I don’t know if there is a term for this issue already. So will try to explain it.
The question.
How to get to know from FB Login web that a user has already logged in in native FB app and use that auth session to login a user in web app? So that a user doesn’t need to see FB login dialog and provide their credentials again.
The problem.
There are users who never use FB in mobile browsers on smart phones. Only FB native app.
So when a user tries to login with FB in my web app, they are always asked to provide their credentials, email and password. And users complain that they are logged in already and don’t understand why they’re asked to login again. Many just do not remember their passwords.
So, does FB Login API foresee this use case, a combination of logins? Is it possible to implement it?
Similar question Facebook login to web via native FB app
UPD1:
Found this here.
However the question still remains: How to login in web app seamlessly without login dialog if logged in in FB native app?
Once someone has created an account on one platform, they can log into your app — often with a single click — on all your other platforms.
Related
API page is here: https://developers.facebook.com/docs/javascript/reference/v2.6
As far as I know,
If users have already authorized a web app(a website), then invoking FB.login() and FB.logout() in the web app is essentially logging user in or out of Facebook and return the web app with some data(of course you need access token to do this). Assume you have two pages opened, one is your web app, the other is facebook.com. Both logged out initially. Now if you log in with your Facebook account in the web app page, and then if you refresh the other page, you will find that both are logged in. It's similar for the case of logging out.
Well, correct me if my understanding is wrong. I totally understand there are reasons for the logic.
Is there a way to log out users from by web app but keep them logged in with the Facebook and without revoking permission?
I've tried with Google+ OAuth. It seems that using Google+ API is able to log out users from the web app and keep them logged in with Google+.
Well it is how it should be. You want your app to be an interface for the "Facebook app" login, why is that? Consider the scenarios from the user's point of view-
User is logged-in and browsing facebook. He found the useful application of yours and login to your app(providing required permissions). Before leaving your app, he logouts from the app. He then gets back to the Facebook and continue browsing there. All good!
User in NOT logged-in to the facebook. He logs into your app, browse your app then logs out of it. Then, when he open the facebook.com why will he expect that he should be looged-in to facebook automatically? I think he wont think that and he'll login to facebook and continue.
The point is simple here-
if user logs into facebook, he'll be logged-in until and unless he logs out from facebook.
if user is not logged into facebook but logs into your app, he will be logged-in to the facebook until he logs out from your app.
I am implementing Facebook Login (for the web) for the first time and I had some questions regarding the users session and and the best practices for handling logout. Right now, I am using a combination of the JS SDK (only for login flow if js is enabled) and PHP SDK.
Question 1: Should I save the Facebook access token in a PHP session or use the built in "cookies: true" feature in the SDK.
Question 2: If a user that signed up via Facebook returns to the site after a few days, should they be auto logged in, or have to click a login via Facebook button, then just be logged in?
Question 3: If a FB logged in user logs out of my site, should I log them out of Facebook or just my site?
Question 4: If a FB logged in user logs out of Facebook while also on my site (different tab) should I automatically log them out of my site?
1) You can save the access token in a database (but be wary of the expiry date) or save it in a session. Cookies would be the easiest way to manage this and takes care of (2).
2) Depending on how your handle the sessions and the SDK you use, the use would automatically be logged in (e.g. JavaScript method FB.getLoginStatus() to detect if the app has already been authed). You should have a "Login with Facebook" button on your app in any case, for new users.
3) If you use the logout methods in the SDK (e.g. FB.logout() in JavaScript SDK), the user will be logged out of both your site and Facebook. This really depends on how you want to handle this. You can log them out if your site by deleting the session / cookie.
4) You should alway check to see if the user is logged in whenever an action is taken on your site. If the user logs out of Facebook while on your site, eventually, your site should pick it up (using FB.getLoginStatus()) and ask them to login again.
