mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-11-26 19:43:59 +03:00
140f8620ae
This avoids AppRegistryNotReady problems in Django 1.7 with nested serializers, which are instantiated at import time, possibly before Django's app registry is fully populated.
1164 lines
41 KiB
Python
1164 lines
41 KiB
Python
"""
|
|
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
|
|
response content is handled by parsers and renderers.
|
|
"""
|
|
from __future__ import unicode_literals
|
|
import copy
|
|
import datetime
|
|
import inspect
|
|
import types
|
|
from decimal import Decimal
|
|
from django.contrib.contenttypes.generic import GenericForeignKey
|
|
from django.core.paginator import Page
|
|
from django.db import models
|
|
from django.forms import widgets
|
|
from django.utils import six
|
|
from django.utils.datastructures import SortedDict
|
|
from django.utils.functional import cached_property
|
|
from django.core.exceptions import ObjectDoesNotExist
|
|
from rest_framework.settings import api_settings
|
|
|
|
|
|
# Note: We do the following so that users of the framework can use this style:
|
|
#
|
|
# example_field = serializers.CharField(...)
|
|
#
|
|
# This helps keep the separation between model fields, form fields, and
|
|
# serializer fields more explicit.
|
|
|
|
from rest_framework.relations import * # NOQA
|
|
from rest_framework.fields import * # NOQA
|
|
|
|
|
|
def _resolve_model(obj):
|
|
"""
|
|
Resolve supplied `obj` to a Django model class.
|
|
|
|
`obj` must be a Django model class itself, or a string
|
|
representation of one. Useful in situtations like GH #1225 where
|
|
Django may not have resolved a string-based reference to a model in
|
|
another model's foreign key definition.
|
|
|
|
String representations should have the format:
|
|
'appname.ModelName'
|
|
"""
|
|
if isinstance(obj, six.string_types) and len(obj.split('.')) == 2:
|
|
app_name, model_name = obj.split('.')
|
|
return models.get_model(app_name, model_name)
|
|
elif inspect.isclass(obj) and issubclass(obj, models.Model):
|
|
return obj
|
|
else:
|
|
raise ValueError("{0} is not a Django model".format(obj))
|
|
|
|
|
|
def pretty_name(name):
|
|
"""Converts 'first_name' to 'First name'"""
|
|
if not name:
|
|
return ''
|
|
return name.replace('_', ' ').capitalize()
|
|
|
|
|
|
class RelationsList(list):
|
|
_deleted = []
|
|
|
|
|
|
class NestedValidationError(ValidationError):
|
|
"""
|
|
The default ValidationError behavior is to stringify each item in the list
|
|
if the messages are a list of error messages.
|
|
|
|
In the case of nested serializers, where the parent has many children,
|
|
then the child's `serializer.errors` will be a list of dicts. In the case
|
|
of a single child, the `serializer.errors` will be a dict.
|
|
|
|
We need to override the default behavior to get properly nested error dicts.
|
|
"""
|
|
|
|
def __init__(self, message):
|
|
if isinstance(message, dict):
|
|
self._messages = [message]
|
|
else:
|
|
self._messages = message
|
|
|
|
@property
|
|
def messages(self):
|
|
return self._messages
|
|
|
|
|
|
class DictWithMetadata(dict):
|
|
"""
|
|
A dict-like object, that can have additional properties attached.
|
|
"""
|
|
def __getstate__(self):
|
|
"""
|
|
Used by pickle (e.g., caching).
|
|
Overridden to remove the metadata from the dict, since it shouldn't be
|
|
pickled and may in some instances be unpickleable.
|
|
"""
|
|
return dict(self)
|
|
|
|
|
|
class SortedDictWithMetadata(SortedDict):
|
|
"""
|
|
A sorted dict-like object, that can have additional properties attached.
|
|
"""
|
|
def __getstate__(self):
|
|
"""
|
|
Used by pickle (e.g., caching).
|
|
Overriden to remove the metadata from the dict, since it shouldn't be
|
|
pickle and may in some instances be unpickleable.
|
|
"""
|
|
return SortedDict(self).__dict__
|
|
|
|
|
|
def _is_protected_type(obj):
|
|
"""
|
|
True if the object is a native datatype that does not need to
|
|
be serialized further.
