edc-registration

The model RegisteredSubject is used by the Edc as the master subject registration table. Only one record may exist per individual. The table has space for PII so typically a RegisteredSubject instance is created or updated on completion of the informed consent. As always, PII in the Edc is encrypted at rest using django-crypto-field.

For the model and signal to be registered you need to add the AppConfig to your INSTALLED_APPS:

INSTALLED_APPS = (
    ....
    'edc_registration.apps.AppConfig',
    ....
)

UpdatesOrCreatesRegistrationModelMixin

RegisteredSubject is never edited directly by the user. Instead some other model with the needed attributes is used as a proxy. To have a model perform the task of creating or updating RegisteredSubject, declare it with the UpdatesOrCreatesRegistrationModelMixin.

For example, a model, SubjectEligibility or a screening model creates or updates RegisteredSubject without a subject identifier then a model such as the SubjectConsent in tests.models, also creates or updates a subject's RegisteredSubject instance on save. For this to happen, both models are declared with the UpdatesOrCreatesRegistrationModelMixin:

class SubjectEligibility(UniqueSubjectIdentifierModelMixin,
                         UpdatesOrCreatesRegistrationModelMixin, BaseUuidModel):

    screening_identifier = models.CharField(
        max_length=36,
        null=True,
        unique=True)

    @property
    def registration_unique_field(self):
        return 'screening_identifier'

    def update_subject_identifier_on_save(self):
        """Overridden to not set the subject identifier on save.
        """
        if not self.subject_identifier:
            self.subject_identifier = self.subject_identifier_as_pk.hex
            self.subject_identifier_aka = self.subject_identifier_as_pk.hex
        return self.subject_identifier

class SubjectConsent(
    ConsentModelMixin, UpdatesOrCreatesRegistrationModelMixin,
    CreateAppointmentsMixin, IdentityFieldsMixin, ReviewFieldsMixin,
    PersonalFieldsMixin, CitizenFieldsMixin, VulnerabilityFieldsMixin,
    BaseUuidModel):

            @property
        def registration_unique_field(self):
            return 'screening_identifier'

        class Meta:
            app_label = 'my_app'

The property registration_unique_field returns a model attribute that is used to set a registration identifier on RegisteredSubject.

A subject's RegisteredSubject instance is created and updated in a post_save signal. As mentioned, it is never edited directly by the user.