Facebook

Register your app in Meta's Developer Dashboard

To use the Facebook Provider you will need a client id and a client secret. You will get them while following the process to setup Facebook OAuth 2.0 for your application. Follow the instructions in the following link:

info

When asked for an origin URL, insert the origin of the url in which your app is hosted.

Examples:

• http://localhost:3000
• https://www.example.com

When asked for a redirect URL (or callback), insert[http or https]://[origin]/[your route for Facebook authentication]

Examples:

• http://localhost:8000/auth/facebook
• https://www.example.com/api/login/facebook
• https://www.example.com/godel/russell/myFacebookLogin

Easy-to-read article (Follow the guide until you get a client id and client secret and setup a callback. Don't worry about the rest, Gatekeeper will take care of that): https://theonetechnologies.com/blog/post/how-to-get-facebook-application-id-and-secret-key

Facebook Provider

Options

Option name	Description	Default value	Required?
clientId	Your Facebook OAuth client id		Yes
clientSecret	Your Facebook OAuth client secret		Yes
callbackURL	The URL that will serve as callback for Facebook OAuth		Yes
scope	The OAuth scopes that will be granted to the access token	['public_profile', 'email']	No

danger

To the callbackURL option you must provide the URL you provided when asked for a redirect (or callback) URL when registering your Facebook OAuth app.

Handler

The Facebook Provider passes three parameters to the handler:

• refresh_token: The OAuth refres token. It is usually only given the first time a user signs-in to your application
• access_token: The OAuth access token.
• profile: The information of the Facebook user.

Errors

The predefined errors of this provider are:

• UserNotFound

Examples

Example #1

Create a Facebook Provider

import gatekeeper from 'gatekeeper-authentication'
import { FacebookProvider } from 'gatekeeper-authentication/providers/facebook' 

const FacebookAuth = new FacebookProvider({
    clientId: '<YOUR FACEBOOK CLIENT ID>',
    clientSecret: '<YOUR FACEBOOK CLIENT SECRET>',
    callbackURL: 'https://yourdomainorlocalhost.com/auth/facebook'
}, function handler(refresh_token, access_token, profile) => {
    const user = User.findOne({ facebookId: profile.id })
    
    if (user == null) {
        // For example, if the user does not exist, create it
        User.create({
            username: profile.name,
            email: profile.email
        });
    }
    
    return user;
});

Login with a Facebook Provider

warning

Important: When using the Facebook provider on login routes, make sure you use gatekeeper.authenticateWithProvider(yourFacebookProvider) in a GET route, as the user will be redirected to Facebook's sign in page

router.get(
    '/auth/facebook',
    gatekeeper.authenticateWithProvider(FacebookAuth), (req, res) => {
        return res.redirect('/profile');
    }
);