django-rest-framework/rest_framework/serializers.py

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"""
Serializers and ModelSerializers are similar to Forms and ModelForms.
Unlike forms, they are not constrained to dealing with HTML output, and
form encoded input.
Serialization in REST framework is a two-phase process:
1. Serializers marshal between complex types like model instances, and
python primitives.
2. The process of marshalling between python primitives and request and
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response content is handled by parsers and renderers.
"""
from django.core.exceptions import ImproperlyConfigured
from django.db import models
from django.db.models.fields import FieldDoesNotExist
from django.utils import six
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from django.utils.datastructures import SortedDict
from django.utils.translation import ugettext_lazy as _
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from rest_framework.exceptions import ValidationError
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from rest_framework.fields import empty, set_value, Field, SkipField
from rest_framework.settings import api_settings
from rest_framework.utils import html, model_meta, representation
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from rest_framework.utils.field_mapping import (
get_url_kwargs, get_field_kwargs,
get_relation_kwargs, get_nested_relation_kwargs,
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ClassLookupDict
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)
from rest_framework.validators import (
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UniqueForDateValidator, UniqueForMonthValidator, UniqueForYearValidator,
UniqueTogetherValidator
)
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import copy
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import inspect
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import warnings
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# Note: We do the following so that users of the framework can use this style:
#
# example_field = serializers.CharField(...)
#
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# This helps keep the separation between model fields, form fields, and
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# serializer fields more explicit.
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from rest_framework.relations import * # NOQA
from rest_framework.fields import * # NOQA
# BaseSerializer
# --------------
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class BaseSerializer(Field):
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"""
The BaseSerializer class provides a minimal class which may be used
for writing custom serializer implementations.
"""
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def __init__(self, instance=None, data=None, **kwargs):
self.instance = instance
self._initial_data = data
self.partial = kwargs.pop('partial', False)
self._context = kwargs.pop('context', {})
kwargs.pop('many', None)
super(BaseSerializer, self).__init__(**kwargs)
def __new__(cls, *args, **kwargs):
# We override this method in order to automagically create
# `ListSerializer` classes instead when `many=True` is set.
if kwargs.pop('many', False):
kwargs['child'] = cls()
return ListSerializer(*args, **kwargs)
return super(BaseSerializer, cls).__new__(cls, *args, **kwargs)
def to_internal_value(self, data):
raise NotImplementedError('`to_internal_value()` must be implemented.')
def to_representation(self, instance):
raise NotImplementedError('`to_representation()` must be implemented.')
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def update(self, instance, validated_data):
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raise NotImplementedError('`update()` must be implemented.')
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def create(self, validated_data):
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raise NotImplementedError('`create()` must be implemented.')
def save(self, **kwargs):
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validated_data = self.validated_data
if kwargs:
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validated_data = dict(
list(validated_data.items()) +
list(kwargs.items())
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)
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if self.instance is not None:
self.instance = self.update(self.instance, validated_data)
assert self.instance is not None, (
'`update()` did not return an object instance.'
)
else:
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self.instance = self.create(validated_data)
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assert self.instance is not None, (
'`create()` did not return an object instance.'
)
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return self.instance
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def is_valid(self, raise_exception=False):
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assert not hasattr(self, 'restore_object'), (
'Serializer `%s.%s` has old-style version 2 `.restore_object()` '
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'that is no longer compatible with REST framework 3. '
'Use the new-style `.create()` and `.update()` methods instead.' %
(self.__class__.__module__, self.__class__.__name__)
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)
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if not hasattr(self, '_validated_data'):
try:
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self._validated_data = self.run_validation(self._initial_data)
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except ValidationError as exc:
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self._validated_data = {}
self._errors = exc.detail
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else:
self._errors = {}
if self._errors and raise_exception:
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raise ValidationError(self._errors)
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return not bool(self._errors)
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@property
def data(self):
if not hasattr(self, '_data'):
if self.instance is not None and not getattr(self, '_errors', None):
self._data = self.to_representation(self.instance)
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elif hasattr(self, '_validated_data') and not getattr(self, '_errors', None):
self._data = self.to_representation(self.validated_data)
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else:
self._data = self.get_initial()
return self._data
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@property
def errors(self):
if not hasattr(self, '_errors'):
msg = 'You must call `.is_valid()` before accessing `.errors`.'
raise AssertionError(msg)
return self._errors
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@property
def validated_data(self):
if not hasattr(self, '_validated_data'):
msg = 'You must call `.is_valid()` before accessing `.validated_data`.'
raise AssertionError(msg)
return self._validated_data
# Serializer & ListSerializer classes
# -----------------------------------
class ReturnDict(SortedDict):
"""
Return object from `serialier.data` for the `Serializer` class.
