I want to write a Facebook Application that checks a user defined RSS feed periodically and import new items to users'/pages' wall(I know, there are similar apps). But I couldn't find an useful manual for authenticating for background processes. I mean, you know, I must publish streams when user not online. I know, a permission named "offline_access" for that, but I'm confused about that; do I have that I must store the access token key that I took while the user is online? Or are there any other method to using access token when user is offline?
Facebook API access tokens that taken with offline_access are long-lived tokens.(It's expires in 60 days). So yes, we must store access token key in our database but Facebook user must give access again in 60 days.
https://developers.facebook.com/roadmap/offline-access-removal/
Related
I would like to add a new option to my application that allows users to post images to their Facebook albums or on the wall. As of now, the most unclear point is how to organize authorizaton process in the DESKTOP application. Official documentation says that I can use short-lived or long-lived access tokens. There is no any issue with getting short-lived access tokens, but I want my application to ask a user for login/password rarely.
I see 2 possible options.
1) Use short-lived access tokens
When a previous token has expired, I need to ask Facebbok for a new one, but for that I need user's login/password.
Questions:
1.1) Is it a good idea to store and encrypt somewhere on disk user's login/password and to ask Facebook for a new short-lived access token using user's credentials in the background (i.e. user won't see login form - this is hidden) ?
1.2) Is it a good idea to store and encrypt short-lived access token on disk to reuse it if a user just restarted application and token is still valid?
2) Use long-lived access tokens
This would be ideal for me. Even if access token has expired after 60 days, my desktop app will ask for a new one.
Questions:
2.1) Is it possible to get long-lived access token by DESKTOP application directly from Facebook? Is it needed to implement additional Web service for getting such token (I know that just server (not client app) can add app secret to request for long-lived token)?
2.2) Even if I able to get long-lived token from the Facebook directly, is it a good idea to store and encrypt it somewhere on disk for further reusage? How apps usually story it?
I will appreciate any HELP!!!
Each user who allow permission to my app will have an access token
or
One access token can handle actions, for example, upload photos to an user album?
I know that an access token can expire up to 60 days,
so do I need save this access token for each user on my database and when request comes from that user, load the access token for him?
Each user who allow the app will have an access token, which will include all the permissions user has granted to your app.Read more about user access tokens here
Each user who allow permission to fb app, will have different Access Token which will be unique.
The Access Token is generated on the basis of browser session from client, AppID and App Secret. In a web server based application, it is not absolute requirement to save application token for user. But application like HootSuite saves user credentials and access token for later use to get facebook feeds and other services.
So it depends on application requirement.
Thanks
Each user sends you another access token in context to use User session of course.
An access token is a random string that provides temporary, secure
access to Facebook APIs.
A token identifies a User, App or Page session and provides
information about granted permissions.
And in User Access context:
You can use this token to perform API calls on behalf of a user,
including reading, publishing and deleting, depending on the
permissions your app has. For example, you can retrieve a user's
friend list or publish a new photo to their timeline with a user
access token.
http://developers.facebook.com/docs/concepts/login/access-tokens-and-types/
Yes, you have to remember this access token if you dont want to reconstruct it. But in many API's this is done "automagically", for e.x. in PHP SDK the access token is stored in user cookie. If you implement more complicated user-flow, you have to remember access token OR regenerate it each time (http://developers.facebook.com/docs/concepts/login/login-architecture/). Remember, that access token will expire and you will have to regenerate it (on the faith of already granted permissions).
FYI: If you want to preserver offline access (executing application activities without user session), you will consider offline_access, but it is deprecated:
http://developers.facebook.com/roadmap/offline-access-removal/
Hope it revealed the problem.
I'm making a facebook application that will scan a users' news feed on a daily basis - but the offline access token has been deprecated.
I know that the access token can be extended to 60 days. So if a user doesn't use my application for 60 days, would I be not able to access their information after that?
I read the developers section but didn't understand it properly.
That's exactly the point. You'll need to code your app to run through an authentication flow if the access token expires. Remember, the access token can expire for other (legitimate) reasons, other than timeout. If you're not asking for new permissions, and need to grab a new access tokens, the flow should happen without any user actions required.
You'll need to code for access tokens failing regardless of offline_access - so do it right! :)
What is access token in Facebook API?
why I need it ?
What is its purpose ?
Do I need to store it persistently in my website ?
For almost every request you make to facebook API you need to pass access token along to get the results. This token may expire depending on what kind it is, you might need to persist it in case your application need to access facebook API when user is offline.
PS: Access token comes from user's request to your application.
Facebook implementation of the OAuth 2.0 involves three different steps: user authentication, app authorization and app authentication. User authentication ensures that the user is who they say they are. App authorization ensures that the user knows exactly what data and capabilities they are providing to your app. App authentication ensures that the user is giving their information to your app and not someone else. Once these steps are complete, your app is issued an user access token that you enables you to access the user's information and take actions on their behalf.
access token will be expired unless the user has granted to your app the "offline_access" permission. In other word, unless you have such a perm granted, you don't need to store it persistently in your website.
I have been asked to look into whether or not I can retrieve a Facebook access token from Facebook if the user had granted permission in an earlier session. The problem is that our business logic tier is maintained by a different group and is on a different release schedule from the web development group. If I were to gain an offline access token, I might not be able to store it for up to two months. For any users acquired in the meantime, is there a way that I can retrieve the token from facebook without further intervention from the user?
I would think that this might be a security hole, but one of our senior developers thinks that it is likely that facebook offers such a feature.
Thanks,
Rob
In short No.
But with the offline access request being complete.
You can request a new token without any user clicking.
You just get a new offline access token and use that. The same way as if you didn't request offline access, and the access token had expired, it doesn't explicitly say but it does work:
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.
http://developers.facebook.com/docs/authentication/
That way you don't have to store them at all.
Unless you actually want to perform actions when the user is not using your Application.
You'll get the access_token every time the user logs back in, offline_access or not !
You can get it in JS with FB.getAccessToken();
There is no way to retrieve (offline) access token, when the user is not actually logged in.
If you want to store the access token for a long period of time, you will be required to ask for the offline_access permission, otherwise the access token will only last a short period of time. Either way, it is best to store it in a cookie or locally as it will certainly improve your app's latency. But make sure to check its validity as often as possible.
I think the access_token means, you have the permission to do things on behalf of the user. If you must do something without user FB login, you need the offline access_token. But be careful, the offline access_token will be ignored, when the user change his/her FB password, or delete the application.
So I hope there isn't any way to get another access_token without the user permission. I think the easiest way to check the access_token to make a /me?access_token= GET request, and check the answer. If the answer is an error, the access_token not working, you have to renew it.
To get access_token from somebody in the middle of the flow is a little pain. But you can also put variables to the redirect link.
Example:
https://graph.facebook.com/oauth/authorize?client_id=API_KEY&scope=email$redirect_uri=YOUR_REGISTERED_APP_URL%3F$param
$param could be a flow info like: flow=12342323
So when your user come back the $_GET['flow'] will be 12342323.