Add "is_building" field to StockItem model

- This will be set to TRUE until a stock item has been completed

InvenTree/stock/migrations/0052_stockitem_is_building.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.7 on 2020-10-04 13:12
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0051_auto_20200928_0928'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitem',
+            name='is_building',
+            field=models.BooleanField(default=False),
+        ),
+    ]

InvenTree/stock/models.py

@@ -130,6 +130,7 @@ class StockItem(MPTTModel):
         status: Status of this StockItem (ref: InvenTree.status_codes.StockStatus)
         notes: Extra notes field
         build: Link to a Build (if this stock item was created from a build)
+        is_building: Boolean field indicating if this stock item is currently being built
         purchase_order: Link to a PurchaseOrder (if this stock item was created from a PurchaseOrder)
         infinite: If True this StockItem can never be exhausted
         sales_order: Link to a SalesOrder object (if the StockItem has been assigned to a SalesOrder)
@@ -389,6 +390,10 @@ class StockItem(MPTTModel):
         related_name='build_outputs',
     )
 
+    is_building = models.BooleanField(
+        default=False,
+    )
+
     purchase_order = models.ForeignKey(
         'order.PurchaseOrder',
         on_delete=models.SET_NULL,