How to publish to a feed if you have offline_access permission - facebook-graph-api

I am trying to publish to a user's FB account, and I have the following permissions:
* offline_access
* publish_stream
But when I try to post to the user's account, it appears that FB is asking me for an access token (which I don't have).
Does anyone know the structure of the URL to publish to a FB user's stream when you don't have an access token?
Thanks

Do an HTTP POST to /userID/feed?access_token=appID|appSecret

You need to have your app login. About 2/3rds of the way down on the authentication documentation, there are instructions on how to get a session access token for your app.
https://developers.facebook.com/docs/authentication/
Basically, just hit this url:
https://graph.facebook.com/oauth/access_token?
client_id=YOUR_APP_ID&client_secret=YOUR_APP_SECRET&
grant_type=client_credentials
And you will get back an access token you can use to post to any user's wall that your app has permission for.

Related

Facebook Messenger subscribed apps, page and app access token generation

I am hitting a wall while developing seamless integration of a Facebook page with my bot.
Essentially I want to achieve same integration than Chatfuel or Manychat have, where being logged in with your Facebook account lets you to just choose what page you are connecting to them and you are good to go.
The problem I am facing is generating the proper token in order to bind the selected page to my app (bot). As per Facebook documentation:
When you create a subscribed_apps edge, the page-id you use in endpoint must match the page ID of the page access token used in the API call. The app that the access token is for is installed for the page.
Given the call has no other parameter than the access token, this access token has to be enough for Facebook to:
Authorize the action on the page.
Identify what app is being subscribed to the page.
This is confirmed while using the Facebook Graph API Explorer, where one selects the page and the app to bind and a proper access token is generated:
This token properly works using cURL in the terminal:
$ curl -X POST 'https://graph.facebook.com/v3.0/<MY_APP_ID_HERE>/subscribed_apps?access_token=<TOKEN_PASTED_FROM_GRAPH_API_EXPLORER>'
{"success":true}
With the Facebook Access token debugger (info icon on the left of the access token, then open in Access token tool), it is confirmed that the token knows about both the page and the app that have to be connected.
The question is, how are these page-app related token programmatically produced? I can't seem to find the proper API call in Facebook documentation and it is by all means possible, as Chatfuel and Manychat are doing this.
Thanks in advance for your support Lars Schwarz and community!
Adding some detail to Alex's answer, for it to be more complete.
When subscribing an app to a page, Facebook needs to:
Know what app you are talking about.
Know what page you are talking about.
Know that you have permissions on that page to subscribe an app.
How does Facebook know it all?
1 comes from the fact that Facebook login happens in the context of a page, actually, the Javascript code for Facebook contains your appId:
js.src = 'https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v3.0&appId=<YOUR_APP_ID_IS_HERE>&autoLogAppEvents=1';
2 Comes from the page_id in the URL used to subscribe apps to pages:
https://graph.facebook.com/v3.0/YOUR_APP_ID_HERE/subscribed_apps?access_token=YOUR_ACCESS_TOKEN_HERE
3 Comes from the access token, obtained in the context of an APP through Facebook login, that is passed as parameter in the URL used to subscribe apps to pages:
https://graph.facebook.com/v3.0/YOUR_APP_ID_HERE/subscribed_apps?access_token=YOUR_ACCESS_TOKEN_HERE
To do this, you need to put FB Login on your site/customer portal and request pages_messaging and manage_pages permissions. The person that logs in must be a Page Admin.
Once your app has been granted that permission for the page, you can generate a page access token as described here:
https://developers.facebook.com/docs/pages/access-tokens

Fb Graph API - want to publish without manually logging each time using Java

I logged-in to facebook manually, creating accesstoken, logged out.
Tried to publish in my timeline using my java app, I got
java.lang.Exception: {"error":{"message":"Error validating access token: The session is invalid because the user logged out.","type":"OAuthException","code":190,"error_subcode":467}}
I've ticked the check box for publish_stream and offline_access at least while creating access token.
How could I publish in my timeline without getting logged manually each time.
The offline_access is deprecated.
The most easy way is to use page token because this is an unlimited session token.
See there how to get it : Facebook Access Token for Pages

working with facebook Graph API

I was reading about FB Graph API in this page. Please see the section Authorization
They say that
At a high level, you need to get an
access token for the Facebook user.
I am confused. How do i get the logeed in users access token in my website
https://developers.facebook.com/docs/reference/api/
You don't get a logged in user's access token. Once a user is authenticated, you receive an access token to be able to see/manipulate that user's data, depending on what permissions you have requested from that user.
This is well documented in the "Authentication" section of the developer documentation: https://developers.facebook.com/docs/authentication/

Facebook API get user accesstoken for app

I am posting to my facebook wall through my app using my user.
I gave to the app offline access but still, sometimes the accesstoken changes.
I would like to know if its possible to use Facebook API to get the accesstoken?
Right now, I used the example.php from the facebook sdk to login and took the accesstoken from there.
again, I dont want the application accesstoken. I want to user accesstoken of using the app.
Thanks.
There is App Login section in Authorization paragraph in https://developers.facebook.com/docs/reference/api/ .
Read it. You have to call it if you get invalid access token error in order to refresh the token. However, sometimes the token is invalid due to lack of permissions and not because the token is expired

When adding Facebook integration to a web app, how do you handle OAuth token expiration and what user data should be saved?

I'm planning out adding Facebook integration to a web app I'm working on. For the most part, it's proceeding smoothly, but I am confused on the proper way to handle the OAuth token.
The sequence of events presented by Facebook here is:
Ask the user to authorize your application, which sends them to a Facebook window.
This will return an Authorization Code generated by Facebook
You then hit https://graph.facebook.com/oauth/access_token with your Authorization Code, which will give you a time-limited OAuth token.
Using the OAuth token, you can make requests to access the user's Facebook profile.
Facebook's documentation has the following to say about token expiration:
In addition to the access token (the access_token parameter), the response contains the number of seconds until the token expires (the expires parameter). Once the token expires, you will need to re-run the steps above to generate a new code and access_token, although if the user has already authorized your app, they will not be prompted to do so again. If your app needs an access token with an infinite expiry time (perhaps to take actions on the user's behalf after they are not using your app), you can request the offline_access permission.
When they say to re-run the steps above, what steps need to be re-run to get a new OAuth token? What data (Facebook UID, Authorization Code, OAuth token) does it make sense to save to my local database?
I would like to be able to have the user continue to interact with my site, and in response to certain user actions, I would like to be able to prompt to user if they want to post something to their Facebook wall.
The access token is time and session based and is unnecessary data to store and have no use after the user have closed the session.
The facebook uid is the only thing you need to identify the user.
Since the Facebook API sometimes is horrible slow you could store the username aswell.
But for identification, all you need is the uid.
The documentation that facebook provides has been updated since you asked this question. https://developers.facebook.com/docs/authentication/.