OmniAuth Facebook  

Facebook OAuth2 Strategy for OmniAuth 1.0.

Supports the OAuth 2.0 server-side and client-side flows. Read the Facebook docs for more details: http://developers.facebook.com/docs/authentication

Edge: Also supports authentication for Facebook app pages/canvas, via parsing the signed request. Take a look at the example Sinatra app for how to integrate with a canvas page.

Installing

Add to your Gemfile:

gem 'omniauth-facebook'

Then bundle install.

Usage

OmniAuth::Strategies::Facebook is simply a Rack middleware. Read the OmniAuth 1.0 docs for detailed instructions: https://github.com/intridea/omniauth.

Here's a quick example, adding the middleware to a Rails app in config/initializers/omniauth.rb:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook, ENV['FACEBOOK_KEY'], ENV['FACEBOOK_SECRET']
end

See the example Sinatra app for full examples of both the server and client-side flows (including using the Facebook Javascript SDK).

Configuring

You can configure several options, which you pass in to the provider method via a Hash:

• scope: A comma-separated list of permissions you want to request from the user. See the Facebook docs for a full list of available permissions: http://developers.facebook.com/docs/reference/api/permissions. Default: email
• display: The display context to show the authentication page. Options are: page, popup and touch. Read the Facebook docs for more details: https://developers.facebook.com/docs/reference/dialogs/oauth/. Default: page
• secure_image_url: Set to true to use https for the avatar image url returned in the auth hash. Default is false.
• image_size: Set the size for the returned image url in the auth hash. Valid options are square (50x50), small (50 pixels wide, variable height), normal (100 pixels wide, variable height), or large (about 200 pixels wide, variable height). Default is square (50x50).

For example, to request email, user_birthday and read_stream permissions and display the authentication page in a popup window:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook, ENV['FACEBOOK_KEY'], ENV['FACEBOOK_SECRET'],
           :scope => 'email,user_birthday,read_stream', :display => 'popup'
end

Per-Request Options

If you want to set the display format or scope on a per-request basis, you can just pass it to the OmniAuth request phase URL, for example: /auth/facebook?display=popup or /auth/facebook?scope=email.

You can also pass through a state param which will be passed along to the callback url.

Custom Callback URL/Path

You can set a custom callback_url or callback_path option to override the default value. See OmniAuth::Strategy#callback_url for more details on the default.

Authentication Hash

Here's an example Authentication Hash available in request.env['omniauth.auth']:

{
  :provider => 'facebook',
  :uid => '1234567',
  :info => {
    :nickname => 'jbloggs',
    :email => 'joe@bloggs.com',
    :name => 'Joe Bloggs',
    :first_name => 'Joe',
    :last_name => 'Bloggs',
    :image => 'http://graph.facebook.com/1234567/picture?type=square',
    :urls => { :Facebook => 'http://www.facebook.com/jbloggs' },
    :location => 'Palo Alto, California',
    :verified => true
  },
  :credentials => {
    :token => 'ABCDEF...', # OAuth 2.0 access_token, which you may wish to store
    :expires_at => 1321747205, # when the access token expires (it always will)
    :expires => true # this will always be true
  },
  :extra => {
    :raw_info => {
      :id => '1234567',
      :name => 'Joe Bloggs',
      :first_name => 'Joe',
      :last_name => 'Bloggs',
      :link => 'http://www.facebook.com/jbloggs',
      :username => 'jbloggs',
      :location => { :id => '123456789', :name => 'Palo Alto, California' },
      :gender => 'male',
      :email => 'joe@bloggs.com',
      :timezone => -8,
      :locale => 'en_US',
      :verified => true,
      :updated_time => '2011-11-11T06:21:03+0000'
    }
  }
}

The precise information available may depend on the permissions which you request.

Client-side Flow

The client-side flow supports parsing the authorization code from the signed request which Facebook puts into a cookie. This means you can to use the Facebook Javascript SDK as you would normally, and you just hit the callback endpoint (/auth/facebook/callback by default) once the user has authenticated in the FB.login success callback.

See the example Sinatra app under example/ for more details.

Supported Rubies

Actively tested with the following Ruby versions:

• MRI 1.9.3
• MRI 1.9.2
• MRI 1.8.7
• JRuby 1.6.5

NB. For JRuby, you'll need to install the jruby-openssl gem. There's no way to automatically specify this in a Rubygem gemspec, so you need to manually add it your project's own Gemfile:

gem 'jruby-openssl', :platform => :jruby

License

Copyright (c) 2011 by Mark Dodwell

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.