user). If there is no cookie, present the HTML link to the user like you are doing now.
Comparing it to my code, the only difference I see is that I check to see if $fbuser is valid - if it isn't send me to the login screen. I'm also using top.location.href.
// Login or logout url will be needed depending on current user state.
if ($fbuser) {
$logoutUrl = $facebook->getLogoutUrl();
}
else {
$loginUrl = $facebook->getLoginUrl(array('scope' => 'publish_actions', 'canvas' => 1, 'fbconnect' => 0, 'redirect_uri'=>config_item('facebook_url').$pf));
echo "<html><body><script> top.location.href='" . $loginUrl . "'</script></body></html>";
exit(0);
}
Hope that helps.

Facebook getUser() function returning user ID after logout

I'm developing using the Facebook PHP SDK.
I wanted to make it so that when the user logs out of Facebook, they will automatically be logged out of my website too.
I am using the following code to detect the session, using the session cookie:
$facebook->getUser();
For some reason, the getUser() function still returns the user's Facebook ID, even after they have logged out of Facebook on their website.
Am I to detect the session first using another Function?
On the official documentation example here, is the following excerpt from their comments:
// Get User ID
$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.
This lead me to believe that the session cookie for Facebook would become unset upon Facebook logout?
Kind Regards,
Luke
I have the same issue!
The FB PHP SDK saves those things into the $_SESSION!
You can delete them like this when your user clicks logout:
$_SESSION['fb_'.APP_ID.'_user_id'] = '';
$_SESSION['fb_'.APP_ID.'_access_token'] = '';
Although this is not the final solution, it works for now.
I appreciate comments and solutions on that!
I want to give an alternative, in a way you don't have to handle session stuff. Although, I must warn you this is slower than cleaning up the session, because it relies on a new request. What we're doing in the code below is to check on Facebook if the token is still valid. Here it's:
try {
$facebook->api('/me','GET');
$logged = true;
} catch(FacebookApiException $e) {
$logged = false;
}
In my case, I was doing everything using the JavaScript SDK, so I couldn't clean session on logout. But in my landing page, I was needing a work around to check it before send the response back.
If you're facing something like this, definitely a good solution.
The problem seems to be in php-sdk in basefacebook.php at line 567
protected function getSignedRequestCookieName() {
return 'fbsr'.$this->getAppId();}
This method returns the name of the cookie the sdk is looking for. However, javascript-sdk uses 'fbs_' prefix. Change this to 'fbs_' and it works fine.
return 'fbs'.$this->getAppId();}
$facebook->destroySession();
To destroy the session you can also use:
$facebook->destroySession();