diff options
| -rw-r--r-- | rest_framework/fields.py | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/rest_framework/fields.py b/rest_framework/fields.py index 8b495d6e..5b406703 100644 --- a/rest_framework/fields.py +++ b/rest_framework/fields.py @@ -7,7 +7,6 @@ from django.core import validators from django.core.exceptions import ValidationError from django.conf import settings from django.db import DEFAULT_DB_ALIAS -from django.db.models.related import RelatedObject from django.utils.encoding import is_protected_type, smart_unicode from django.utils.translation import ugettext_lazy as _ from rest_framework.compat import parse_date, parse_datetime @@ -199,27 +198,23 @@ class RelatedField(Field): class PrimaryKeyRelatedField(RelatedField): """ - Serializes a model related field or related manager to a pk value. + Serializes a related field or related object to a pk value. """ - # Note the we use ModelRelatedField's implementation, as we want to get the - # raw database value directly, since that won't involve another - # database lookup. - # - # An alternative implementation would simply be this... - # - # class PrimaryKeyRelatedField(RelatedField): - # def to_native(self, obj): - # return obj.pk def to_native(self, pk): """ - Simply returns the object's pk. You can subclass this method to - provide different serialization behavior of the pk. - (For example returning a URL based on the model's pk.) + You can subclass this method to provide different serialization + behavior based on the pk. """ return pk def field_to_native(self, obj, field_name): + # This is only implemented for performance reasons + # + # We could leave the default `RelatedField.field_to_native()` in place, + # and inside just implement `to_native()` as `return obj.pk` + # + # That would involve an extra database lookup. try: pk = obj.serializable_value(self.source or field_name) except AttributeError: @@ -235,6 +230,10 @@ class PrimaryKeyRelatedField(RelatedField): class ManyPrimaryKeyRelatedField(PrimaryKeyRelatedField): + """ + Serializes a to-many related field or related manager to a pk value. + """ + def field_to_native(self, obj, field_name): try: queryset = obj.serializable_value(self.source or field_name) |