Potential fix for one of the issues mentioned in #49

Reduces the number of SQL queries used on group_orders/index and
group_orders/archive, but adds extra  complexity to the code

app/controllers/group_orders_controller.rb

@@ -9,6 +9,8 @@ class GroupOrdersController < ApplicationController
 
   # Index page.
   def index
+    @closed_orders_including_group_order = Order.closed.limit(5).ordergroup_group_orders_map(@ordergroup)
+    @finished_not_closed_orders_including_group_order = Order.finished_not_closed.ordergroup_group_orders_map(@ordergroup)
   end
 
   def new
@@ -56,6 +58,8 @@ class GroupOrdersController < ApplicationController
   def archive
     # get only orders belonging to the ordergroup
     @closed_orders = Order.closed.page(params[:page]).per(10)
+    @closed_orders_including_group_order = @closed_orders.ordergroup_group_orders_map(@ordergroup)
+    @finished_not_closed_orders_including_group_order = Order.finished_not_closed.ordergroup_group_orders_map(@ordergroup)
 
     respond_to do |format|
       format.html # archive.html.haml

app/models/order.rb

@@ -125,6 +125,20 @@ class Order < ApplicationRecord
     self
   end
 
+  # fetch current Order scope's records and map the current user's GroupOrders in (if any)
+  # (performance enhancement as opposed to fetching each GroupOrder separately from the view)
+  def self.ordergroup_group_orders_map(ordergroup)
+    orders = includes(:supplier)
+    group_orders = GroupOrder.where(ordergroup_id: ordergroup.id, order_id: orders.map(&:id))
+    group_orders_hash = Hash[group_orders.collect {|go| [go.order_id, go]}]
+    orders.map do |order|
+      {
+        order: order,
+        group_order: group_orders_hash[order.id]
+      }
+    end
+  end
+
   # search GroupOrder of given Ordergroup
   def group_order(ordergroup)
     group_orders.where(:ordergroup_id => ordergroup.id).first

app/views/group_orders/_orders.html.haml

@@ -6,8 +6,9 @@
       %th= heading_helper Order, :ends
       %th= heading_helper GroupOrder, :price
   %tbody
-    - for order in orders
+    - for order_hash in orders
-      - group_order = order.group_order(@ordergroup) # Get GroupOrder if possible
+      - order = order_hash[:order]
+      - group_order = order_hash[:group_order]
       - order_class = group_order ? "" : "color:grey"
       %tr{:class=> cycle('even', 'odd', :name => 'orders'), :style => order_class}
         %td= group_order.present? ? link_to(order.name, group_order_path(group_order)) : order.name

app/views/group_orders/archive.html.haml

@@ -5,9 +5,9 @@
 .row-fluid
   .span6
     %h2= t '.title_open'
-    = render :partial => "orders", :locals => {:orders => Order.finished_not_closed, :pagination => false}
+    = render partial: 'orders', locals: {orders: @finished_not_closed_orders_including_group_order, pagination: false}
 
   .span6
     %h2= t '.title_closed'
     #closed_orders
-      = render :partial => "orders", :locals => {:orders => @closed_orders, :pagination => true}
+      = render partial: 'orders', locals: {orders: @closed_orders_including_group_order, pagination: true}

app/views/group_orders/archive.js.haml

@@ -1 +1 @@
-$('#closed_orders').html('#{escape_javascript(render("orders", orders: @closed_orders, pagination: true))}');
+$('#closed_orders').html('#{escape_javascript(render("orders", orders: @closed_orders_including_group_order, pagination: true))}');

app/views/group_orders/index.html.haml

@@ -21,19 +21,19 @@
 = render :partial => "shared/open_orders", :locals => {:ordergroup => @ordergroup}
 
 // finished orders
-- unless Order.finished_not_closed.empty?
+- unless @finished_not_closed_orders_including_group_order.empty?
   %section
     %h2= t '.finished_orders.title'
-    = render :partial => "orders", :locals => {:orders => Order.finished_not_closed, :pagination => false}
+    = render partial: 'orders', locals: {orders: @finished_not_closed_orders_including_group_order, pagination: false}
     - if @ordergroup.value_of_finished_orders > 0
       %p
         = t('.finished_orders.total_sum') + ':'
         %b= number_to_currency(@ordergroup.value_of_finished_orders)
 
 // closed orders
-- unless Order.closed.empty?
+- unless @closed_orders_including_group_order.empty?
   %section
     %h2= t '.closed_orders.title'
-    = render :partial => "orders", :locals => {:orders => Order.closed.limit(5), :pagination => false}
+    = render partial: 'orders', locals: {orders: @closed_orders_including_group_order, pagination: false}
     %br/
     = link_to t('.closed_orders.more'), archive_group_orders_path

spec/models/order_spec.rb

@@ -83,4 +83,21 @@ describe Order do
 
   end
 
+  describe 'mapped to GroupOrders' do
+    let!(:user) { create :user, groups: [create(:ordergroup)] }
+    let!(:order) { create :order }
+    let!(:order2) { create :order }
+    let!(:go) { create :group_order, order: order, ordergroup: user.ordergroup }
+
+    it 'to map a user\'s GroupOrders to a list of Orders' do
+      orders = Order.ordergroup_group_orders_map(user.ordergroup)
+
+      expect(orders.length).to be 2
+      expect(orders[0][:order]).to have_attributes(id: order.id)
+      expect(orders[0][:group_order]).to have_attributes(id: go.id)
+      expect(orders[1][:order]).to have_attributes(id: order2.id)
+      expect(orders[1][:group_order]).to be_nil
+    end
+  end
+
 end