edc-visit-tracking 0.2.12

Base classes for visit reports/tracking in clinicedc/edc.

[](https://travis-ci.org/clinicedc/edc-visit-tracking) [](https://coveralls.io/github/clinicedc/edc-visit-tracking?branch=develop)

# edc-visit-tracking

Track study participant visit reports.


### Declaring a visit model

A __visit_model__ is declared using the model mixin `VisitModelMixin`. Normally, a __visit_model__ will be declared with additional model mixins, but `VisitModelMixin` must be there.

class SubjectVisit(VisitModelMixin, BaseUuidModel):
...

Also, ensure the `Meta` class attributes of `VisitModelMixin` are inherited. These include required constraints and ordering.

class SubjectVisit(VisitModelMixin, BaseUuidModel):

...

class Meta(VisitModelMixin.Meta):
pass

Among other features, `VisitModelMixin` adds a `OneToOneField` foreign key to the __visit_model__ that points to `edc_appointment.Appointment`.

> Important: A __visit model__ is a special model in the EDC. A model declared with the model mixin, `VisitModelMixin`, is the definition of a __visit model__. CRFs and Requisitions have a foreign key pointing to a __visit model__. A number of methods on CRFs and Requisitions detect their __visit model__ foreign key name, model class and value by looking for the FK declared with `VisitModelMixin`.


For a subject that requires ICF the __visit model__ would look like this:

class SubjectVisit(VisitModelMixin, OffstudyMixin, CreatesMetadataModelMixin, RequiresConsentModelMixin, BaseUuidModel):

class Meta(VisitModelMixin.Meta):
consent_model = 'myapp.subjectconsent' # for RequiresConsentModelMixin


If the subject does not require ICF, such as an infant, don't include the `RequiresConsentModelMixin`:

class InfantVisit(VisitModelMixin, OffstudyMixin, CreatesMetadataModelMixin, BaseUuidModel):

class Meta(VisitModelMixin.Meta):
pass

### Declaring a CRF

The `CrfModelMixin` is required for all CRF models. CRF models have a `OneToOneField` key to a __visit model__.

class CrfOne(CrfModelMixin, OffstudyCrfModelMixin, RequiresConsentModelMixin, UpdatesCrfMetadataModelMixin, BaseUuidModel):

subject_visit = models.OneToOneField(SubjectVisit)

f1 = models.CharField(max_length=10, default='erik')

vl = models.CharField(max_length=10, default=NO)

rdb = models.CharField(max_length=10, default=NO)

class Meta:
consent_model = 'myapp.subjectconsent' # for RequiresConsentModelMixin

### Declaring forms:

The `VisitFormMixin` includes a number of common validations in the `clean` method:

class SubjectVisitForm(VisitFormMixin, forms.ModelForm):

class Meta:
model = SubjectVisit

### `PreviousVisitModelMixin`

The `PreviousVisitModelMixin` ensures that visits are entered in sequence. It is included with the `VisitModelMixin`.