#645 Enable account creation or authorisation from a facebook signin (and should work for others with minimal extra work)

app/controllers/omniauth_callbacks_controller.rb

@@ -0,0 +1,90 @@
+#
+# Handle signup or signin
+# from various oauth providers
+#
+# Heavily overlaps with Authentications controller
+#
+class OmniauthCallbacksController < Devise::OmniauthCallbacksController
+  def facebook
+    create
+  end
+  def failure
+    redirect_to request.env['omniauth.origin'] || "/", :flash => {:error => ":("}
+  end
+
+  private
+
+  #
+  # Inspects the omniauth information
+  # and determines if we have an existing member 
+  # (to add authentication to)
+  # or if this is a new signup
+  #
+  # As a side affect, this method sets the @member_created
+  # variable
+  #
+  def member
+    @member_created = false
+
+    auth = request.env['omniauth.auth']
+
+    authentication = Authentication.where(provider: auth.provider, uid: auth.uid).first
+    if authentication && authentication.member.id.present?
+      member = authentication.member
+    end
+
+    Member.where(email: auth.info.email).first_or_create do |m|
+      m.email = auth.info.email
+      m.password = Devise.friendly_token[0,20]
+      m.tos_agreement = true
+      m.login_name = Devise.friendly_token[0,20] # TODO: A better login name to generate
+
+      # m.name = auth.info.name   # assuming the user model has a name
+      # m.image = auth.info.image # assuming the user model has an image
+      @member_created = true
+    end
+    
+    member
+  end
+
+  def create
+    auth = request.env['omniauth.auth']
+    @authentication = nil
+    if auth
+
+      name = ''
+      case auth['provider']
+      when 'twitter'
+        name = auth['info']['nickname']
+      when 'flickr', 'facebook'
+        name = auth['info']['name']
+      else
+        name = auth['info']['name']
+      end
+
+      @authentication = member.authentications
+      .create_with(
+        :name => name,
+        :token => auth['credentials']['token'],
+        :secret => auth['credentials']['secret'],
+      )
+      .find_or_create_by(
+        :provider => auth['provider'],
+        :uid => auth['uid'],
+        :name => name,
+        :member_id => member.id
+      )
+
+      unless @member_created
+        sign_in_and_redirect member, :event => :authentication #this will throw if @user is not activated
+        set_flash_message(:notice, :success, :kind => auth['provider']) if is_navigational_format?
+      else
+        session["devise.#{auth['provider']}_data"] = request.env["omniauth.auth"]
+        redirect_to new_member_registration_url
+      end
+    else
+      flash[:notice] = "Authentication failed."
+      redirect_to request.env['omniauth.origin'] || edit_member_registration_path
+    end
+  end
+end

config/initializers/devise.rb

@@ -231,5 +231,5 @@ Devise.setup do |config|
   # When using omniauth, Devise cannot automatically set Omniauth path,
   # so you need to do it manually. For the users scope, it would be:
   # config.omniauth_path_prefix = "/my_engine/users/auth"
-  config.omniauth :facebook, ENV['GROWSTUFF_FACEBOOK_KEY'], ENV['GROWSTUFF_FACEBOOK_SECRET'], :scope => 'email', :display => 'popup'
+  config.omniauth :facebook, ENV['GROWSTUFF_FACEBOOK_KEY'], ENV['GROWSTUFF_FACEBOOK_SECRET'], :scope => 'email,read_stream', :display => 'page', :info_fields => 'nickname,email,name'
 end

config/routes.rb

@@ -4,7 +4,7 @@ Growstuff::Application.routes.draw do
 
   resources :plant_parts
 
-  devise_for :members, :controllers => { :registrations => "registrations", :passwords => "passwords" }
+  devise_for :members, :controllers => { :registrations => "registrations", :passwords => "passwords", :omniauth_callbacks => "omniauth_callbacks" }
   devise_scope :member do 
     get '/members/unsubscribe/:message' => 'members#unsubscribe', :as => 'unsubscribe_member'
   end