Display calculator in payment method edit form

app/controllers/spree/admin/payment_methods_controller_decorator.rb

@@ -57,6 +57,7 @@ module Spree
         else
           @providers = Gateway.providers.reject{ |p| p.name.include? "Bogus" }.sort{|p1, p2| p1.name <=> p2.name }
         end
+        @calculators = PaymentMethod.calculators.sort_by(&:name)
       end
 
       def load_hubs

app/overrides/spree/admin/payment_methods/_form/replace_form_fields.html.haml.deface

@@ -33,4 +33,8 @@
       = radio_button :payment_method, :active, false
        
       = label_tag nil, t(:say_no)
-  = render 'providers'
+  = render 'providers'
+
+  .row
+    .omega.eleven.columns
+      = render partial: 'spree/admin/shared/calculator_fields', :locals => { :f => f }

config/application.rb

@@ -34,6 +34,11 @@ module Openfoodnetwork
                                                       Spree::Calculator::PerItem,
                                                       Spree::Calculator::PriceSack,
                                                       OpenFoodNetwork::Calculator::Weight]
+      app.config.spree.calculators.payment_methods = [Spree::Calculator::FlatPercentItemTotal,
+                                                      Spree::Calculator::FlatRate,
+                                                      Spree::Calculator::FlexiRate,
+                                                      Spree::Calculator::PerItem,
+                                                      Spree::Calculator::PriceSack]
     end
 
     # Register Spree payment methods

config/initializers/spree.rb

@@ -40,9 +40,7 @@ module Spree
   module Core
     class Environment
       class Calculators
-        include EnvironmentExtension
-
-        attr_accessor :enterprise_fees
+        attr_accessor :enterprise_fees, :payment_methods
       end
     end
   end