Includes a backlink to the serializer instance for renderers
to use if they need richer field information.
"""
def __init__(self, *args, **kwargs):
self.serializer = kwargs.pop('serializer')
super(ReturnDict, self).__init__(*args, **kwargs)
class ReturnList(list):
"""
Return object from `serialier.data` for the `SerializerList` class.
Includes a backlink to the serializer instance for renderers
to use if they need richer field information.
"""
def __init__(self, *args, **kwargs):
self.serializer = kwargs.pop('serializer')
super(ReturnList, self).__init__(*args, **kwargs)
class BoundField(object):
"""
A field object that also includes `.value` and `.error` properties.
Returned when iterating over a serializer instance,
providing an API similar to Django forms and form fields.
"""
def __init__(self, field, value, errors, prefix=''):
self._field = field
self.value = value
self.errors = errors
self.name = prefix + self.field_name
def __getattr__(self, attr_name):
return getattr(self._field, attr_name)
@property
def _proxy_class(self):
return self._field.__class__
def __repr__(self):
return '<%s value=%s errors=%s>' % (
self.__class__.__name__, self.value, self.errors
)
class NestedBoundField(BoundField):
"""
This BoundField additionally implements __iter__ and __getitem__
in order to support nested bound fields. This class is the type of
BoundField that is used for serializer fields.
"""
def __iter__(self):
for field in self.fields.values():
yield self[field.field_name]
def __getitem__(self, key):
field = self.fields[key]
value = self.value.get(key) if self.value else None
error = self.errors.get(key) if self.errors else None
if isinstance(field, Serializer):
return NestedBoundField(field, value, error, prefix=self.name + '.')
return BoundField(field, value, error, prefix=self.name + '.')
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class BindingDict(object):
"""
This dict-like object is used to store fields on a serializer.
This ensures that whenever fields are added to the serializer we call
`field.bind()` so that the `field_name` and `parent` attributes
can be set correctly.
"""
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def __init__(self, serializer):
self.serializer = serializer
self.fields = SortedDict()
def __setitem__(self, key, field):
self.fields[key] = field
field.bind(field_name=key, parent=self.serializer)
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def __getitem__(self, key):
return self.fields[key]
def __delitem__(self, key):
del self.fields[key]
def items(self):
return self.fields.items()
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def keys(self):
return self.fields.keys()
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def values(self):
return self.fields.values()
class SerializerMetaclass(type):
"""
This metaclass sets a dictionary named `base_fields` on the class.
Any instances of `Field` included as attributes on either the class
or on any of its superclasses will be include in the
`base_fields` dictionary.
"""
@classmethod
def _get_declared_fields(cls, bases, attrs):
fields = [(field_name, attrs.pop(field_name))
for field_name, obj in list(attrs.items())
if isinstance(obj, Field)]
fields.sort(key=lambda x: x[1]._creation_counter)
# If this class is subclassing another Serializer, add that Serializer's
# fields. Note that we loop over the bases in *reverse*. This is necessary
# in order to maintain the correct order of fields.
for base in bases[::-1]:
if hasattr(base, '_declared_fields'):
fields = list(base._declared_fields.items()) + fields
return SortedDict(fields)
def __new__(cls, name, bases, attrs):
attrs['_declared_fields'] = cls._get_declared_fields(bases, attrs)
return super(SerializerMetaclass, cls).__new__(cls, name, bases, attrs)
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@six.add_metaclass(SerializerMetaclass)
class Serializer(BaseSerializer):
default_error_messages = {
'invalid': _('Invalid data. Expected a dictionary, but got {datatype}.')
}
@property
def fields(self):
if not hasattr(self, '_fields'):
self._fields = BindingDict(self)
for key, value in self.get_fields().items():
self._fields[key] = value
return self._fields
def get_fields(self):
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# Every new serializer is created with a clone of the field instances.
# This allows users to dynamically modify the fields on a serializer
# instance without affecting every other serializer class.
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return copy.deepcopy(self._declared_fields)
def get_validators(self):
return getattr(getattr(self, 'Meta', None), 'validators', [])
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def get_initial(self):
if self._initial_data is not None:
return ReturnDict([
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(field_name, field.get_value(self._initial_data))
for field_name, field in self.fields.items()
if field.get_value(self._initial_data) is not empty
], serializer=self)
return ReturnDict([
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(field.field_name, field.get_initial())
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for field in self.fields.values()
if not field.write_only
], serializer=self)
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def get_value(self, dictionary):
# We override the default field access in order to support
# nested HTML forms.
if html.is_html_input(dictionary):
return html.parse_html_dict(dictionary, prefix=self.field_name)
return dictionary.get(self.field_name, empty)
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def run_validation(self, data=empty):
"""
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We override the default `run_validation`, because the validation
performed by validators and the `.validate()` method should
be coerced into an error dictionary with a 'non_fields_error' key.
"""
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if data is empty:
if getattr(self.root, 'partial', False):
raise SkipField()
if self.required:
self.fail('required')
return self.get_default()
if data is None:
if not self.allow_null:
self.fail('null')
return None
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if not isinstance(data, dict):
message = self.error_messages['invalid'].format(
datatype=type(data).__name__
)
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raise ValidationError({
api_settings.NON_FIELD_ERRORS_KEY: [message]
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})
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value = self.to_internal_value(data)
try:
self.run_validators(value)
value = self.validate(value)
assert value is not None, '.validate() should return the validated data'
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except ValidationError as exc:
if isinstance(exc.detail, dict):
# .validate() errors may be a dict, in which case, use
# standard {key: list of values} style.
raise ValidationError(dict([
(key, value if isinstance(value, list) else [value])
for key, value in exc.detail.items()
]))
elif isinstance(exc.detail, list):
raise ValidationError({
api_settings.NON_FIELD_ERRORS_KEY: exc.detail
})
else:
raise ValidationError({
api_settings.NON_FIELD_ERRORS_KEY: [exc.detail]
})
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return value
def to_internal_value(self, data):
"""
Dict of native values <- Dict of primitive datatypes.
"""
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ret = {}
errors = ReturnDict(serializer=self)
fields = [
field for field in self.fields.values()
if (not field.read_only) or (field.default is not empty)
]
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for field in fields:
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validate_method = getattr(self, 'validate_' + field.field_name, None)
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primitive_value = field.get_value(data)
try:
validated_value = field.run_validation(primitive_value)
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if validate_method is not None:
validated_value = validate_method(validated_value)
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except ValidationError as exc:
errors[field.field_name] = exc.detail
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except SkipField:
pass
else:
set_value(ret, field.source_attrs, validated_value)
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if errors:
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raise ValidationError(errors)
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return ret
def to_representation(self, instance):
"""
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Object instance -> Dict of primitive datatypes.
"""
ret = ReturnDict(serializer=self)
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fields = [field for field in self.fields.values() if not field.write_only]
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for field in fields:
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attribute = field.get_attribute(instance)
if attribute is None:
value = None
else:
value = field.to_representation(attribute)
transform_method = getattr(self, 'transform_' + field.field_name, None)
if transform_method is not None:
value = transform_method(value)
ret[field.field_name] = value
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return ret
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def validate(self, attrs):
return attrs
def __repr__(self):
return representation.serializer_repr(self, indent=1)
# The following are used for accessing `BoundField` instances on the
# serializer, for the purposes of presenting a form-like API onto the
# field values and field errors.
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def __iter__(self):
for field in self.fields.values():
yield self[field.field_name]
def __getitem__(self, key):
field = self.fields[key]
value = self.data.get(key)
error = self.errors.get(key) if hasattr(self, '_errors') else None
if isinstance(field, Serializer):
return NestedBoundField(field, value, error)
return BoundField(field, value, error)
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# There's some replication of `ListField` here,
# but that's probably better than obfuscating the call hierarchy.
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class ListSerializer(BaseSerializer):
child = None
many = True
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def __init__(self, *args, **kwargs):
self.child = kwargs.pop('child', copy.deepcopy(self.child))
assert self.child is not None, '`child` is a required argument.'
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assert not inspect.isclass(self.child), '`child` has not been instantiated.'
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super(ListSerializer, self).__init__(*args, **kwargs)
self.child.bind(field_name='', parent=self)
def get_initial(self):
if self._initial_data is not None:
return self.to_representation(self._initial_data)
return ReturnList(serializer=self)
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def get_value(self, dictionary):
# We override the default field access in order to support
# lists in HTML forms.
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if html.is_html_input(dictionary):
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return html.parse_html_list(dictionary, prefix=self.field_name)
return dictionary.get(self.field_name, empty)
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def to_internal_value(self, data):
"""
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List of dicts of native values <- List of dicts of primitive datatypes.
