Using mobile_fu

application_controller_mobile_only.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  has_mobile_fu false

  protected
  
  def mobile_only_mobile_fu
    set_mobile_format if is_mobile_device?
  end
end

application_controller_spec.rb

  describe "mobile_fu" do
    it "responds to is_mobile_device?" do
      controller.should respond_to(:is_mobile_device?)
    end

    it "responds to is_tablet_device?" do
      controller.should respond_to(:is_tablet_device?)
    end

    describe "#mobile_only_mobile_fu" do
      before { controller.stub(:mobile_exempt? => false) }

      it "should not set the mobile_view session if tablet_device" do
        controller.stub(:is_tablet_device? => true)
        controller.send(:mobile_only_mobile_fu)
        session[:mobile_view].should be_nil
      end

      it "should set the mobile_view session if mobile_device" do
        controller.stub(:is_mobile_device? => true)
        controller.send(:mobile_only_mobile_fu)
        session[:mobile_view].should == true
      end

      it "should not set the mobile_view session if no device" do
        controller.send(:mobile_only_mobile_fu)
        session[:mobile_view].should be_nil
      end
    end
  end

application_controller_tablet_and_mobile.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  has_mobile_fu false
end

offers_controller_mobile_only.rb

class OffersController < ApplicationController
  before_filter :mobile_only_mobile_fu, only: :show
end

offers_controller_spec.rb

      context "when mobile or table device" do
        it "sets mobile_view if mobile_device" do
          controller.stub(:is_mobile_device? => true)
          get :show, offer: offer
          session[:mobile_view].should be_true
        end

        it "doesn't set tablet_view if table_device" do
          controller.stub(:is_tablet_device? => true)
          get :show, offer: offer
          session[:tablet_view].should_not be_true
        end
      end

offers_controller_tablet_and_mobile.rb

class OffersController < ApplicationController
  has_mobile_fu true
  has_no_mobile_fu_for :index
end