Add "scheduled_for_deletion" field to StockItem

- If set to True, this StockItem will be deleted (soon) by the background worker
- As deletion takes significant time, this prevents delete operations from blocking the UI

InvenTree/stock/api.py

@@ -653,6 +653,9 @@ class StockList(generics.ListCreateAPIView):
 
         queryset = StockItemSerializer.annotate_queryset(queryset)
 
+        # Do not expose StockItem objects which are scheduled for deletion
+        queryset = queryset.filter(scheduled_for_deletion=False)
+
         return queryset
 
     def filter_queryset(self, queryset):

InvenTree/stock/migrations/0066_stockitem_scheduled_for_deletion.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.4 on 2021-09-07 06:27
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0065_auto_20210701_0509'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitem',
+            name='scheduled_for_deletion',
+            field=models.BooleanField(default=False, help_text='This StockItem will be deleted by the background worker', verbose_name='Scheduled for deletion'),
+        ),
+    ]

InvenTree/stock/models.py

@@ -209,7 +209,8 @@ class StockItem(MPTTModel):
         belongs_to=None,
         customer=None,
         is_building=False,
-        status__in=StockStatus.AVAILABLE_CODES
+        status__in=StockStatus.AVAILABLE_CODES,
+        scheduled_for_deletion=False,
     )
 
     # A query filter which can be used to filter StockItem objects which have expired
@@ -588,6 +589,12 @@ class StockItem(MPTTModel):
                               help_text=_('Select Owner'),
                               related_name='stock_items')
 
+    scheduled_for_deletion = models.BooleanField(
+        default=False,
+        verbose_name=_('Scheduled for deletion'),
+        help_text=_('This StockItem will be deleted by the background worker'),
+    )
+
     def is_stale(self):
         """
         Returns True if this Stock item is "stale".