Building OAuth Strategies with passport.js Chapter 7// Handle facebook login
}));
};In the preceding code, the first line inside the exports method imports the Facebook
Strategy. The configuration takes three parameters: clientID, clientSecret, and
callback URL. clientID and clientSecret are the App ID and App Secret for your
Facebook app, respectively.
Let's add those secrets into our config file. In config/Config.js, let's add our Facebook
keys, the facebook_client_id and facebook_client_secret:
module.exports = {
DB: 'mongodb://localhost/movie_rating_app',
SECRET: 'movieratingappsecretkey',
FACEBOOK_APP_ID: <facebook_client_id>,
FACEBOOK_APP_SECRET: <facebook_client_secret>
}The callback URL is the URL that you want to route your application to after the successful
transaction with Facebook.
The callback we have defined here is
http://127.0.0.1:8081/login/facebook/return, which we have to define. The
configuration is followed by a function that takes the following four parameters:
accessToken
refreshToken
profile
cb (callback)Upon successful request, our application will get redirected to the home page.
Adding necessary routes for Facebook login
Now, let's go ahead and add the necessary routes for when we click on the login button and
when we receive the callback from Facebook. In the same file, facebook.js, add the
following routes:
const User = require("../models/User");
const passport = require('passport');
const config = require('./../config/Config');