npm package: @jackdeng/passport-facebook
Description: Facebook authentication strategy for Passport.
Author: JackDeng666
Latest version: 1.0.1

# passport-facebook

[Passport](https://www.passportjs.org/) strategy for authenticating with [Facebook](https://www.facebook.com/)
using [OAuth 2.0](https://www.passportjs.org/features/oauth2/).

This module lets you authenticate using Facebook in your Node.js applications.
By plugging into Passport, Facebook Login can be easily and unobtrusively
integrated into any application or framework that supports
[Connect](https://github.com/senchalabs/connect#readme)-style middleware,
including [Express](https://expressjs.com/).

<div align="center">

:seedling: [Tutorial](https://www.passportjs.org/tutorials/facebook/?utm_source=github&utm_medium=referral&utm_campaign=passport-facebook&utm_content=nav-tutorial) •
:brain: [Understanding OAuth 2.0](https://www.passportjs.org/concepts/oauth2/?utm_source=github&utm_medium=referral&utm_campaign=passport-facebook&utm_content=nav-concept) •
:heart: [Sponsors](https://www.passportjs.org/sponsors/?utm_source=github&utm_medium=referral&utm_campaign=passport-facebook&utm_content=nav-sponsors)

</div>

<div align="right">
  <sup>Developed by <a href="#authors">Jared Hanson</a>.</sub>
</div>

---

<div align="center">
  <sup>Advertisement</sup>
  <br>
  <a href="https://click.linksynergy.com/link?id=D*o7yui4/NM&offerid=507388.922484&type=2&murl=https%3A%2F%2Fwww.udemy.com%2Fcourse%2Fthe-complete-nodejs-developer-course-2%2F&u1=1zlZ1AkoVQjosKoeCqb9osAgjkpQyUiZEQGmEc4SfB4OV">The Complete Node.js Developer Course</a><br>Learn Node. js by building real-world applications with Node, Express, MongoDB, Jest, and more!
</div>

---

## Install

```sh
$ npm install passport-facebook
```

## Usage

#### Register Application

The Facebook strategy authenticates users using their Facebook account.  Before
your application can make use of Facebook's authentication system, you must
first [register](https://developers.facebook.com/docs/development/create-an-app)
your app.  Once registered, an app ID and secret will be issued which are used
by Facebook to identify your app.  You will also need to configure a redirect
URI which matches the route in your application.

#### Configure Strategy

Once you've [registered your application](#register-application), the strategy
needs to be configured with your application's app ID and secret, along with
its OAuth 2.0 redirect endpoint.

The strategy takes a `verify` function as an argument, which accepts
`accessToken`, `refreshToken`, and `profile` as arguments.  `accessToken` and
`refreshToken` are used for API access, and are not needed for authentication.
`profile` contains the user's [profile information](https://www.passportjs.org/reference/normalized-profile/)
stored in their Facebook account.  When authenticating a user, this strategy
uses the OAuth 2.0 protocol to obtain this information via a sequence of
redirects and API requests to Facebook.

The `verify` function is responsible for determining the user to which the
Facebook account belongs.  In cases where the account is logging in for the
first time, a new user record is typically created automatically.  On subsequent
logins, the existing user record will be found via its relation to the Facebook
account.

Because the `verify` function is supplied by the application, the app is free to
use any database of its choosing.  The example below illustrates usage of a SQL
database.

```js
var FacebookStrategy = require('passport-facebook');

passport.use(new FacebookStrategy({
    clientID: process.env['FACEBOOK_APP_ID'],
    clientSecret: process.env['FACEBOOK_APP_SECRET'],
    callbackURL: 'https://www.example.com/oauth2/redirect/facebook',
    state: true
  },
  function verify(accessToken, refreshToken, profile, cb) {
    db.get('SELECT * FROM federated_credentials WHERE provider = ? AND subject = ?', [
      'https://www.facebook.com',
      profile.id
    ], function(err, cred) {
      if (err) { return cb(err); }
      
      if (!cred) {
        // The account at Facebook has not logged in to this app before.  Create
        // a new user record and associate it with the Facebook account.
        db.run('INSERT INTO users (name) VALUES (?)', [
          profile.displayName
        ], function(err) {
          if (err) { return cb(err); }
          
          var id = this.lastID;
          db.run('INSERT INTO federated_credentials (user_id, provider, subject) VALUES (?, ?, ?)', [
            id,
            'https://www.facebook.com',
            profile.id
          ], function(err) {
            if (err) { return cb(err); }
            
            var user = {
              id: id,
              name: profile.displayName
            };
            return cb(null, user);
          });
        });
      } else {
        // The account at Facebook has previously logged in to the app.  Get the
        // user record associated with the Facebook account and log the user in.
        db.get('SELECT * FROM users WHERE id = ?', [ cred.user_id ], function(err, user) {
          if (err) { return cb(err); }
          if (!user) { return cb(null, false); }
          return cb(null, user);
        });
      }
    });
  }
));
```

