Base model, manager, field, form and admin classes for Edc.

All models in the Edc use BaseUuidModel

from edc_model.model_mixins import BaseUuidModel

class MyModel(BaseUuidModel):

    ....

The mixin:

• sets the id fields to a UUIDField instead of an integer;
• adds audit fields through BaseModel (user_created, user_modified, date_created, etc);
• adds UrlModelMixin, DeviceModelMixin

Most models require an audit trail. If so, add the HistoricalRecord model manager.

from edc_model.model.models import HistoricalRecord

class MyModel(BaseUuidModel):

    ...
    history = HistoricalRecord()

HistoricalRecord is an almost identical version of simple_history.models.HistoricalRecord with the exception of two methods: get_extra_fields() and add_extra_methods(). Method get_extra_fields() is overridden to change the history_id primary key from an IntegerField to a UUIDField so that it can work with module django_collect_offline.

The audit trail models created by HistoricalRecord have a foreign key to auth.User. In order for the models to work with django_collect_offline specify the django_collect_offline User model in settings:

AUTH_USER_MODEL = 'django_collect_offline.User'

User created and modified fields behave as follows:

• created is only set on pre-save add
• modified is always updated