Am I allowed to create an app that only invited people can join?
Or do all apps have to be open to everyone?
You can have a white list for people who are allowed to use your app in your database and ignore any request for other people.
EDIT:
As per the question in the comment section, I will give you more details. I have not quite done exactly this, but I can guarantee you this is possible. I have a website, linked to Facebook and people can log in to the site using Facebook. In my database I am storing the Facebook ID and the Facebook user access token. When a user clicks on the login with Facebook, his Facebook user access token is checked against the database. If the Facebook user access token (which works like a temporary password) expires, it is renewed. However, people are identified by their Facebook ID. I could easily have a white list for Facebook IDs and allow access only for people whose Facebook ID can be found in the database. My project strategy is to get as many users as possible, but I could easily modify this to restrict access for not verified people. Your problem with consistent login probably lies in the fact that the Facebook user access token expires in a few hours. However, that problem is solvable:
if the user has modified his Facebook password, or has not connected to the app, then he will be asked by Facebook for permissions
if the user is no longer logged in, then he will have to log in
if the user's Facebook user access token has expired, then you should generate a new Facebook user access token
finally, you can generate long-term Facebook user access tokens, which last for months.
Read the documentation for details, but keep in mind that things might have been changed at Facebook since the documentation was written, therefore you should not believe everything written there, but should rather test the validity of the most important statements.
Related
I'm trying to figure out a core concept in FB that even after reading a lot of FB documentation, couldn't understand.
Let's say I'm building an app (that will reside in a tab), in which I want to see the last post of a user. I want to do this approximately one month after the user approved my app, without him using the app again.
I assume I will need to use a long-lived expiration token that will be saved to my DB.
A month after I will run a procedure that will use this token and check the user posts.
Is this correct?
What about a situation in which the user logged out? The token is no longer valid.. does this mean I will never be able to access user posts unless he will access my app?
Isn't this a bit weird (since he already approved my app)?
Not necessarily.
Firstly, you need the read_stream permission from the user when they authenticate your app. Then, because you are intending to use Facebook as the app, rather than as the user, you need to authenticate as an app, which is a simple process:
In order to get an access token for the app, all you need to do is use the following URL:
https://graph.facebook.com/oauth/access_token?client_id=YOUR_APP_ID&client_secret=YOUR_APP_SECRET&grant_type=client_credentials
Because these tokens are time-limited, it may be easier to request a token each time you use the Graph API, rather than storing it in a database and waiting for it to expire.
Then, all you need to do is use the following request:
https://graph.facebook.com/USER_ID/feed?access_token=YOUR_ACCESS_TOKEN
The upside to this is that it does not matter whether or not the user is logged into Facebook.
See here for more details:
https://developers.facebook.com/docs/authentication/applications/
I'm aware that there are many questions about Facebook access-tokens and the grief they cause, but despite much experimentation and reading many frustratingly vague blog articles (FB and otherwise), I'm still struggling to get a clear answer to my needs. Let me succinctly break down my process so far:
I am creating a site that, server-side, needs to pull the posts/statuses from a single Facebook Page
I am an admin of that Facebook Page
I have created a Facebook App
Using the Facebook Graph API Explorer, I've generated a short-lived key, connected to my app and my account, that grants permission to my account to view the access-tokens for my pages
I've converted my short-lived key to a long-lived key (60 days) ala scenario 4 from this
And here's where I am stuck. My 60 day key works fine for my server to pull the info needed from the page, but as far I can tell, there's no way to programmatically extend that 60 day key. I also do not know of a way to generate a new short-lived key without manually going to the Facebook Graph API Explorer and creating one.
Since it is my server making the requests to the Facebook API and not a user-based system (where I could easily request that a user authorize the Facebook app again), this creates a very clunky system. Since Facebook deprecated offline_access, is there really no permanent way to have my server pull info from my own page? Will I really have to create a new key by hand and manually update my server with it every 60 days?
Or is there something I'm missing?
Update:
The step-by-step guide that was previously found here has been migrated down into its own answer.
These are the steps that were previously in the question - they have been migrated to this answer.
