Why are Facebook requests coming in as both POST and GET requests? - facebook

I am writing a Facebook Tab application. I have set it up to be dynamic based on the page that the Facebook user is adding our tab to. When developing, all of my requests are coming to my application as POST requests and included the signed_request parameter. As soon as I got this thing on our production server, it started sending all requests as GET nd did not include the signed_request. The only changes that I made prior to launching was to modify the URLs in the Facebook tab settings to point to our server as opposed to localhost. What is going on here? Why is Facebook changing the request type?

Related

Facebook Login - URL Blocked - Can't add new redirect URI's

I have a website that uses the Facebook Login feature successfully and it still works as we speak. But I want to use the same facebook app on another website using the same keys etc...
But for some reason, even though I have added the correct URI's into the OAuth part of the Facebook page, I still get:
URL blocked: This redirect failed because the redirect URI is not
white-listed in the app's client OAuth settings. Make sure that the
client and web OAuth logins are on and add all your app domains as
valid OAuth redirect URIs.
Does anyone have any ideas on where I can start to find out why Facebook isn't accepting these new urls?
Okay, it seems to be working now - perhaps was a timing issue which was wierd because it updated straight away on previous sites.
Thanks again for the help though WizKid!

Facebook App webhooks: Callback URL & Page tab

Hi I am held up with couple of problems from past couple of days. Please can anyone help me out.
I want to get the real time updates of my facebook page. I created an App & added it as the Page tab but I am getting the below message when i clicked the tab in the facebook page.
Method Not Allowed Error 405
Also when subscribing the real time updates/webhooks in facebook, is it necessary to give domain name/callback.php in callback URL? I mean I just want to test the flow right now and don't want to buy a domain for testing.
Also when i am putting this https://graph.facebook.com//subscriptions?access_token=****
I am just getting
{
"data": [
]
}
Subscribing to a page for updates is not done by installing it as a page tab app any more, but by making a POST request to /page/subscriptions
Method Not Allowed means your server did not accept a POST request to the URL. Facebook makes a POST request to load an app into a page tab. If you tried to use that same URL as your webhook callback URL, you need it to accept POST requests as well.
Of course the URL needs to be reachable from the outside, otherwise Facebook could not make a POST request to it. As far as I know Facebook does not accept IP addresses, you need to use a domain name. Plus, webhooks now require an HTTPS URL, with a valid SSL certificate. Self-signed certificates are not accepted, so you practically have no other choice than to use a "real" domain, dyndns or something won't work.
That's because you have not actually subscribed your app for updates of the page. Again, that has nothing to do any more with page tabs, it needs a POST request to that endpoint.

Facebook Login link redirects straight back to my application without ever showing login dialog

I am attempting to implement a simple Facebook login flow for a web application using HTTP redirects, as detailed at https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow/v2.2.
For the purposes of making this question generic, let's say the application URL is www.example.com/app.php. On the application page, there is a link which directs users to Facebook's OAuth endpoint, where ideally:
they log in to Facebook (if not already logged in) and approve my application permission to access their public profile
they are then redirected back to my application's URL along with some extra parameters appended (e.g. www.example.com/app.php?code=...&access_token=... if the login was successful, or www.example.com/app.php?error_reason=...&error=...&error_description=... if login/app approval was unsuccessful)
The Facebook OAuth endpoint is:
www.facebook.com/dialog/oauth?client_id=12345&redirect_uri=www.xyz.com/app.php
where I have filled in the client_id and redirect_uri parameters with my application's ID and my application's URL respectively.
What actually happens whenever I access the link is that it immediately redirects back to my application's homepage - without ever showing a login dialog of any kind. This happens with Firefox and with Chrome - both when I am logged in to Facebook and when I am not, in normal sessions and in incognito sessions with no plugins enabled. From the browser inspector, I can see that the Facebook OAuth page is definitely requested but is straight away 302 redirecting to my application page with just a code parameter appended.
www.example.com/app.php?code=...
This also happens when the Facebook OAuth link is accessed from pages other than my application's URL (e.g. if I click the link from www.example.com/other_page.htm).
I am unsure what I am doing wrong here; the application URL (www.example.com/app.php) is approved on my app dashboard in as many places as I could find, and changing the request_uri parameter to any other URL results in an error page. I have also tried urlencode()ing my application URL before passing it in the request_uri parameter, but the result remains the same. I don't know what to try next as as far as I can tell I have followed Facebook's manual login guide as closely as possible.

