Add "install_into" field for BuildItem

- Points to which output stock item it will be going into

InvenTree/build/migrations/0021_auto_20201020_0908.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.0.7 on 2020-10-20 09:08
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0052_stockitem_is_building'),
+        ('build', '0020_auto_20201019_1325'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='builditem',
+            name='install_into',
+            field=models.ForeignKey(blank=True, help_text='Destination stock item', limit_choices_to={'is_building': True}, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='items_to_install', to='stock.StockItem'),
+        ),
+        migrations.AlterField(
+            model_name='builditem',
+            name='stock_item',
+            field=models.ForeignKey(help_text='Source stock item', limit_choices_to={'belongs_to': None, 'build_order': None, 'sales_order': None}, on_delete=django.db.models.deletion.CASCADE, related_name='allocations', to='stock.StockItem'),
+        ),
+    ]

InvenTree/build/models.py

@@ -568,7 +568,7 @@ class BuildItem(models.Model):
         'stock.StockItem',
         on_delete=models.CASCADE,
         related_name='allocations',
-        help_text=_('Stock Item to allocate to build'),
+        help_text=_('Source stock item'),
         limit_choices_to={
             'build_order': None,
             'sales_order': None,
@@ -583,3 +583,14 @@ class BuildItem(models.Model):
         validators=[MinValueValidator(0)],
         help_text=_('Stock quantity to allocate to build')
     )
+
+    install_into = models.ForeignKey(
+        'stock.StockItem',
+        on_delete=models.SET_NULL,
+        blank=True, null=True,
+        related_name='items_to_install',
+        help_text=_('Destination stock item'),
+        limit_choices_to={
+            'is_building': True,
+        }
+    )

InvenTree/stock/api.py

@@ -493,6 +493,12 @@ class StockList(generics.ListCreateAPIView):
         if build_order:
             queryset = queryset.filter(build_order=build_order)
 
+        is_building = params.get('is_building', None)
+
+        if is_building:
+            is_building = str2bool(is_building)
+            queryset = queryset.filter(is_building=is_building)
+
         sales_order = params.get('sales_order', None)
 
         if sales_order: