Loading initial data with Django 1.7 and data migrations

Question

I recently switched from Django 1.6 to 1.7, and I began using migrations (I never used South).

Before 1.7, I used to load initial data with a fixture/initial_d

Answer 1

Update: See @GwynBleidD's comment below for the problems this solution can cause, and see @Rockallite's answer below for an approach that's more durable to future model changes.

---

Assuming you have a fixture file in /fixtures/initial_data.json

1. Create your empty migration:

   In Django 1.7:

   python manage.py makemigrations --empty 
   

   In Django 1.8+, you can provide a name:

   python manage.py makemigrations --empty  --name load_intial_data
   

2. Edit your migration file /migrations/0002_auto_xxx.py

   2.1. Custom implementation, inspired by Django' loaddata (initial answer):

   import os
   from sys import path
   from django.core import serializers
   
   fixture_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '../fixtures'))
   fixture_filename = 'initial_data.json'
   
   def load_fixture(apps, schema_editor):
       fixture_file = os.path.join(fixture_dir, fixture_filename)
   
       fixture = open(fixture_file, 'rb')
       objects = serializers.deserialize('json', fixture, ignorenonexistent=True)
       for obj in objects:
           obj.save()
       fixture.close()
   
   def unload_fixture(apps, schema_editor):
       "Brutally deleting all entries for this model..."
   
       MyModel = apps.get_model("yourapp", "ModelName")
       MyModel.objects.all().delete()
   
   class Migration(migrations.Migration):  
   
       dependencies = [
           ('yourapp', '0001_initial'),
       ]
   
       operations = [
           migrations.RunPython(load_fixture, reverse_code=unload_fixture),
       ]
   

   2.2. A simpler solution for load_fixture (per @juliocesar's suggestion):

   from django.core.management import call_command
   
   fixture_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '../fixtures'))
   fixture_filename = 'initial_data.json'
   
   def load_fixture(apps, schema_editor):
       fixture_file = os.path.join(fixture_dir, fixture_filename)
       call_command('loaddata', fixture_file) 
   

   Useful if you want to use a custom directory.

   2.3. Simplest: calling loaddata with app_label will load fixtures from the 's fixtures dir automatically :

   from django.core.management import call_command
   
   fixture = 'initial_data'
   
   def load_fixture(apps, schema_editor):
       call_command('loaddata', fixture, app_label='yourapp') 
   

   If you don't specify app_label, loaddata will try to load fixture filename from all apps fixtures directories (which you probably don't want).

3. Run it

   python manage.py migrate