Having found that it is possible to generate a Facebook Page Access Token that does not expire (with help from #Igy), here is a clear, step-by-step quide for all those looking to the same:
Make sure you are the admin of the FB page you wish to pull info from
Create a FB App (should be with the same user account that is the page admin)
Head over to the Facebook Graph API Explorer
On the top right, select the FB App you created from the "Application" drop down list
Click "Get Access Token"
Make sure you add the manage_pages permission
Convert this short-lived access token into a long-lived one by making this Graph API call:
https://graph.facebook.com/oauth/access_token?client_id=<your FB App ID >&client_secret=<your FB App secret>&grant_type=fb_exchange_token&fb_exchange_token=<your short-lived access token>
Grab the new long-lived access token returned back
Make a Graph API call to see your accounts using the new long-lived access token: https://graph.facebook.com/me/accounts?access_token=<your long-lived access token>
Grab the access_token for the page you'll be pulling info from
Lint the token to see that it is set to Expires: Never!
That should do it. You should now have a Facebook Page Access Token that doesn't expire, unless:
You change your Facebook account password
You lose admin access for the target page
You delete or de-authorize your Facebook App
Any of these will cause the access token to become invalid.
If you are getting (#100) Tried accessing nonexisting field (accounts) on node type (Page), go to the Access Token Debugger, copy the value of User ID, and use it to replace the "me" part of the URL in step 9.
This is covered in the Offline Access deprecation document
Use the 60-day token for the page admin to retrieve a Page Access Token (via /PAGE_ID?fields=access_token or /me/accounts) - the Page access token will not have an expiry time
An approach that works in 2019
I was recently trying to achieve something similar (to the use case described in this thread), but I wanted to make sure to respect Facebook's current policies, so I did a little research and here I'm sharing what I found.
My use case
So, as I said already, my use case is very similar to the one described here; that is:
I'm doing some work for a school district.
They are using a software tool to manage pretty much everything that relates to school transportation.
That tool allows them to send email notifications (to subscribers) when they publish bus delay alerts and school closure alerts.
A lot of people in the community follow the organization on their Facebook page, and that's the only place they look for those alerts.
So an employee of the organization has to manually publish each notification on the Facebook page (in addition to creating it in the transportation software). Moreover, those notifications eventually expire (or are simply deleted before they expire), so the employee has to go back later on to delete them manually as well.
It's a waist of time, so what we are trying to do here is to develop as simple system that periodically polls the software tool's database for new (and expired) notifications and update them (i.e. add and remove) on the Facebook page.
This is, in my view, a legitimate use case, but I wasn't sure how to implement it in a way that's in line with Facebook's policies.
The accepted answer
I followed the steps of the accepted answer and it worked, except that things appear to have changed: now, even though the generated page token does not expire, access to data does expire after around 60 days. You will see that as well if you follow the procedure and inspect the page token in the FB Token Debugger Tool.
Besides, the fact that the generated page tokens are tied to the user account is also unfortunate, because if the user updates his/her password, then the page token also gets invalidated.
How to do it in 2019
After several hours of research, I stumbled upon the following Facebook documentation article: Business Login for Direct Businesses.
It turns out that it is now possible, following the steps described in the above article, to generate a page token that is not associated to any particular Facebook user account and which will not expire (unless the FB App gets deleted or the underlying application token gets deleted, you know...)
So here are the steps and the most important parts:
You need a Business Manager account.
Verification will be required and a digital contract will have to be signed.
You need to add the target Facebook page to that account.
You need to create a Facebook App, and transfer that app to the same Business Manager account as well.
The app will have to go through Facebook's review process, because the following permissions will be needed: manage_pages and publish_pages.
Important note For the posts made using the generate page token to be visible to users other than the application administrators, that app will need to have been published and approved.
You may still experiment with the concept without submitting for review, but the posts won't be publicly visible.
In the Business Manager account (only after your app and page have been added to the account), you need to create what's called a System User, and give that user admin role (or permissions) to the target Facebook page.
A system user is owned by the Business Manager account, and isn't tied to a specific user. My current understanding is that one major use case for a system user is programmatic access to Facebook's Graph API (just what we need).
Then, for that system user, you need to generate a access token (which will be never-expiring). You will be prompted to select for which app. You will then select your target app.
You will then need to use the generated app token to generate a page token, which will also be never-expiring. The procedure is described in this article as:
GET /<PAGE_ID>?fields=access_token&access_token=<SYSTEM_USER_ACCESS_TOKEN>
That's it.
That token will never expire, and it won't be tied to a particular Facebook user, so it's exactly what we need!
The last part is to make sure that your Facebook app gets approved by Facebook. It's in fact the most important part, because the whole procedure is worthless if people don't see our posts.
