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

Add to your Gemfile:

gem 'omniauth-facebook'

Then bundle install.

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 a full example of both server and client-side flows in the example Sinatra app in the example/ folder above.

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,offline_access
• display: The display context to show the authentication page. Options are: page, popup, iframe, touch and wap. Read the Facebook docs for more details: http://developers.facebook.com/docs/reference/dialogs#display. Default: page

For example, to request email, offline_access 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,offline_access,read_stream', :display => 'popup'
end

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

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

{
  :provider => 'facebook',
  :uid => '1234567',
  :info => {
    :nickname => 'jbloggs',
    :email => '[email protected]',
    :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'
  },
  :credentials => {
    :token => 'ABCDEF...', # OAuth 2.0 access_token, which you may wish to store
    :expires_at => 1321747205, # when the access token expires (if it expires)
    :expires => true # if you request `offline_access` this will be false
  },
  :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 => '[email protected]',
      :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.

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.

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

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.

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