"""
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if html.is_html_input(data):
data = html.parse_html_list(data)
return [self.child.run_validation(item) for item in data]
def to_representation(self, data):
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"""
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List of object instances -> List of dicts of primitive datatypes.
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"""
iterable = data.all() if (hasattr(data, 'all')) else data
return ReturnList(
[self.child.to_representation(item) for item in iterable],
serializer=self
)
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def create(self, attrs_list):
return [self.child.create(attrs) for attrs in attrs_list]
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def __repr__(self):
return representation.list_repr(self, indent=1)
# ModelSerializer & HyperlinkedModelSerializer
# --------------------------------------------
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class ModelSerializer(Serializer):
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_field_mapping = ClassLookupDict({
models.AutoField: IntegerField,
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models.BigIntegerField: IntegerField,
models.BooleanField: BooleanField,
models.CharField: CharField,
models.CommaSeparatedIntegerField: CharField,
models.DateField: DateField,
models.DateTimeField: DateTimeField,
models.DecimalField: DecimalField,
models.EmailField: EmailField,
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models.Field: ModelField,
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models.FileField: FileField,
models.FloatField: FloatField,
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models.ImageField: ImageField,
models.IntegerField: IntegerField,
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models.NullBooleanField: NullBooleanField,
models.PositiveIntegerField: IntegerField,
models.PositiveSmallIntegerField: IntegerField,
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models.SlugField: SlugField,
models.SmallIntegerField: IntegerField,
models.TextField: CharField,
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models.TimeField: TimeField,
models.URLField: URLField,
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})
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_related_class = PrimaryKeyRelatedField
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def create(self, validated_attrs):
# Check that the user isn't trying to handle a writable nested field.
# If we don't do this explicitly they'd likely get a confusing
# error at the point of calling `Model.objects.create()`.
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assert not any(
isinstance(field, BaseSerializer) and not field.read_only
for field in self.fields.values()
), (
'The `.create()` method does not suport nested writable fields '
'by default. Write an explicit `.create()` method for serializer '
'`%s.%s`, or set `read_only=True` on nested serializer fields.' %
(self.__class__.__module__, self.__class__.__name__)
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)
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ModelClass = self.Meta.model
# Remove many-to-many relationships from validated_attrs.
# They are not valid arguments to the default `.create()` method,
# as they require that the instance has already been saved.
info = model_meta.get_field_info(ModelClass)
many_to_many = {}
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for field_name, relation_info in info.relations.items():
if relation_info.to_many and (field_name in validated_attrs):
many_to_many[field_name] = validated_attrs.pop(field_name)
instance = ModelClass.objects.create(**validated_attrs)
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# Save many-to-many relationships after the instance is created.
if many_to_many:
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for field_name, value in many_to_many.items():
setattr(instance, field_name, value)
return instance
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def update(self, instance, validated_attrs):
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assert not any(
isinstance(field, BaseSerializer) and not field.read_only
for field in self.fields.values()
), (
'The `.update()` method does not suport nested writable fields '
'by default. Write an explicit `.update()` method for serializer '
'`%s.%s`, or set `read_only=True` on nested serializer fields.' %
(self.__class__.__module__, self.__class__.__name__)
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)
for attr, value in validated_attrs.items():
setattr(instance, attr, value)
instance.save()
return instance
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def get_validators(self):
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field_names = set([
field.source for field in self.fields.values()
if (field.source != '*') and ('.' not in field.source)
])
validators = getattr(getattr(self, 'Meta', None), 'validators', [])
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model_class = self.Meta.model
# Note that we make sure to check `unique_together` both on the
# base model class, but also on any parent classes.
for parent_class in [model_class] + list(model_class._meta.parents.keys()):
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for unique_together in parent_class._meta.unique_together:
if field_names.issuperset(set(unique_together)):
validator = UniqueTogetherValidator(
queryset=parent_class._default_manager,
fields=unique_together
)
validators.append(validator)
