Add 'batch' field to BuildOutput object

This 'batch' output will be copied to any parts produced as part of this build

InvenTree/build/admin.py

@@ -3,7 +3,7 @@ from __future__ import unicode_literals
 
 from django.contrib import admin
 
-from .models import Build
+from .models import Build, BuildOutput
 
 
 class BuildAdmin(admin.ModelAdmin):
@@ -11,4 +11,10 @@ class BuildAdmin(admin.ModelAdmin):
     list_display = ('status', )
 
 
+class BuildOutputAdmin(admin.ModelAdmin):
+
+    list_display = ('build', 'part', 'batch', 'quantity', )
+
+
 admin.site.register(Build, BuildAdmin)
+admin.site.register(BuildOutput, BuildOutputAdmin)

InvenTree/build/migrations/0005_buildoutput_batch.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.12 on 2018-04-17 08:29
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('build', '0004_auto_20180417_0657'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='buildoutput',
+            name='batch',
+            field=models.CharField(blank=True, help_text='Batch code for this build output', max_length=100),
+        ),
+    ]

InvenTree/build/models.py

@@ -40,12 +40,19 @@ class BuildOutput(models.Model):
     A build output represents a single build part/quantity combination
     """
 
+    batch = models.CharField(max_length=100, blank=True,
+                             help_text='Batch code for this build output')
+
+    # Reference to the build object of which this output is a part
+    # A build can have multiple outputs
     build = models.ForeignKey(Build, on_delete=models.CASCADE,
                               related_name='outputs')
 
+    # A reference to the part being built
     part = models.ForeignKey(Part, on_delete=models.CASCADE,
                              related_name='builds')
 
+    # How many parts to build?
     quantity = models.PositiveIntegerField(default=1,
                                            validators=[MinValueValidator(1)],
                                            help_text='Number of parts to build')