Add a checksum field to the bom line item

InvenTree/part/migrations/0017_bomitem_checksum.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.4 on 2019-09-05 02:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0016_auto_20190820_0257'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='bomitem',
+            name='checksum',
+            field=models.CharField(blank=True, help_text='BOM line checksum', max_length=128),
+        ),
+    ]

InvenTree/part/models.py

@@ -1121,6 +1121,7 @@ class BomItem(models.Model):
         reference: BOM reference field (e.g. part designators)
         overage: Estimated losses for a Build. Can be expressed as absolute value (e.g. '7') or a percentage (e.g. '2%')
         note: Note field for this BOM item
+        checksum: Validation checksum for the particular BOM line item
     """
 
     def get_absolute_url(self):
@@ -1154,6 +1155,8 @@ class BomItem(models.Model):
     # Note attached to this BOM line item
     note = models.CharField(max_length=500, blank=True, help_text='BOM item notes')
 
+    checksum = models.CharField(max_length=128, blank=True, help_text='BOM line checksum')
+
     def clean(self):
         """ Check validity of the BomItem model.