# Add any unique_for_date/unique_for_month/unique_for_year constraints.
info = model_meta.get_field_info(model_class)
for field_name, field in info.fields_and_pk.items():
if field.unique_for_date and field_name in field_names:
validator = UniqueForDateValidator(
queryset=model_class._default_manager,
field=field_name,
date_field=field.unique_for_date
)
validators.append(validator)
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if field.unique_for_month and field_name in field_names:
validator = UniqueForMonthValidator(
queryset=model_class._default_manager,
field=field_name,
date_field=field.unique_for_month
)
validators.append(validator)
if field.unique_for_year and field_name in field_names:
validator = UniqueForYearValidator(
queryset=model_class._default_manager,
field=field_name,
date_field=field.unique_for_year
)
validators.append(validator)
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return validators
def get_fields(self):
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declared_fields = copy.deepcopy(self._declared_fields)
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ret = SortedDict()
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model = getattr(self.Meta, 'model')
fields = getattr(self.Meta, 'fields', None)
exclude = getattr(self.Meta, 'exclude', None)
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depth = getattr(self.Meta, 'depth', 0)
extra_kwargs = getattr(self.Meta, 'extra_kwargs', {})
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assert not (fields and exclude), "Cannot set both 'fields' and 'exclude'."
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extra_kwargs = self._include_additional_options(extra_kwargs)
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# Retrieve metadata about fields & relationships on the model class.
info = model_meta.get_field_info(model)
# Use the default set of field names if none is supplied explicitly.
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if fields is None:
fields = self._get_default_field_names(declared_fields, info)
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exclude = getattr(self.Meta, 'exclude', None)
if exclude is not None:
for field_name in exclude:
fields.remove(field_name)
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# Determine the set of model fields, and the fields that they map to.
# We actually only need this to deal with the slightly awkward case
# of supporting `unique_for_date`/`unique_for_month`/`unique_for_year`.
model_field_mapping = {}
for field_name in fields:
if field_name in declared_fields:
field = declared_fields[field_name]
source = field.source or field_name
else:
try:
source = extra_kwargs[field_name]['source']
except KeyError:
source = field_name
# Model fields will always have a simple source mapping,
# they can't be nested attribute lookups.
if '.' not in source and source != '*':
model_field_mapping[source] = field_name
# Determine if we need any additional `HiddenField` or extra keyword
# arguments to deal with `unique_for` dates that are required to
# be in the input data in order to validate it.
unique_fields = {}
for model_field_name, field_name in model_field_mapping.items():
try:
model_field = model._meta.get_field(model_field_name)
except FieldDoesNotExist:
continue
# Deal with each of the `unique_for_*` cases.
for date_field_name in (
model_field.unique_for_date,
model_field.unique_for_month,
model_field.unique_for_year
):
if date_field_name is None:
continue
# Get the model field that is refered too.
date_field = model._meta.get_field(date_field_name)
if date_field.auto_now_add:
default = CreateOnlyDefault(timezone.now)
elif date_field.auto_now:
default = timezone.now
elif date_field.has_default():
default = model_field.default
else:
default = empty
if date_field_name in model_field_mapping:
# The corresponding date field is present in the serializer
if date_field_name not in extra_kwargs:
extra_kwargs[date_field_name] = {}
if default is empty:
if 'required' not in extra_kwargs[date_field_name]:
extra_kwargs[date_field_name]['required'] = True
else:
if 'default' not in extra_kwargs[date_field_name]:
extra_kwargs[date_field_name]['default'] = default
else:
# The corresponding date field is not present in the,
# serializer. We have a default to use for the date, so
# add in a hidden field that populates it.
unique_fields[date_field_name] = HiddenField(default=default)
# Now determine the fields that should be included on the serializer.
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for field_name in fields:
if field_name in declared_fields:
# Field is explicitly declared on the class, use that.
ret[field_name] = declared_fields[field_name]
continue
elif field_name in info.fields_and_pk:
# Create regular model fields.
model_field = info.fields_and_pk[field_name]
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field_cls = self._field_mapping[model_field]
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kwargs = get_field_kwargs(field_name, model_field)
if 'choices' in kwargs:
# Fields with choices get coerced into `ChoiceField`
# instead of using their regular typed field.
field_cls = ChoiceField
if not issubclass(field_cls, ModelField):
# `model_field` is only valid for the fallback case of
# `ModelField`, which is used when no other typed field
# matched to the model field.
kwargs.pop('model_field', None)
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if not issubclass(field_cls, CharField):
# `allow_blank` is only valid for textual fields.
kwargs.pop('allow_blank', None)
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elif field_name in info.relations:
# Create forward and reverse relationships.
relation_info = info.relations[field_name]
if depth:
field_cls = self._get_nested_class(depth, relation_info)
kwargs = get_nested_relation_kwargs(relation_info)
else:
field_cls = self._related_class
kwargs = get_relation_kwargs(field_name, relation_info)
