"""

Tests for defer() and only().

"""

from django.db import models

class Secondary(models.Model):

    first = models.CharField(max_length=50)

    second = models.CharField(max_length=50)

class Primary(models.Model):

    name = models.CharField(max_length=50)

    value = models.CharField(max_length=50)

    related = models.ForeignKey(Secondary, models.CASCADE)

    def __str__(self):

        return self.name

class Child(Primary):

    pass

class BigChild(Primary):

    other = models.CharField(max_length=50)

class ChildProxy(Child):

    class Meta:

        proxy = True

class RefreshPrimaryProxy(Primary):

    class Meta:

        proxy = True

    def refresh_from_db(self, using=None, fields=None, **kwargs):

        # Reloads all deferred fields if any of the fields is deferred.

        if fields is not None:

            fields = set(fields)

            deferred_fields = self.get_deferred_fields()

            if fields.intersection(deferred_fields):

                fields = fields.union(deferred_fields)

        super().refresh_from_db(using, fields, **kwargs)

class ShadowParent(models.Model):

    """

    ShadowParent declares a scalar, rather than a field. When this is

    overridden, the field value, rather than the scalar value must still be

    used when the field is deferred.

    """

    name = "aphrodite"

class ShadowChild(ShadowParent):

    name = models.CharField(default="adonis", max_length=6)