a simple controller to allow user sign in and sign in w/ Facebook and google

user_sessions_controller.rb

class UserSessionsController < ApplicationController
  skip_before_filter :require_login, :only => [:new, :create, :authenticate]
    
  rescue_from User::NotActivated do |e|
    flash.now.alert = "You are not activted"
    render :not_activated
  end

  rescue_from User::InvalidPassword do |e|
    flash.now.alert = "Invalid email or password"
    render :new
  end

  rescue_from User::EmptyPassword do |e|
      redirect_to new_password_reset_url, :notice => "Password Empty. Please fill out the form below to set up a password."
  end

  def new
    # Set proper redirect url for ajax requests.
    # It is probably better to store the :return_to hash by request type
    session[:return_to] = request.referer unless ( request.referer.nil? || request.referer.include?("password_resets"))# Sets
    redirect_to dashboard_users_path if current_user
   end
  
  def create
    @user = User.find_by_email(params[:email])
    if @user && @user.authenticate_user(params[:password])
      store_remember_me
      session[:user_id] = @user.id
      @user.increase_login_count
      @user.update_ip(request)
      respond_to do |format|
        format.html { redirect_back_or_default(dashboard_users_path) }
        format.json { render :json => @user.to_json }
      end
    else
       raise User::InvalidPassword 
    end
  end
  
  def authenticate
    omniauth = request.env["omniauth.auth"]
    authentication = Account.find_by_account_type_and_uid(omniauth['provider'], omniauth['uid'])
    if authentication
      session[:user_id] = authentication.user.id
      authentication.user.increase_login_count
      authentication.user.update_ip(request)
      redirect_back_or_default(dashboard_users_path)
    else
      user = User.find_by_email(omniauth['info']['email'])
      if user
        session[:user_id] = user.id
        user.accounts.create(:account_type => omniauth['provider'], :uid => omniauth['uid'], :credentials => {:token => omniauth['credentials']['token']})
        user.increase_login_count
        user.update_ip(request)
        redirect_back_or_default(dashboard_users_path)
      else
        user = User.new
        if user.apply_omniauth(omniauth)
          session[:user_id] = user.reload.id
          redirect_back_or_default(dashboard_users_path) 
        else
          session[:omniauth] = omniauth['info']
          redirect_to sign_up_path, :notice => "Hi #{omniauth['info']['first_name']}, Please fill out the missing fields to finish sign up."
        end
      end
    end
  end

  def destroy
    remove_remember_me
    reset_session
    redirect_to sign_in_path, :notice => "Signed out!"
  end
  
  private
  
    def store_remember_me
      cookies.permanent[:auth_token] = @user.auth_token if params[:remember_me]
    end
    
    def remove_remember_me
      cookies.delete(:auth_token)
    end
  

end