Developers of third-party apps now have the option to provide two modes of Facebook Login to their users: Classic mode and Limited Login mode, designed to give users an option to restrict the data shared.
The new version of Facebook Login can be implemented by updating Facebook iOS SDK or Facebook SDK for Unity to version 9.0+. The update seems to be in response to the upcoming iOS privacy changes that may limit the user data shared with Facebook if the user chooses to.
Facebook Logins are integrated by app developers into their platforms to give users the option to sign in to their app with Facebook credentials, without going through the creation and verification process required for making a new account for these apps.
This includes the 'Sign-in With Facebook' or 'Sign-In With Google' options you might've come across while using an app or a platform. Developers integrate the ability to use Facebook Login for two purposes - authentication of the user and to access their Facebook data for personalization.
It also allows developers to retain the users who might drop away from the platform if they do not want to go through the process of creating a new account. The functionality is available for iOS, Android, Web, desktop apps, and devices such as Smart TVs.
The two new login modes:
This mode remains unchanged from the present mode, which grants access to the Facebook user data to the app by allowing the user to access existing accounts or create new ones. Classic Login mode utilizes an oAuth 2.0 Access Token which supports Graph API queries.
Based on the OpenID Connect standard, the Limited Login mode enables users to access existing accounts or create new ones while only sharing their name, profile pic, and (optionally) email address. Limited Login mode utilizes a JSON Web Token which does not support Graph API queries.
Developers can choose either of the two modes uniformly for all users or in a way that is subjected to one or more conditions, depending on if the user gives consent to sharing data and ads personalization.
The developers can also change the users' login mode at any time. This means if a user initially chose to not share data and later chooses to share data, the developer can provide the Classic Login mode for their following session.
This change will give them access to more user data as opposed to only name, email, and profile picture, while complying with the user permissions and changing preferences.