fields.rst

.. automodule:: boogie.fields

Fields

Django Boogie defines a few fields for your convenience.

EnumField

Django support for enumerations is based on the choices argument of integer or text-based fields. Now that Python 3 supports Enum types, this approach is sub-optimal and also involves lots of undesirable boilerplate.

from django.db import models

class User(models.Model):
    ROLE_TEACHER = 0
    ROLE_STUDENT = 1
    ROLE_CHOICES = [
        (ROLE_TEACHER, 'teacher'),
        (ROLE_STUDENT, 'student'),
    ]
    name = models.CharField(max_length=140)
    role = models.IntegerField(choices=ROLE_CHOICES)

    def can_create_classrooms(self):
        """
        Only teachers can create classrooms.
        """
        return self.role == self.ROLE_TEACHER

Now we can define a RoleEnum and use a EnumField in order to simplify things.

from boogie import models
from boogie.fields import DescriptionEnum


class RoleEnum(DescriptionEnum):
    TEACHER = 0, 'teacher'
    STUDENT = 1, 'student'

class User(models.Model):
    name = models.CharField(max_length=140)
    role = models.EnumField(RoleEnum)

    def can_create_classrooms(self):
        """
        Only teachers can create classrooms.
        """
        return self.role == self.ROLE_TEACHER

The EnumField accepts standard Python :class:`Enum` and :class:`IntEnum` classes. Boogie defines the corresponding :class:`Enum` :class:`IntEnum` that provides human-friendly names for each enumeration and thus integrates more nicely with Django and gettext.

A model that declares a :class:`EnumField` is automatically filled with all possible ROLE_* attributes for each value in the enumeration. :class:`EnumField`s automatically computes the 'choices' argument, and users cannot override it.

API Documentation

.. autoclass:: EnumField
    :members:

.. autoclass:: Enum
    :members:

.. autoclass:: IntEnum
    :members: