add customer field to credit notes for when they are not related to a user directly

src/shop/migrations/0050_auto_20170916_1336.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-09-16 11:36
+from __future__ import unicode_literals
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('shop', '0049_auto_20170914_2034'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='creditnote',
+            name='customer',
+            field=models.TextField(blank=True, default='', help_text='Customer info if no user is selected'),
+        ),
+        migrations.AlterField(
+            model_name='creditnote',
+            name='text',
+            field=models.TextField(help_text='Description of what this credit note covers'),
+        ),
+        migrations.AlterField(
+            model_name='creditnote',
+            name='user',
+            field=models.ForeignKey(blank=True, help_text='The user this credit note belongs to, if any.', null=True, on_delete=django.db.models.deletion.CASCADE, related_name='creditnotes', to=settings.AUTH_USER_MODEL, verbose_name='User'),
+        ),
+    ]

src/shop/models.py

@@ -380,33 +380,70 @@ class CreditNote(CreatedUpdatedModel):
     class Meta:
         ordering = ['-created']
 
-    amount = models.DecimalField(max_digits=10, decimal_places=2)
-    text = models.TextField()
+    amount = models.DecimalField(
+        max_digits=10,
+        decimal_places=2
+    )
+
+    text = models.TextField(
+        help_text="Description of what this credit note covers"
+    )
+
     pdf = models.FileField(
         null=True,
         blank=True,
         upload_to='creditnotes/'
     )
+
     user = models.ForeignKey(
         'auth.User',
         verbose_name=_('User'),
-        help_text=_('The user this credit note belongs to.'),
+        help_text=_('The user this credit note belongs to, if any.'),
         related_name='creditnotes',
+        null=True,
+        blank=True
     )
+
+    customer = models.TextField(
+        help_text="Customer info if no user is selected",
+        blank=True,
+        default='',
+    )
+
     paid = models.BooleanField(
         verbose_name=_('Paid?'),
         help_text=_('Whether the amount in this creditnote has been paid back to the customer.'),
         default=False,
     )
+
     sent_to_customer = models.BooleanField(default=False)
 
+    def clean(self):
+        errors = []
+        if self.user and self.customer:
+            msg = "Customer info should be blank if a user is selected."
+            errors.append(ValidationError({'user', msg}))
+            errors.append(ValidationError({'customer', msg}))
+        if not self.user and not self.customer:
+            msg = "Either pick a user or fill in Customer info"
+            errors.append(ValidationError({'user', msg}))
+            errors.append(ValidationError({'customer', msg}))
+        if errors:
+            raise ValidationError(errors)
+
     def __str__(self):
-        return 'creditnote#%s - %s DKK (sent to %s: %s)' % (
-            self.id,
-            self.amount,
-            self.user.email,
-            self.sent_to_customer,
-        )
+        if self.user:
+            return 'creditnoote#%s - %s DKK (customer: user %s)' % (
+                self.id,
+                self.amount,
+                self.user.email,
+            )
+        else:
+            return 'creditnoote#%s - %s DKK (customer: user %s)' % (
+                self.id,
+                self.amount,
+                self.customer,
+            )
 
     @property
     def vat(self):

src/shop/templates/pdf/creditnote.html

@@ -13,7 +13,7 @@
         </td>
     </tr>
 </table>
-<h3>Customer: {{ creditnote.user.email }}</h3>
+<h3>Customer: {% if creditnote.user %}{{ creditnote.user.email }}{% else %}{{ creditnote.customer }}{% endif %}</h3>
 <br>
 <h2>CREDITNOTE</h2>
 <table style="width:90%; margin:1em;">