Part page loading improvements (#3185)

* Lazy load the pricing bom table when the "pricing" tab is selected

* Update django-debug-toolbar configuration

* Major refactoring for the 'can_build' function

- Use a single annotated query to the db, rather than a for loop (which is what a caveman would use)
- Query performance is greatly improved
- Also refactors existing variant-part-stock subquery code, to make it re-usable

* Use minified JS and CSS where possible

* Render a 'preview' version of each part image

- Saves load time when the image is quite large
- Adds a data migration to render out the new variation

* Adds 'preview' version of company images

* Defer loading of javascript files

Note: some cannot be deferred - jquery in particular

* Crucial bugfix for user roles context

- Previously was *not* being calculated correctly
- A non-superuser role would most likely display pages incorrectly

* Prevent loading of "about" on every page

- Load dynamically when requested
- Takes ~400ms!
- Cuts out a lot of fat

* Match displayed image size to preview image size

* Utilize caching framework for accessing user "role" information

- Reduces number of DB queries required by rendering framework

* Remove redundant query elements

* Remove 'stock' field from PartBrief serializer

- A calculated field on a serializer is a *bad idea* when that calculation requires a DB hit

* Query improvements for StockItem serializer

- Remove calculated fields
- Fix annotations

* Bug fixes

* Remove JS load test

- Loading of JS files is now deferred, so the unit test does not work as it used to

* Fix broken template for "maintenance" page

* Remove thumbnail generation migrations

- Already performed manually as part of ''invoke migrate"
- Running as a migration causes unit test problems
- Not sensible to run this as a data-migration anyway

* tweak for build table

InvenTree/stock/api.py

@@ -74,7 +74,6 @@ class StockDetail(RetrieveUpdateDestroyAPI):
         kwargs['part_detail'] = True
         kwargs['location_detail'] = True
         kwargs['supplier_part_detail'] = True
-        kwargs['test_detail'] = True
         kwargs['context'] = self.get_serializer_context()
 
         return self.serializer_class(*args, **kwargs)

InvenTree/stock/serializers.py

@@ -88,6 +88,12 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
     @staticmethod
     def annotate_queryset(queryset):
         """Add some extra annotations to the queryset, performing database queries as efficiently as possible."""
+
+        queryset = queryset.prefetch_related(
+            'sales_order',
+            'purchase_order',
+        )
+
         # Annotate the queryset with the total allocated to sales orders
         queryset = queryset.annotate(
             allocated=Coalesce(
@@ -136,20 +142,14 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
 
     location_detail = LocationBriefSerializer(source='location', many=False, read_only=True)
 
-    tracking_items = serializers.IntegerField(source='tracking_info_count', read_only=True, required=False)
-
     quantity = InvenTreeDecimalField()
 
-    allocated = serializers.FloatField(source='allocation_count', required=False)
-
+    # Annotated fields
+    tracking_items = serializers.IntegerField(read_only=True, required=False)
+    allocated = serializers.FloatField(required=False)
     expired = serializers.BooleanField(required=False, read_only=True)
-
     stale = serializers.BooleanField(required=False, read_only=True)
 
-    # serial = serializers.CharField(required=False)
-
-    required_tests = serializers.IntegerField(source='required_test_count', read_only=True, required=False)
-
     purchase_price = InvenTree.serializers.InvenTreeMoneySerializer(
         label=_('Purchase Price'),
         max_digits=19, decimal_places=4,
@@ -171,7 +171,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
         return str(obj.purchase_price) if obj.purchase_price else '-'
 
     purchase_order_reference = serializers.CharField(source='purchase_order.reference', read_only=True)
-
     sales_order_reference = serializers.CharField(source='sales_order.reference', read_only=True)
 
     def __init__(self, *args, **kwargs):
@@ -179,7 +178,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
         part_detail = kwargs.pop('part_detail', False)
         location_detail = kwargs.pop('location_detail', False)
         supplier_part_detail = kwargs.pop('supplier_part_detail', False)
-        test_detail = kwargs.pop('test_detail', False)
 
         super(StockItemSerializer, self).__init__(*args, **kwargs)
 
@@ -192,9 +190,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
         if supplier_part_detail is not True:
             self.fields.pop('supplier_part_detail')
 
-        if test_detail is not True:
-            self.fields.pop('required_tests')
-
     class Meta:
         """Metaclass options."""
 
@@ -208,7 +203,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
             'delete_on_deplete',
             'expired',
             'expiry_date',
-            'in_stock',
             'is_building',
             'link',
             'location',
@@ -222,7 +216,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
             'purchase_order_reference',
             'pk',
             'quantity',
-            'required_tests',
             'sales_order',
             'sales_order_reference',
             'serial',
@@ -249,7 +242,6 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
             'stocktake_date',
             'stocktake_user',
             'updated',
-            'in_stock'
         ]
 
 

InvenTree/stock/templates/stock/item_base.html

@@ -136,7 +136,7 @@
 {% endblock actions %}
 
 {% block thumbnail %}
-<img class='part-thumb' {% if item.part.image %}src="{{ item.part.image.url }}"{% else %}src="{% static 'img/blank_image.png' %}"{% endif %}/>
+<img class='part-thumb' {% if item.part.image %}src="{{ item.part.image.preview.url }}"{% else %}src="{% static 'img/blank_image.png' %}"{% endif %}/>
 {% endblock thumbnail %}
 
 {% block details %}