Prompt for clear cart when order cycle changes

app/assets/javascripts/darkswarm/directives/change_order_cycle.js.coffee

@@ -0,0 +1,19 @@
+Darkswarm.directive "ofnChangeOrderCycle", (OrderCycle, Cart, storage) ->
+  # Compares chosen order cycle with pre-set OrderCycle. Will trigger
+  # a confirmation if they are different, and Cart isn't empty
+  restrict: "A"
+  scope: true
+  link: (scope, elm, attr)->
+    order_cycle_id = ->
+      parseInt elm.val()
+
+    cart_needs_emptying = ->
+      OrderCycle.order_cycle?.order_cycle_id && OrderCycle.order_cycle.order_cycle_id != order_cycle_id() && !Cart.empty()
+
+    elm.bind 'change', (ev)->
+      if cart_needs_emptying()
+        if confirm "Are you sure? This will change your selected order cycle and remove any items in your shopping cart."
+          Cart.clear()
+          scope.changeOrderCycle()
+      else
+        scope.changeOrderCycle()

app/views/enterprises/shop.html.haml

@@ -16,7 +16,7 @@
       / Will this label should be a variable to reflect 'Ready for pickup / delivery' as appropriate
 
       %select.avenir#order_cycle_id{"ng-model" => "order_cycle.order_cycle_id",
-              "ng-change" => "changeOrderCycle()",
+              "ofn-change-order-cycle" => true,
               "ng-options" => "oc.id as oc.time for oc in #{@order_cycles.map {|oc| {time: pickup_time(oc), id: oc.id}}.to_json}",
               "popover-placement" => "left", "popover" => "Choose when you want your order:", "popover-trigger" => "openTrigger"}