Facebook login with multiple domains

I know that facebook allow me to specify multiple domains for my app.
But in the "Website with Facebook Login" i can only specify one url.
Is it possible for me, to authenticate users on domain.se, domain.dk and domain.net with the same App ? Or should i still create one app, for each domain ?
It is technically possible to use Facebook Connect on multiple domains, there are some limits (5 domains max).
So the key to doing this is adding all domains in the App Domain field under your app settings.
The PROBLEM, however, is that Facebook only lets you add domains that are derived from your Canvas URL or Site or Page tag URLs, so if you try to enter anything else you get an error that looks like this:
The SOLUTION is to create App on Facebook, Website, and Facebook Tab using the ADD PLATFORM button and then put in URLs that point to your other domains. Here is an example of what I mean:
If you use a unique domain for each field you can max out with 5 different domains. I have tested this technique with up to 3 domains, but i think it should work for all 5.
Note: Facebook admin features change from time to time, so all of this is subject to change
As long as you listed all the desired App Domains in application settings you should be able to authenticate users on any of them.
"Website with Facebook Login" is really only intended to be used as link to your site/application.
Update 2 (July 2016):
App domains must match the domain of the Secure Canvas URL, Mobile Site URL, Unity Binary URL, Site URL or Secure Page Tab URL.
Update (December 2013):
At the time of writing original answer it was possible to list any domains in application settings but from that time the UI of Application Settings (as well as way of handling Application Domains) changed at least couple of times, at some point you could only list domains that derive from one of application's canvas pages.
As of December 2013 it is possible (again) to list domains that do not derive from application canvas URL.
Assuming your domains are being served by the same web server and you have access to that web server, you can use the manual login procedure: https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow to login from as many domains as you wish.
Assume your domains are site1.com,site2.com.... Instead of using the Facebook javascript API, you will simply place a plain old Log In with Facebook button on each site which will redirect the browser to the facebook login page as described in the above article. In the state variable you can specify a code which indicates which of your sites is requesting a login. In the redirect you will use a single service domain which you assign to your web server (e.g. fb.mywebserver.com) and which you specify as the verified redirect url in the facebook login settings page. All the sites will redirect to this same url, avoiding the problem of supporting multiple domains.
Once the user has logged in, the browser will redirect to fb.mywebserver.com and pass it the state, which tells you which site is requesting login and a code which you can use on the back end to retrieve the user's info using the Facebook graph apis. You store this info with a uid in your data store then using the info in state, you redirect to to the appropriate site including a parameter that indicates a Facebook login (e.g. site1.com?fbc={some uid}). The browser will obediently then call site1.com?fbc... Your web server will receive this request and detect the fbc parameter which tells it to associate the corresponding Facebook logged in user with this site. It can then retrieve the logged in users info using the uid and, for example, return a session cookie for this user along with the page. If you generate the page on the server you can, of course, also include a welcome "user" or alternatively, your client code can do an ajax call to retrieve that information.
From the user's standpoint they press the Login with Facebook button, are redirected to a Facebook login page where they login and then are redirected back to your site in a logged in state. Not quite as nice as having the login popup but likely acceptable.
A similar process can be used for google logins as well
Best thing I've found to do in the development/production scenario is add a "Test App", then add a platform for your development web site - as you have to provide where the "page tab url" lives if you use that as a platform.
Facebook requires your "page url" to be live / accessible if you need to apply for status or permission review.
This got me around the "login in development" / "login in production" scenario.

Slow load facebook canvas app when click on links (if target top)

Situation: I am developing a facebook canvas app. Facebook is sending my sever a POST request with the signed_request each time that a page is render. Inside my app I have all my links with target="_top" because if I don't, facebook send my server a common GET without the signed request. So I cann't check the user info.
Problem: It is too slow! even if I am testing it in local, each click that I press takes 1 sec to render and my canvas becomes completely white and then the info is shown, It will be a bad user experience.
My tests: If I remove the target=_top and I point all my links' href to my server without the app.facebook.com/whatever, it loads very quickly.
My doubts: Is there any security issue with this? If I point all the links to my server (no apps.facebook.com) I can not check the signed request, I will only check it in the main page..
Any advice? any tutorial? Do I have any misundestanding of this? (It is my first facebook app)
Have you read the Server-Side Authentication tutorial?
You're doing it wrong.
Once the users lands in your app you should keep all links in the same frame, loading the entire window along with facebook is completely redundant.
What you should do:
When you get the POST with the signed request, decode it and check if the user is authenticated, if he is persist the data (token and such) somewhere (session, db, cache).
If he is not authenticated send him to the auth dialog as noted in the tutorial, when he gets back exchange the code you get (in GET) for the token (also shown in the tutorial), then redirect him to http(s)://apps.facebook.com/YOUR_APP and you'll be posted with the authenticated signed request, save it, etc..
Since you persist the data, in every request that is not POST or don't include the signed_request check your persistency choice for the data, and use it.
There should be only two times where facebook sends you the request, once it is POST when your canvas is loaded, the 2nd is when the user returns from the authentication dialog, in which you either get the code parameter or error in case the user declined the authentication.
Other requests should be from your app (inside the iframe) into the app servers.
JDL,
I believe you are querying the graph API at each request (and that's why you always need the signed_request). Is this right?
The graph API is pretty slow (~ 1 second/query) and you should use only when necessary. For example, when you first receive the access_token you should save it in your session and query the graph API to retrieve the respective facebook user info. But then you should put the info you need about this user in your session and only refresh it (using the graph API) when the signed_request access token is different from the one you have saved in your session.
The behavior of adding _top to the target of your links is ok and a good practice within facebook canvas.