Change foreign keys to TreeForeignKey

InvenTree/stock/migrations/0013_auto_20190908_0916.py

@@ -0,0 +1,20 @@
+# Generated by Django 2.2.5 on 2019-09-08 09:16
+
+from django.db import migrations
+import django.db.models.deletion
+import mptt.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0012_auto_20190908_0405'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='stockitem',
+            name='location',
+            field=mptt.fields.TreeForeignKey(blank=True, help_text='Where is this stock item located?', null=True, on_delete=django.db.models.deletion.DO_NOTHING, related_name='stock_items', to='stock.StockLocation'),
+        ),
+    ]

InvenTree/stock/migrations/0014_auto_20190908_0918.py

@@ -0,0 +1,20 @@
+# Generated by Django 2.2.5 on 2019-09-08 09:18
+
+from django.db import migrations
+import django.db.models.deletion
+import mptt.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0013_auto_20190908_0916'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='stocklocation',
+            name='parent',
+            field=mptt.fields.TreeForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.DO_NOTHING, related_name='children', to='stock.StockLocation'),
+        ),
+    ]

InvenTree/stock/models.py

@@ -16,6 +16,8 @@ from django.contrib.auth.models import User
 from django.db.models.signals import pre_delete
 from django.dispatch import receiver
 
+from mptt.models import TreeForeignKey
+
 from datetime import datetime
 from InvenTree import helpers
 
@@ -292,9 +294,9 @@ class StockItem(models.Model):
     supplier_part = models.ForeignKey('company.SupplierPart', blank=True, null=True, on_delete=models.SET_NULL,
                                       help_text='Select a matching supplier part for this stock item')
 
-    location = models.ForeignKey(StockLocation, on_delete=models.DO_NOTHING,
-                                 related_name='stock_items', blank=True, null=True,
-                                 help_text='Where is this stock item located?')
+    location = TreeForeignKey(StockLocation, on_delete=models.DO_NOTHING,
+                              related_name='stock_items', blank=True, null=True,
+                              help_text='Where is this stock item located?')
 
     belongs_to = models.ForeignKey('self', on_delete=models.DO_NOTHING,
                                    related_name='owned_parts', blank=True, null=True,