Created a Sender model

src/documents/migrations/0003_sender.py

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9 on 2016-01-11 12:21
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.template.defaultfilters import slugify
+
+import django.db.models.deletion
+
+
+DOCUMENT_SENDER_MAP = {}
+
+
+def move_sender_strings_to_sender_model(apps, schema_editor):
+
+    sender_model = apps.get_model("documents", "Sender")
+    document_model = apps.get_model("documents", "Document")
+
+    # Create the sender and log the relationship with the document
+    for document in document_model.objects.all():
+        if document.sender:
+            DOCUMENT_SENDER_MAP[document.pk], created = sender_model.objects.get_or_create(
+                name=document.sender,
+                defaults={"slug": slugify(document.sender)}
+            )
+
+
+def realign_senders(apps, schema_editor):
+    document_model = apps.get_model("documents", "Document")
+    for pk, sender in DOCUMENT_SENDER_MAP.items():
+        document_model.objects.filter(pk=pk).update(sender=sender)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '0002_auto_20151226_1316'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Sender',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=128, unique=True)),
+                ('slug', models.SlugField()),
+            ],
+        ),
+        migrations.RunPython(move_sender_strings_to_sender_model),
+        migrations.AlterField(
+            model_name='document',
+            name='sender',
+            field=models.ForeignKey(blank=True, on_delete=django.db.models.deletion.CASCADE, to='documents.Sender'),
+        ),
+        migrations.RunPython(realign_senders),
+    ]