I wanted to know for sure that I could rely on the above procedure to build something for my client without Facebook rejecting it in the end, so, beforehand (i.e. before starting to work on my client's project), I went through the whole process of creating a page, an app, a Business Manager account, etc. I verified my business. I submitted my app for review. In my request, I was very specific about my use case and emphasized that the app was for "self-use" (i.e. that the organization is developing an app for itself, not for other Facebook users). I got approved without less than 24 hours.
A few other notes about the app review process:
I had to select a platform for the app, so I selected website.
I had to indicate why the app needed the two permissions and how it was going to use them.
I had to indicate why the reviewer would not be able to sign into my app and try it (i.e. because the app will be used by a worker process).
For the mandatory screencasts, I simply presented manual operations in the terminal using the curl utility (to generate the page token and make posts to the Facebook page). I also showed how I was using Business Manager to link the system user to the page and generate a token, and so on.
Again, I was very specific about my use case, and I think that that helped.
I hope this information will be useful to people with similar use cases.
Many thanks to #redhotvengeance for step-by-step guide.
After some time, now there is clearly described in Facebook documentation:
https://developers.facebook.com/docs/facebook-login/access-tokens/expiration-and-extension
Extending Page Access Tokens
Apps can retrieve a page access token from Page admin users when they
authenticate with the manage_pages permission. If the user access
token used to retrieve this page access token is short-lived, the page
access token will also be short-lived.
To get a longer-lived page access token, exchange the User access
token for a long-lived one, as above, and then request the Page access
token. The resulting page access token will not have any expiry time.
You can also copy and past from the app dashboard on facebook.
The steps:
Go to https://developers.facebook.com
Select your app in the top right corner of the page
(pic of what it looks like)
Click on Messenger from the options on the left (it will go to setting automatically) (pic of what it looks like)
Go to the "Token Generation" section in the page. Select what page you want to generate the token for. (pic of what that section looks like)
The copy and past your page token where ever you need it.
Keep in mind that while in theory your token won't expire, that it is directly tied to what ever facebook account your logged into. So say you change your password or you remove the permissions from between your account and your app then your token won't be valid any more.
I'm trying to implement facebook connect to my website, and i have couple questions.
1: Is it possible to register user in my website using his current facebook email/password.
Let's say user clicks on link Register via facebook and then he have to give me permisions to access his password, email, etc... and after that is done i put that info in my own database and he will be able to login with that account any time he wants without needing to give me permisions any time in the future.
2: If that kind of registration is not possible, what's other solution would be the best for me? Because i need to somehow keep track of that user who logged in with facebook, because he can upload photos, send messages etc.
Anyways, i'm quite new with facebook and similar things, so i'm really lost here, hope some one can help me :)
EDIT Thank you all for wonderful answers it helped me a lot, now all that's left is to read documentation :)
Yes it is, it is possible to get the information of the user. But it is rather complicated, when you have never dealt with it.
First you need to send the user to the following link:
https://m.facebook.com/dialog/oauth?client_id=your-client-id&redirect_uri=xxx&scope=listof-information-you-want
Facebook will then return your client to the uri specified, if the user rejected it will give a reason. If it is not you will get an code in urlencoded format.
This code is needed for the following step, the request of the access token:
https://graph.facebook.com/oauth/access_token?redirect_uri=xxx&client_id=xxx&client_secret=xxx&code=xxxx
This will give back an access token, if the authorization didn't fail.
After that you can ask for the information you want:
https://graph.facebook.com/me?method=GET&metadata=true&format=json&access_token=access_token
This will include a facebook uid, which is unique for all users. Store it and you can discern between a register and login.
This is roughly the process for any oauth2 application.
Facebook will not ask repeatedly for permissions after the user granted them to you. So you can store the access token and reuse it for backend stuff and also use the same procedure you use for register for login.
You can never access the user's password from Facebook even with his/her permission, so the user will always have to authenticate via Facebook and have Facebook pass you the user id of the logged in user once authentication succeeds. You can store all kinds of other data locally, but not enough to authenticate the user yourself.
Once the user is authenticated, you'll have access to the user's Facebook user id via the API, which should be enough to connect all kinds of information to that specific user.
Facebook does not provide access to accounts when passwords are taken from your controls. It provides it own canvas for login information. Therefore you cannot use your first approach to store passwords in your databases. Check this out.
You can however store email addresses once user logins into his account using the facebook sdks. Check this out link for the example of C# SDK sample code.
You can use the Facebook APIs to fetch user email-id, photos, friendslist and other information and then play around accordingly.
