Add "cost history" dialog for product view

older jquery theme only, for now

tailbone/views/products.py

@@ -1030,6 +1030,24 @@ class ProductsView(MasterView):
             grid.set_type('changed', 'datetime')
             kwargs['suggested_price_history_grid'] = grid
 
+            # cost history
+            data = self.get_cost_history(product)
+            grid = grids.Grid('products.cost_history', data,
+                              request=self.request,
+                              columns=[
+                                  'cost',
+                                  'vendor',
+                                  'since',
+                                  'changed',
+                                  'changed_by',
+                              ],
+                              labels={
+                                  'price_type': "Type",
+                              })
+            grid.set_type('cost', 'currency')
+            grid.set_type('changed', 'datetime')
+            kwargs['cost_history_grid'] = grid
+
         kwargs['costs_label_preferred'] = "Pref."
         kwargs['costs_label_vendor'] = "Vendor"
         kwargs['costs_label_code'] = "Order Code"
@@ -1289,6 +1307,58 @@ class ProductsView(MasterView):
 
         return list(final_history.values())
 
+    def get_cost_history(self, product):
+        """
+        Returns a sequence of "records" which corresponds to the given
+        product's cost history.
+        """
+        Transaction = continuum.transaction_class(model.Product)
+        ProductVersion = continuum.version_class(model.Product)
+        ProductCostVersion = continuum.version_class(model.ProductCost)
+        now = make_utc()
+        history = []
+
+        # we just find all relevant (preferred!) ProductCostVersion records
+        versions = self.Session.query(ProductCostVersion)\
+                               .join(Transaction,
+                                     Transaction.id == ProductCostVersion.transaction_id)\
+                               .filter(ProductCostVersion.product_uuid == product.uuid)\
+                               .filter(ProductCostVersion.preference == 1)\
+                               .order_by(Transaction.issued_at,
+                                         Transaction.id)\
+                               .all()
+
+        last_cost = None
+        last_vendor_uuid = None
+        for version in versions:
+
+            changed = False
+            if version.unit_cost != last_cost:
+                changed = True
+            elif version.vendor_uuid != last_vendor_uuid:
+                changed = True
+
+            if changed:
+                changed = version.transaction.issued_at
+                history.append({
+                    'transaction_id': version.transaction.id,
+                    'cost': version.unit_cost,
+                    'vendor': version.vendor.name,
+                    'since': humanize.naturaltime(now - changed),
+                    'changed': changed,
+                    'changed_by': version.transaction.user,
+                })
+
+            last_cost = version.unit_cost
+            last_vendor_uuid = version.vendor_uuid
+
+        final_history = OrderedDict()
+        for hist in sorted(history, key=lambda h: h['changed'], reverse=True):
+            if hist['transaction_id'] not in final_history:
+                final_history[hist['transaction_id']] = hist
+
+        return list(final_history.values())
+
     def edit(self):
         # TODO: Should add some more/better hooks, so don't have to duplicate
         # so much code here.