Django Rest framework, how to include '__all__' fields and a related field in ModelSerializer ?
Like @DanEEStart said, DjangoRestFramework don't have a simple way to extend the 'all' value for fields, because the get_field_names
methods seems to be designed to work that way.
But fortunately you can override this method to allow a simple way to include all fields and relations without enumerate a tons of fields.
I override this method like this:
class ToppingSerializer(serializers.ModelSerializer):
class Meta:
model = Topping
fields = '__all__'
extra_fields = ['pizzas']
def get_field_names(self, declared_fields, info):
expanded_fields = super(ToppingSerializer, self).get_field_names(declared_fields, info)
if getattr(self.Meta, 'extra_fields', None):
return expanded_fields + self.Meta.extra_fields
else:
return expanded_fields
Note that this method only change the behaviour of this serializer, and the extra_fields
attribute only works on this serializer class.
If you have a tons of serializer like this, you can create a intermediate class to include this get_fields_names
method in one place and reuse'em many times. Some like this:
class CustomSerializer(serializers.HyperlinkedModelSerializer):
def get_field_names(self, declared_fields, info):
expanded_fields = super(CustomSerializer, self).get_field_names(declared_fields, info)
if getattr(self.Meta, 'extra_fields', None):
return expanded_fields + self.Meta.extra_fields
else:
return expanded_fields
class ToppingSerializer(CustomSerializer):
class Meta:
model = Topping
fields = '__all__'
extra_fields = ['pizzas']
class AnotherSerializer(CustomSerializer):
class Meta:
model = Post
fields = '__all__'
extra_fields = ['comments']
I just checked the source code of Django Rest Framework. The behaviour you want seems not to be supported in the Framework.
The fields
option must be a list, a tuple or the text __all__
.
Here is a snippet of the relevant source code:
ALL_FIELDS = '__all__'
if fields and fields != ALL_FIELDS and not isinstance(fields, (list, tuple)):
raise TypeError(
'The `fields` option must be a list or tuple or "__all__". '
'Got %s.' % type(fields).__name__
)
You cannot add 'all' additionally to the tuple or list with fields...
The fields="__all__"
option can work by specifying an additional field manually as per the following examples. This is by far the cleanest solution around for this issue.
Nested Relationships
http://www.django-rest-framework.org/api-guide/relations/#nested-relationships
class TrackSerializer(serializers.ModelSerializer):
class Meta:
model = Track
fields = '__all__'
class AlbumSerializer(serializers.ModelSerializer):
tracks = TrackSerializer(many=True, read_only=True)
class Meta:
model = Album
fields = '__all__'
I would assume this would work for any of the other related field options listed on the same page: http://www.django-rest-framework.org/api-guide/relations/#serializer-relations
Reverse relation example
class TrackSerializer(serializers.ModelSerializer):
album = AlbumSerializer(source='album_id')
class Meta:
model = Track
fields = '__all__'
Note: Created using Django Rest Framework version 3.6.2, subject to change. Please add a comment if any future changes break any examples posted above.