#### Define Routes

Two routes are needed in order to allow users to log in with their Facebook
account.  The first route redirects the user to the Facebook, where they will
authenticate:

```js
app.get('/login/facebook', passport.authenticate('facebook'));
```

The second route processes the authentication response and logs the user in,
after Facebook redirects the user back to the app:

```js
app.get('/oauth2/redirect/facebook',
  passport.authenticate('facebook', { failureRedirect: '/login', failureMessage: true }),
  function(req, res) {
    res.redirect('/');
  });
```

## Examples

* [todos-express-facebook](https://github.com/passport/todos-express-facebook)

  Illustrates how to use the Facebook strategy within an Express application.  For
  developers new to Passport and getting started, a [tutorial](https://www.passportjs.org/tutorials/facebook/)
  is available.

* [todos-express-facebook-popup](https://github.com/passport/todos-express-facebook-popup)

  Illustrates how to use progressive enhancement to display the the Facebook
  login dialog in a popup window.  State is kept during the OAuth 2.0 flow and
  used to close the window for requests using that display mode.

## FAQ

##### How do I ask a user for additional permissions?

If you need additional permissions from the user, the permissions can be
requested via the `scope` option to `passport.authenticate()`.

```js
app.get('/auth/facebook',
  passport.authenticate('facebook', { scope: ['user_friends', 'manage_pages'] }));
```

Refer to [permissions with Facebook Login](https://developers.facebook.com/docs/facebook-login/permissions/overview)
for further details.

##### How do I re-ask for for declined permissions?

Set the `authType` option to `reauthenticate` when authenticating.

```js
app.get('/auth/facebook',
  passport.authenticate('facebook', { authType: 'reauthenticate', scope: ['user_friends', 'manage_pages'] }));
```

Refer to [re-asking for declined permissions](https://developers.facebook.com/docs/facebook-login/web#re-asking-declined-permissions)
for further details.

##### How do I obtain a user profile with specific fields?

The Facebook profile contains a lot of information about a user.  By default,
not all the fields in a profile are returned.  The fields needed by an application
can be indicated by setting the `profileFields` option.

```js
new FacebookStrategy({
  clientID: FACEBOOK_APP_ID,
  clientSecret: FACEBOOK_APP_SECRET,
  callbackURL: "http://localhost:3000/auth/facebook/callback",
  profileFields: ['id', 'displayName', 'photos', 'email']
}), ...)
```

Refer to the [User](https://developers.facebook.com/docs/graph-api/reference/v2.5/user)
section of the Graph API Reference for the complete set of available fields.

##### How do I include app secret proof in API requests?

Set the `enableProof` option when creating the strategy.

```js
new FacebookStrategy({
  clientID: FACEBOOK_APP_ID,
  clientSecret: FACEBOOK_APP_SECRET,
  callbackURL: "http://localhost:3000/auth/facebook/callback",
  enableProof: true
}, ...)
```

As detailed in [securing graph API requests](https://developers.facebook.com/docs/graph-api/securing-requests#appsecret_proof),
requiring the app secret for server API requests helps prevent use of tokens
stolen by malicous software or man in the middle attacks.

##### Why is #\_=\_ appended to the redirect URI?

This behavior is "by design" according to Facebook's response to a [bug](https://developers.facebook.com/bugs/318390728250352)
filed regarding this issue.

Fragment identifiers are not supplied in requests made to a server, and as such
this strategy is not aware that this behavior is exhibited and is not affected
by it.  If desired, this fragment can be removed on the client side.  Refer to
this [discussion](http://stackoverflow.com/questions/7131909/facebook-callback-appends-to-return-url) on
Stack Overflow for recommendations on how to accomplish such removal.

## Authors

- [Jared Hanson](https://www.jaredhanson.me/) { [![WWW](https://raw.githubusercontent.com/jaredhanson/jaredhanson/master/images/globe-12x12.svg)](https://www.jaredhanson.me/) [![Facebook](https://raw.githubusercontent.com/jaredhanson/jaredhanson/master/images/facebook-12x12.svg)](https://www.facebook.com/jaredhanson) [![LinkedIn](https://raw.githubusercontent.com/jaredhanson/jaredhanson/master/images/linkedin-12x12.svg)](https://www.linkedin.com/in/jaredhanson) [![Twitter](https://raw.githubusercontent.com/jaredhanson/jaredhanson/master/images/twitter-12x12.svg)](https://twitter.com/jaredhanson) [![GitHub](https://raw.githubusercontent.com/jaredhanson/jaredhanson/master/images/github-12x12.svg)](https://github.com/jaredhanson) }

## License

[The MIT License](http://opensource.org/licenses/MIT)

Copyright (c) 2011-2023 Jared Hanson