3) Facebook will decide if a user should be logged out of Facebook also or only your site/app, at least when using the JS SDK. From their docs, see link for some case examples:
"The method FB.logout() logs the user out of your site and, in some
cases, Facebook." - Facebook docs
well i have used the facebook api couple of times. But last day i just came across a site which was really new to me. Heres the scenario
If a user is logged in at facebook and comes to my site, he will
automatically be logged in without asking him and also if user logs
out of my site he gets logged out of facebook. But the site i saw
yesterday, they had handled it perfectly, user dose not logs in their
site automatically and even if user logs out from their site, he does
not gets logged out of facebook.
So any help? what is this technique called? or any relevant help?
Best Regards
most site handled the login/authenication by using the login status of the user at facebook ends.
to do what u wants, simply add an additional layer of authentication / login status checking at your own site.
The site level login status is to be retained only for the current session. In other words, once the user went away from the site, the site level login status is gone. With this, when the user returns, you know that he needs to login again.
when the user logged out from your site, you only log him out of your site and do nothing about facebook login
Using the Facebook SDK it will likely tell you the user is logged out when not logged into Facebook, which in theory is the correct behaviour of the whole system, as Facebook want user's to always be connected to Facebook, I quote facebook:
As long as the user is signed into Facebook, they are automatically signed into your site as well.
So if they aren't connected to Facebook, you aren't connected to other sites. In a way it's a deterrant and increases Facebooks market.
But anyhow, it's likely the site you are describing are implementing their own authentican system rather than using Facebook's own SDK, or if they are using the SDK they are using it in moderation and understand about cookies/the above.
The flow to allow the user to be logged into Facebook but out of your site is as so:
When a user logs out of their site, it will unset session data for the site's own application, and also unset Facebook cookies, etc. That way the user is still logged into Facebook but out of your site.
When they try to log in again, Facebook will detect no cookies are available and hence will re-authenticate and pass you onto the url as passed during the authentication process. Your site will then login the user to the site's own application, setting any session variables, etc.
you need to check how you are handling the FB logins and sessions at your end..
my guess is you check the is login at your site and there are some access_tokens which are as per your app id in the cookies of your browser which are helping you to log in ..
and when logging out from your site you are explicitly logging out the user from FB as well
( thats what you are describing atleast )
you seem to be explicitly calling logout or clearing the cookies for fb app id ..
I'm implementing facebook connect for my iPhone app. The current facebook SDK would keep you logged in unless you log out explicitly, which is fine with me as stay logged in is actually the requirement. However, I don't want the users to go press the log in button if they never logged out. In this case, I won't be able to grab the facebook object, which I'll need in other parts of my app. So I was planning to simulate the log in event anyways, but that led me to another problem: even though permissions are granted to my facebook app before, it will still pop up the authorization dialog to my users saying they have granted permissions to my app. My question is, how do I hide this? Or, is there a way that I can grab the valid facebook object without calling authorize on my facebook object when my app is restarted and the user stayed logged in?
Any suggestion would be appreciated.
You could redirect the user to https://www.facebook.com/login.php?api_key=<YOUR_APP_ID>. (This is the URL that the PHP Facebook SDK returns when you call getLoginUrl()).This will avoid the dialog and still allow users to authorize your app.
Here's the problem,
I want to have the user auto login to my MVC3 website if they already login from facebook.com.
If they are not login from facebook.com, I will just simply show a login button and they can login by clicking on it as usual.
I cant seem to find a way to detect whether user had login from facebook.com unless I force the application to direct go into LoginUrl of Facebook, which is not good for user who was not logged in as this will prompt them a page where they have to login. I still want to allow guest access without facebook account.
Any idea? Thanks a million.
EDIT:
Sorry I forgot to mentioned the situation only apply to user who approve to use my app. Once they approve to use my app, I'll be able to detect their facebook login status.
The answer is: You can't. At least not without violating the facebook TOS and probably at least one or two laws.
EDIT: Your original question sounded like you wanted to try and hijack the facebook user session. What you are talking about here in the comments requires you to use facebook connect / facebook for websites.
You would want to start here: https://developers.facebook.com/docs/guides/web