added sale price history

InvenTree/part/views.py

@@ -50,6 +50,7 @@ import common.settings as inventree_settings
 
 from . import forms as part_forms
 from .bom import MakeBomTemplate, BomUploadManager, ExportBom, IsValidBOMFormat
+from order.models import PurchaseOrderLineItem
 
 from .admin import PartResource
 
@@ -1038,6 +1039,36 @@ class PartPricingView(PartDetail):
             # add to global context
             ctx['bom_parts'] = ctx_bom_parts
 
+        # Sale price history
+        sale_items = PurchaseOrderLineItem.objects.filter(part__part=part).order_by('order__issue_date').\
+            prefetch_related('order', ).all()
+
+        if sale_items:
+            sale_history = []
+
+            for sale_item in sale_items:
+                # check for not fully defined elements
+                if None in [sale_item.purchase_price, sale_item.quantity]:
+                    continue
+
+                price = convert_money(sale_item.purchase_price, default_currency)
+                line = {
+                    'price': price.amount if price else 0,
+                    'qty': sale_item.quantity,
+                }
+
+                # set date for graph labels
+                if sale_item.order.issue_date:
+                    line['date'] = sale_item.order.issue_date.strftime('%d.%m.%Y')
+                elif sale_item.order.creation_date:
+                    line['date'] = sale_item.order.creation_date.strftime('%d.%m.%Y')
+                else:
+                    line['date'] = _('None')
+
+                sale_history.append(line)
+
+            ctx['sale_history'] = sale_history
+
         return ctx
 
     def get_initials(self):