|
|
"""
|
|
return isinstance(obj, (
|
|
types.NoneType,
|
|
int, long,
|
|
datetime.datetime, datetime.date, datetime.time,
|
|
float, Decimal,
|
|
basestring)
|
|
)
|
|
|
|
|
|
def _get_declared_fields(bases, attrs):
|
|
"""
|
|
Create a list of serializer field instances from the passed in 'attrs',
|
|
plus any fields on the base classes (in 'bases').
|
|
|
|
Note that all fields from the base classes are used.
|
|
"""
|
|
fields = [(field_name, attrs.pop(field_name))
|
|
for field_name, obj in list(six.iteritems(attrs))
|
|
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, 'base_fields'):
|
|
fields = list(base.base_fields.items()) + fields
|
|
|
|
return SortedDict(fields)
|
|
|
|
|
|
class SerializerMetaclass(type):
|
|
def __new__(cls, name, bases, attrs):
|
|
attrs['base_fields'] = _get_declared_fields(bases, attrs)
|
|
return super(SerializerMetaclass, cls).__new__(cls, name, bases, attrs)
|
|
|
|
|
|
class SerializerOptions(object):
|
|
"""
|
|
Meta class options for Serializer
|
|
"""
|
|
def __init__(self, meta):
|
|
self.depth = getattr(meta, 'depth', 0)
|
|
self.fields = getattr(meta, 'fields', ())
|
|
self.exclude = getattr(meta, 'exclude', ())
|
|
|
|
|
|
class BaseSerializer(WritableField):
|
|
"""
|
|
This is the Serializer implementation.
|
|
We need to implement it as `BaseSerializer` due to metaclass magicks.
|
|
"""
|
|
class Meta(object):
|
|
pass
|
|
|
|
_options_class = SerializerOptions
|
|
_dict_class = SortedDictWithMetadata
|
|
|
|
def __init__(self, instance=None, data=None, files=None,
|
|
context=None, partial=False, many=False,
|
|
allow_add_remove=False, **kwargs):
|
|
super(BaseSerializer, self).__init__(**kwargs)
|
|
self.opts = self._options_class(self.Meta)
|
|
self.parent = None
|
|
self.root = None
|
|
self.partial = partial
|
|
self.many = many
|
|
self.allow_add_remove = allow_add_remove
|
|
|
|
self.context = context or {}
|
|
|
|
self.init_data = data
|
|
self.init_files = files
|
|
self.object = instance
|
|
|
|
self._data = None
|
|
self._files = None
|
|
self._errors = None
|
|
|
|
if many and instance is not None and not hasattr(instance, '__iter__'):
|
|
raise ValueError('instance should be a queryset or other iterable with many=True')
|
|
|
|
if allow_add_remove and not many:
|
|
raise ValueError('allow_add_remove should only be used for bulk updates, but you have not set many=True')
|
|
|
|
#####
|
|
# Methods to determine which fields to use when (de)serializing objects.
|
|
|
|
@cached_property
|
|
def fields(self):
|
|
return self.get_fields()
|
|
|
|
def get_default_fields(self):
|
|
"""
|
|
Return the complete set of default fields for the object, as a dict.
|
|
"""
|
|
return {}
|
|
|
|
def get_fields(self):
|
|
"""
|
|
Returns the complete set of fields for the object as a dict.
|
|
|
|
This will be the set of any explicitly declared fields,
|
|
plus the set of fields returned by get_default_fields().
|
|
"""
|
|
ret = SortedDict()
|
|
|
|
# Get the explicitly declared fields
|
|
base_fields = copy.deepcopy(self.base_fields)
|
|
for key, field in base_fields.items():
|
|
ret[key] = field
|
|
|
|
# Add in the default fields
|
|
default_fields = self.get_default_fields()
|
|
for key, val in default_fields.items():
|
|
if key not in ret:
|
|
ret[key] = val
|
|
|
|
# If 'fields' is specified, use those fields, in that order.
|
|
if self.opts.fields:
|
|
assert isinstance(self.opts.fields, (list, tuple)), '`fields` must be a list or tuple'
|
|
new = SortedDict()
|
|
for key in self.opts.fields:
|
|
new[key] = ret[key]
|
|
ret = new
|
|
|
|
# Remove anything in 'exclude'
|
|
if self.opts.exclude:
|
|
assert isinstance(self.opts.exclude, (list, tuple)), '`exclude` must be a list or tuple'
|
|
for key in self.opts.exclude:
|
|
ret.pop(key, None)
|
|
|
|
for key, field in ret.items():
|
|
field.initialize(parent=self, field_name=key)
|
|
|
|
return ret
|
|
|
|
#####
|
|
# Methods to convert or revert from objects <--> primitive representations.
|
|
|
|
def get_field_key(self, field_name):
|
|
"""
|
|
Return the key that should be used for a given field.
