single method for updating cart item state / fixed problems with sinatra contrib

front-api/controllers/cart.rb

@@ -21,10 +21,9 @@ get '/cart/item' do
   Cart.find_or_create(anonymous_id, -1).item_in_carts.to_json
 end
 
-post '/cart/item/add' do
-  #cart_id = Cart.find_or_create(anonymous_id, -1).id
-  #item_id = params[:id].to_i
-  #ItemInCart.add(cart_id, item_id)
-  #json_params.to_json
-  "not ready yet".to_json
+post '/cart/item' do
+  cart_id = Cart.find_or_create(anonymous_id, -1).id
+  item_id = @json_params["item_id"]
+  count = @json_params["count"]
+  ItemInCart.update_state(cart_id, item_id, count).to_json
 end