You don't get access to the users password - only email if you ask for it.
Best way would be to have a table of users and their Facebook account id's.
If you want to allow users to sign up without Facebook then have a nullable field for their password and facebook id, and also have a field for username - which you could populate from Facebook if they register via that route.
As mentioned in this other question, if a user grants the publish_stream permission, I can publish to that user's wall using an app access_token. I tested that and it works. But I couldn't publish to the user's pages using the app access_token! Am I missing something?
Right now I use the /me/accounts/ connection to get the access_token of the pages, and use that to publish. But this is a huge headache for me and for users because these tokens expire often (when users change their password, ...et), and every time that happens the publish fails and I need to email the user to come login again so I can retrieve a new access_token for the page. It's a bad user experience and I'm trying to find a way around it. The app token works for publishing to users, which is great, but I couldn't find a way to make it work for pages. Any tips?
Edit:
To clarify further, I currently request the manage_pages and offline_access permissions, and then fetch the access_token of each page and use that to publish to it. That works. The main problem is that tokens expire, even with the offline_access permission. The most common reason a token would expire is if the user changes her password. Here is a common error that I get a lot when publishing to Facebook pages.
Facebook error. type: OAuthException, message: 'Error validating
access token: Session does not match current stored session. This may
be because the user changed the password since the time the session
was created or Facebook has changed the session for security reasons.'
To handle this, I email the user and ask them to visit our app again, and when they do I grab a fresh set of access_token to work with. But that's problematic because users are confused about why the error happened and blame us for it, and some users don't open their emails so the problem doesn't get solved and then they're angry later when they discover that our app had stopped weeks ago without them asking it to stop.
That's why I was hoping that I can publish with the app access_token to avoid these problems. Since it works for user profiles, I hoped it would work for pages as well. But so far no luck, unless I'm missing something obvious.
What you're describing used to work - all last year we were able to successfully post to fan page walls using the app access token. In fact, for some of our users, I see it still working. However, I think the other two answers are correct, this is no longer the way to post to pages (see "Page Login" here)
That said, you should be able to store the access token of the page to spare yourself the step of re-querying the users' linked accounts.
Unfortunately, the page's access token will suffer the same fragility as a user's, per the answer here: Facebook Page Access Tokens - Do these expire? . The page access token will expire when the user who gave you that access token changes their password.
To publish to pages, there is an extra step where you use their token to get a list of their pages. Each page has its own token, use that token to post to the page. Keep in mind that when setting up the original token, you need to specify that you need access to pages.
my app does exactly what you're after.
I request both manage_pages and offline_access permissions from a user.
I store the user's access_token.
I ask the user which page (determined by me/accounts) they want a stream item posted to and when.
Later, when it is time to publish to a page's feed, I grab the user's access_token from the database, the pageid, and the message.
Using that user's access token, I query the me/accounts and grab the latest access token for that account (aka page)
Using that page's access token, I me/feed (or is it me/posts...away from my codebase at the moment) post the stream item.
If you have a web application that will allow the users to opt-in to sharing their activity on Facebook and Twitter I'm wondering what is the right way to architect that social authentication into your application (and what is inline with Facebook and Twitter policies) so that you can tweet and post on your wall.
Do you store the users username and password in your database?
And then call the social APIs with these credentials. From what I have learned so far both these APIs make you do an OAuth redirect thing. Is their a way to do that without the dialog interaction since you now have stored the username and password anyways.
Not sure if this is an issue, but do you have to do two OAuth handshakes one right after the next to post to Facebook and then Twitter for those users that want to share on both.
And would you have to do this each and every time the user shares something?
I just launched TweetDeck and I wasn't required to get redirected through some exchange with Twitter. Confused.
Just need some help and guidance with "how most people do it" for web-based applications.
The less prompting and less redirects the better.
I don't think storing the username and password would be a good way to go since I think most users would object to you keeping thiere usernames and passwords on file. I have not done any work with Twitter, but on Facebook you need to create an App and then ask the user to grant your app rights. These rights require the user to be loged in to Facebook in order to work, unless you request the offline_access permmission. From my experience, the fewer permmissions you request, the more users will be willing to grant you these permmissions. My approach is to always request the minimal permmissions I need to get the App to work. After granting your App permmissions, you need to get an OAuth token each time you want to interact with the user's Facebook account. (These tokens are good for about 60 minutes, as far as I remember) Storing these tokens will not help, since they expire. Hope this points you in the right direction.