cache payment_method and can now set paypal's landing page by setting allow_guest_checkout

app/controllers/spree/checkout_controller_decorator.rb

@@ -226,7 +226,7 @@ module Spree
 
     # hook to override paypal site options
     def paypal_site_opts
-      {:currency => payment_method.preferred_currency}
+      {:currency => payment_method.preferred_currency, :allow_guest_checkout => payment_method.preferred_allow_guest_checkout }
     end
 
     def order_opts(order, payment_method, stage)
@@ -362,7 +362,7 @@ module Spree
 
     # create the gateway from the supplied options
     def payment_method
-      Spree::PaymentMethod.find(params[:payment_method_id])
+      @payment_method ||= Spree::PaymentMethod.find(params[:payment_method_id])
     end
 
     def paypal_gateway

app/models/spree/billing_integration/paypal_express.rb

@@ -5,9 +5,9 @@ class Spree::BillingIntegration::PaypalExpress < Spree::BillingIntegration
   preference :review, :boolean, :default => false
   preference :no_shipping, :boolean, :default => false
   preference :currency, :string, :default => 'USD'
+  preference :allow_guest_checkout, :boolean, :default => false
 
   def provider_class
     ActiveMerchant::Billing::PaypalExpressGateway
   end
-
 end

spec/controllers/checkout_controller_spec.rb

@@ -6,7 +6,7 @@ module Spree
     let(:order) { Factory(:ppx_order_with_totals, :state => "payment") }
     let(:order_total) { (order.total * 100).to_i }
     let(:gateway_provider) { mock(ActiveMerchant::Billing::PaypalExpressGateway) }
-    let(:paypal_gateway) { mock(BillingIntegration::PaypalExpress, :id => 123, :preferred_review => false, :preferred_no_shipping => true, :provider => gateway_provider, :preferred_currency => "US"
+    let(:paypal_gateway) { mock(BillingIntegration::PaypalExpress, :id => 123, :preferred_review => false, :preferred_no_shipping => true, :provider => gateway_provider, :preferred_currency => "US", :preferred_allow_guest_checkout => true
     ) }
 
     let(:details_for_response) { mock(ActiveMerchant::Billing::PaypalExpressResponse, :success? => true,
@@ -289,5 +289,14 @@ module Spree
 
 
     end
+
+    describe "#paypal_site_opts" do
+      it "returns opts to allow guest checkout" do
+        controller.should_receive(:payment_method).at_least(1).and_return(paypal_gateway)
+
+        opts = controller.send(:paypal_site_opts)
+        opts[:allow_guest_checkout].should be_true
+      end
+    end
   end
 end