Lazy Manager Insertion

Warning

This is just a stub document. It will be fleshed out more. If you wish to comment on it, please e-mail coreyoordt at gmail.

Loosely based on Django-mptt. It is very similar to how we handled inserting a field.

COOLAPP_MODELS = {
    'app1.Model': 'cool_manager',
    'app2.Model': 'cool_manager',
}

At the bottom of this app’s models.py, you can read the configuration from settings.

loop through them and Do a bit of error checking

Load the model class

Loop through the given fields

We make sure that the model doesn’t have an attribute by the same name, we add the field to the model by instantiating the manager and calling its contribute_to_class method.

from django.db.models import get_model
import django.conf import settings
from coolapp.managers import CustomManager

MODELS = getattr(settings, 'COOLAPP_MODELS', {})

for model_name, mgr_name in MODELS.items():
    if not isinstance(model_name, basestring):
        continue

    model = get_model(*model_name.split('.'))

    if not getattr(model, mgr_name, False):
        manager = CustomManager()
        manager.contribute_to_class(model, mgr_name)