added sale price history

InvenTree/part/templates/part/prices.html

@@ -281,7 +281,15 @@
         </div>
         
         <div class='panel-content'>
-            PLACEHOLDER FOR SALE HISTORY
+            {% if sale_history|length > 0 %}
+                <div style="max-width: 99%; min-height: 300px">
+                    <canvas id="SalePriceChart"></canvas>
+                </div>
+            {% else %}
+                <div class='alert alert-danger alert-block'>
+                    {% trans 'No sale pice history available for this part.' %}
+                </div>
+            {% endif %}
         </div>
     </div>
 {% endif %}
@@ -444,4 +452,35 @@
         );
     {% endif %}
 
+    // Sale price history
+    {% if sale_history %}
+            var salepricedata = {
+                    labels: [
+                        {% for line in sale_history %}'{{ line.date }}',{% endfor %}
+                    ],
+                    datasets: [{
+                        label: '{% blocktrans %}Unit Price - {{currency}}{% endblocktrans %}',
+                        backgroundColor: 'rgba(255, 99, 132, 0.2)',
+                        borderColor: 'rgb(255, 99, 132)',
+                        yAxisID: 'y',
+                        data: [
+                            {% for line in sale_history %}{{ line.price|stringformat:".2f" }},{% endfor %}
+                        ],
+                        borderWidth: 1,
+                    },
+                    {
+                        label: '{% trans "Quantity" %}',
+                        backgroundColor: 'rgba(255, 206, 86, 0.2)',
+                        borderColor: 'rgb(255, 206, 86)',
+                        yAxisID: 'y1',
+                        data: [
+                            {% for line in sale_history %}{{ line.qty|stringformat:"f" }},{% endfor %}
+                        ],
+                        borderWidth: 1,
+                        type: 'bar',
+                    }]
+                }
+            var SalePriceChart = loadSellPricingChart($('#SalePriceChart'), salepricedata)
+    {% endif %}
+
 {% endblock %}

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):

InvenTree/templates/js/part.js

@@ -977,3 +977,36 @@ function loadBomChart(context, data) {
         }
     });
 }
+
+function loadSellPricingChart(context, data) {
+    return new Chart(context, {
+        type: 'line',
+        data: data,
+        options: {
+            responsive: true,
+            maintainAspectRatio: false,
+            plugins: {legend: {position: 'bottom'}},
+            scales: {
+                y: {
+                    type: 'linear',
+                    position: 'left',
+                    grid: {display: false},
+                    title: {
+                        display: true,
+                        text: '{% trans "Unit Price" %}'
+                    }
+                },
+                y1: {
+                    type: 'linear',
+                    position: 'right',
+                    grid: {display: false},
+                    titel: {
+                        display: true,
+                        text: '{% trans "Quantity" %}',
+                        position: 'right'
+                    }
+                },
+            },
+        }
+    });
+}