Adds "shipped" field to SalesOrderLineItem

- This is an internal tracker of quantity of items shipped
- Updated by the database logic (not by the user)
- Keeps track of how many items have been shipped against a lineitem
- Does not matter if the actual stock items are later removed from the database

InvenTree/order/migrations/0057_salesorderlineitem_shipped.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.2.5 on 2021-11-26 12:06
+
+import InvenTree.fields
+import django.core.validators
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('order', '0056_alter_salesorderallocation_shipment'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='salesorderlineitem',
+            name='shipped',
+            field=InvenTree.fields.RoundingDecimalField(decimal_places=5, default=0, help_text='Shipped quantity', max_digits=15, validators=[django.core.validators.MinValueValidator(0)], verbose_name='Shipped'),
+        ),
+    ]

InvenTree/order/migrations/0058_auto_20211126_1210.py

@@ -0,0 +1,62 @@
+# Generated by Django 3.2.5 on 2021-11-26 12:10
+
+from django.db import migrations
+
+from InvenTree.status_codes import SalesOrderStatus
+
+
+def calculate_shipped_quantity(apps, schema_editor):
+    """
+    In migration 0057 we added a new field 'shipped' to the SalesOrderLineItem model.
+
+    This field is used to record the number of items shipped,
+    even if the actual stock items get deleted from the database.
+
+    For existing orders in the database, we calculate this as follows:
+
+    - If the order is "shipped" then we use the total quantity
+    - Otherwise, we use the "fulfilled" calculated quantity
+
+    """
+
+    StockItem = apps.get_model('stock', 'stockitem')
+    SalesOrderLineItem = apps.get_model('order', 'salesorderlineitem')
+
+    for item in SalesOrderLineItem.objects.all():
+
+        if item.order.status == SalesOrderStatus.SHIPPED:
+            item.shipped = item.quantity
+        else:
+            # Calculate total stock quantity of items allocated to this order?
+            items = StockItem.objects.filter(
+                sales_order=item.order,
+                part=item.part
+            )
+
+            q = sum([item.quantity for item in items])
+
+            item.shipped = q
+
+        item.save()
+
+
+def reverse_calculate_shipped_quantity(apps, schema_editor):
+    """
+    Provided only for reverse migration compatibility.
+    This function does nothing.
+    """
+    pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('order', '0057_salesorderlineitem_shipped'),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            calculate_shipped_quantity,
+            reverse_code=reverse_calculate_shipped_quantity
+        )
+    ]

InvenTree/order/models.py

@@ -814,6 +814,7 @@ class SalesOrderLineItem(OrderLineItem):
         order: Link to the SalesOrder that this line item belongs to
         part: Link to a Part object (may be null)
         sale_price: The unit sale price for this OrderLineItem
+        shipped: The number of items which have actually shipped against this line item
     """
 
     @staticmethod
@@ -838,6 +839,14 @@ class SalesOrderLineItem(OrderLineItem):
         help_text=_('Unit sale price'),
     )
 
+    shipped = RoundingDecimalField(
+        verbose_name=_('Shipped'),
+        help_text=_('Shipped quantity'),
+        default=0,
+        max_digits=15, decimal_places=5,
+        validators=[MinValueValidator(0)]
+    )
+
     class Meta:
         unique_together = [
         ]

InvenTree/order/serializers.py

@@ -555,6 +555,8 @@ class SOLineItemSerializer(InvenTreeModelSerializer):
     allocated = serializers.FloatField(source='allocated_quantity', read_only=True)
     fulfilled = serializers.FloatField(source='fulfilled_quantity', read_only=True)
 
+    shipped = InvenTreeDecimalField(read_only=True)
+
     sale_price = InvenTreeMoneySerializer(
         allow_null=True
     )
@@ -584,6 +586,7 @@ class SOLineItemSerializer(InvenTreeModelSerializer):
             'sale_price',
             'sale_price_currency',
             'sale_price_string',
+            'shipped',
         ]