# `view_name` is only valid for hyperlinked relationships.
if not issubclass(field_cls, HyperlinkedRelatedField):
kwargs.pop('view_name', None)
elif hasattr(model, field_name):
# Create a read only field for model methods and properties.
field_cls = ReadOnlyField
kwargs = {}
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elif field_name == api_settings.URL_FIELD_NAME:
# Create the URL field.
field_cls = HyperlinkedIdentityField
kwargs = get_url_kwargs(model)
else:
raise ImproperlyConfigured(
'Field name `%s` is not valid for model `%s`.' %
(field_name, model.__class__.__name__)
)
# Check that any fields declared on the class are
# also explicity included in `Meta.fields`.
missing_fields = set(declared_fields.keys()) - set(fields)
if missing_fields:
missing_field = list(missing_fields)[0]
raise ImproperlyConfigured(
'Field `%s` has been declared on serializer `%s`, but '
'is missing from `Meta.fields`.' %
(missing_field, self.__class__.__name__)
)
# Populate any kwargs defined in `Meta.extra_kwargs`
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extras = extra_kwargs.get(field_name, {})
if extras.get('read_only', False):
for attr in [
'required', 'default', 'allow_blank', 'allow_null',
'min_length', 'max_length', 'min_value', 'max_value',
'validators', 'queryset'
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]:
kwargs.pop(attr, None)
kwargs.update(extras)
# Create the serializer field.
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ret[field_name] = field_cls(**kwargs)
for field_name, field in unique_fields.items():
ret[field_name] = field
return ret
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def _include_additional_options(self, extra_kwargs):
read_only_fields = getattr(self.Meta, 'read_only_fields', None)
if read_only_fields is not None:
for field_name in read_only_fields:
kwargs = extra_kwargs.get(field_name, {})
kwargs['read_only'] = True
extra_kwargs[field_name] = kwargs
# These are all pending deprecation.
write_only_fields = getattr(self.Meta, 'write_only_fields', None)
if write_only_fields is not None:
warnings.warn(
"The `Meta.write_only_fields` option is pending deprecation. "
"Use `Meta.extra_kwargs={<field_name>: {'write_only': True}}` instead.",
PendingDeprecationWarning,
stacklevel=3
)
for field_name in write_only_fields:
kwargs = extra_kwargs.get(field_name, {})
kwargs['write_only'] = True
extra_kwargs[field_name] = kwargs
view_name = getattr(self.Meta, 'view_name', None)
if view_name is not None:
warnings.warn(
"The `Meta.view_name` option is pending deprecation. "
"Use `Meta.extra_kwargs={'url': {'view_name': ...}}` instead.",
PendingDeprecationWarning,
stacklevel=3
)
kwargs = extra_kwargs.get(api_settings.URL_FIELD_NAME, {})
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kwargs['view_name'] = view_name
extra_kwargs[api_settings.URL_FIELD_NAME] = kwargs
lookup_field = getattr(self.Meta, 'lookup_field', None)
if lookup_field is not None:
warnings.warn(
"The `Meta.lookup_field` option is pending deprecation. "
"Use `Meta.extra_kwargs={'url': {'lookup_field': ...}}` instead.",
PendingDeprecationWarning,
stacklevel=3
)
kwargs = extra_kwargs.get(api_settings.URL_FIELD_NAME, {})
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kwargs['lookup_field'] = lookup_field
extra_kwargs[api_settings.URL_FIELD_NAME] = kwargs
return extra_kwargs
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def _get_default_field_names(self, declared_fields, model_info):
return (
[model_info.pk.name] +
list(declared_fields.keys()) +
list(model_info.fields.keys()) +
list(model_info.forward_relations.keys())
)
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def _get_nested_class(self, nested_depth, relation_info):
class NestedSerializer(ModelSerializer):
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class Meta:
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model = relation_info.related
depth = nested_depth
return NestedSerializer
class HyperlinkedModelSerializer(ModelSerializer):
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_related_class = HyperlinkedRelatedField
def _get_default_field_names(self, declared_fields, model_info):
return (
[api_settings.URL_FIELD_NAME] +
list(declared_fields.keys()) +
list(model_info.fields.keys()) +
list(model_info.forward_relations.keys())
)
def _get_nested_class(self, nested_depth, relation_info):
class NestedSerializer(HyperlinkedModelSerializer):
class Meta:
model = relation_info.related
depth = nested_depth
return NestedSerializer