Refactor several "field grids" per Buefy theme

e.g. the Users field when viewing a Role, and Vendor Sources panel
when viewing a Product

tailbone/views/products.py

@@ -1152,8 +1152,88 @@ class ProductView(MasterView):
         kwargs['costs_label_vendor'] = "Vendor"
         kwargs['costs_label_code'] = "Order Code"
         kwargs['costs_label_case_size'] = "Case Size"
+
+        if use_buefy:
+            kwargs['vendor_sources'] = self.get_context_vendor_sources(product)
+            kwargs['lookup_codes'] = self.get_context_lookup_codes(product)
+
         return kwargs
 
+    def get_context_vendor_sources(self, product):
+        app = self.get_rattail_app()
+        route_prefix = self.get_route_prefix()
+
+        factory = self.get_grid_factory()
+        g = factory(
+            key='{}.vendor_sources'.format(route_prefix),
+            data=[],
+            columns=[
+                'preferred',
+                'vendor',
+                'vendor_item_code',
+                'case_size',
+                'case_cost',
+                'unit_cost',
+                'status',
+            ],
+            labels={
+                'preferred': "Pref.",
+                'vendor_item_code': "Order Code",
+            },
+        )
+
+        sources = []
+        link_vendor = self.request.has_perm('vendors.view')
+        for cost in product.costs:
+
+            source = {
+                'uuid': cost.uuid,
+                'preferred': "X" if cost.preference == 1 else None,
+                'vendor_item_code': cost.code,
+                'case_size': app.render_quantity(cost.case_size),
+                'case_cost': app.render_currency(cost.case_cost),
+                'unit_cost': app.render_currency(cost.unit_cost, scale=4),
+                'status': "discontinued" if cost.discontinued else "available",
+            }
+
+            text = six.text_type(cost.vendor)
+            if link_vendor:
+                url = self.request.route_url('vendors.view', uuid=cost.vendor.uuid)
+                source['vendor'] = tags.link_to(text, url)
+            else:
+                source['vendor'] = text
+
+            sources.append(source)
+
+        return {'grid': g, 'data': sources}
+
+    def get_context_lookup_codes(self, product):
+        route_prefix = self.get_route_prefix()
+
+        factory = self.get_grid_factory()
+        g = factory(
+            key='{}.lookup_codes'.format(route_prefix),
+            data=[],
+            columns=[
+                'sequence',
+                'code',
+            ],
+            labels={
+                'sequence': "Seq.",
+            },
+        )
+
+        lookup_codes = []
+        for code in product._codes:
+
+            lookup_codes.append({
+                'uuid': code.uuid,
+                'sequence': code.ordinal,
+                'code': code.code,
+            })
+
+        return {'grid': g, 'data': lookup_codes}
+
     def get_regular_price_history(self, product):
         """
         Returns a sequence of "records" which corresponds to the given