Require Build and StockItem to be unique_together in BuildItem class

InvenTree/build/migrations/0007_auto_20190429_2255.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2 on 2019-04-29 12:55
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0009_auto_20190428_0841'),
+        ('build', '0006_auto_20190429_2233'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='builditem',
+            unique_together={('build', 'stock_item')},
+        ),
+    ]

InvenTree/build/models.py

@@ -6,6 +6,7 @@ Build database model definitions
 from __future__ import unicode_literals
 
 from django.utils.translation import ugettext as _
+from django.core.exceptions import ValidationError
 
 from django.urls import reverse
 from django.db import models
@@ -128,6 +129,26 @@ class BuildItem(models.Model):
         quantity: Number of units allocated
     """
 
+    class Meta:
+        unique_together = [
+            ('build', 'stock_item'),
+        ]
+
+    def clean(self):
+        """ Check validity of the BuildItem model.
+        The following checks are performed:
+
+        - StockItem.part must be in the BOM of the Part object referenced by Build
+        """
+
+        if self.stock_item.part not in self.build.part.required_parts():
+            print('stock_item:', self.stock_item.part)
+            for p in self.build.part.bom_items.all():
+                print('bom_part:', p)
+            raise ValidationError(
+                {'stock_item': _("Selected stock item not found in BOM for part '{p}'".format(p=str(self.build.part)))}
+            )
+
     build = models.ForeignKey(
         Build,
         on_delete=models.CASCADE,

InvenTree/build/serializers.py

@@ -6,11 +6,11 @@ JSON serializers for Build API
 from __future__ import unicode_literals
 
 from rest_framework import serializers
+from InvenTree.serializers import InvenTreeModelSerializer
 
-from .models import Build
+from .models import Build, BuildItem
 
-
+class BuildSerializer(InvenTreeModelSerializer):
-class BuildSerializer(serializers.ModelSerializer):
     """ Serializes a Build object """
 
     url = serializers.CharField(source='get_absolute_url', read_only=True)
@@ -29,3 +29,15 @@ class BuildSerializer(serializers.ModelSerializer):
             'status',
             'status_text',
             'notes']
+
+
+class BuildItemSerializer(InvenTreeModelSerializer):
+    """ Serializes a BuildItem object """
+
+    class Meta:
+        model = BuildItem
+        fields = [
+            'build',
+            'stock',
+            'quantity'
+        ]