LamsonProject: Hooking Lamson Into Django

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# Hooking Lamson Into Django

This is a short document because using Django ORM is very simple from Lamson. The trick is to fake out Django so that when you import the Django model into Lamson, the Django model knows where it’s living and will operate. We’ll go through an “integration” step by step.

# Step 1: Make Your Django App Work

There’s no point in trying to import an ORM that doesn’t work. So get it working, maybe write some tests.

An important thing is that you should be able to run `python manage.py shell` and import your model without problems.

## Step 2: Fake Out Django

You then have to put an environment variable in your Lamson `config/settings.py` file before you load any Django Models:

    os.environ['DJANGO_SETTINGS_MODULE'] = 'webapp.settings'

This is from the librelist.com examples, where the Django models are in `webapp` so we our settings module from Lamson perspective is `webapp.settings`.

## Step 3: Use The Django Models

After that, you can just import your models however you want. Here’s an example of Librelist using a Django Model to store confirmations:

    from webapp.librelist.models import Confirmation

    class DjangoConfirmStorage():
        def clear(self):
            Confirmation.objects.all().delete()

        def get(self, target, from_address):
            confirmations = Confirmation.objects.filter(from_address=from_address,
                                                    list_name=target)
            if confirmations:
                return confirmations[0].expected_secret, confirmations[0].pending_message_id
            else:
                return None, None

        def delete(self, target, from_address):
            Confirmation.objects.filter(from_address=from_address,
                                                    list_name=target).delete()

        def store(self, target, from_address, expected_secret, pending_message_id):
            conf = Confirmation(from_address=from_address,
                                expected_secret = expected_secret,
                                pending_message_id = pending_message_id,
                                list_name=target)
            conf.save()

## Well, That Wasn’t Too Hard

The only thing you’ll have to contend with is where code you need to use these models lives. Since it’s all Python, you can just import what you need, but my recommendation is to focus most of your model code into your Django application, and then only put a small amount into Lamson.

For more information, look in the Lamson source releases to see how Django is used in the `examples/librelist` code.