|
|
"""
|
|
return field_name
|
|
|
|
def restore_fields(self, data, files):
|
|
"""
|
|
Core of deserialization, together with `restore_object`.
|
|
Converts a dictionary of data into a dictionary of deserialized fields.
|
|
"""
|
|
reverted_data = {}
|
|
|
|
if data is not None and not isinstance(data, dict):
|
|
self._errors['non_field_errors'] = ['Invalid data']
|
|
return None
|
|
|
|
for field_name, field in self.fields.items():
|
|
field.initialize(parent=self, field_name=field_name)
|
|
try:
|
|
field.field_from_native(data, files, field_name, reverted_data)
|
|
except ValidationError as err:
|
|
self._errors[field_name] = list(err.messages)
|
|
|
|
return reverted_data
|
|
|
|
def perform_validation(self, attrs):
|
|
"""
|
|
Run `validate_<fieldname>()` and `validate()` methods on the serializer
|
|
"""
|
|
for field_name, field in self.fields.items():
|
|
if field_name in self._errors:
|
|
continue
|
|
|
|
source = field.source or field_name
|
|
if self.partial and source not in attrs:
|
|
continue
|
|
try:
|
|
validate_method = getattr(self, 'validate_%s' % field_name, None)
|
|
if validate_method:
|
|
attrs = validate_method(attrs, source)
|
|
except ValidationError as err:
|
|
self._errors[field_name] = self._errors.get(field_name, []) + list(err.messages)
|
|
|
|
# If there are already errors, we don't run .validate() because
|
|
# field-validation failed and thus `attrs` may not be complete.
|
|
# which in turn can cause inconsistent validation errors.
|
|
if not self._errors:
|
|
try:
|
|
attrs = self.validate(attrs)
|
|
except ValidationError as err:
|
|
if hasattr(err, 'message_dict'):
|
|
for field_name, error_messages in err.message_dict.items():
|
|
self._errors[field_name] = self._errors.get(field_name, []) + list(error_messages)
|
|
elif hasattr(err, 'messages'):
|
|
self._errors['non_field_errors'] = err.messages
|
|
|
|
return attrs
|
|
|
|
def validate(self, attrs):
|
|
"""
|
|
Stub method, to be overridden in Serializer subclasses
|
|
"""
|
|
return attrs
|
|
|
|
def restore_object(self, attrs, instance=None):
|
|
"""
|
|
Deserialize a dictionary of attributes into an object instance.
|
|
You should override this method to control how deserialized objects
|
|
are instantiated.
|
|
"""
|
|
if instance is not None:
|
|
instance.update(attrs)
|
|
return instance
|
|
return attrs
|
|
|
|
def to_native(self, obj):
|
|
"""
|
|
Serialize objects -> primitives.
|
|
"""
|
|
ret = self._dict_class()
|
|
ret.fields = self._dict_class()
|
|
|
|
for field_name, field in self.fields.items():
|
|
if field.read_only and obj is None:
|
|
continue
|
|
field.initialize(parent=self, field_name=field_name)
|
|
key = self.get_field_key(field_name)
|
|
value = field.field_to_native(obj, field_name)
|
|
method = getattr(self, 'transform_%s' % field_name, None)
|
|
if callable(method):
|
|
value = method(obj, value)
|
|
if not getattr(field, 'write_only', False):
|
|
ret[key] = value
|
|
ret.fields[key] = self.augment_field(field, field_name, key, value)
|
|
|
|
return ret
|
|
|
|
def from_native(self, data, files=None):
|
|
"""
|
|
Deserialize primitives -> objects.
|
|
"""
|
|
self._errors = {}
|
|
|
|
if data is not None or files is not None:
|
|
attrs = self.restore_fields(data, files)
|
|
if attrs is not None:
|
|
attrs = self.perform_validation(attrs)
|
|
else:
|
|
self._errors['non_field_errors'] = ['No input provided']
|
|
|
|
if not self._errors:
|
|
return self.restore_object(attrs, instance=getattr(self, 'object', None))
|
|
|
|
def augment_field(self, field, field_name, key, value):
|
|
# This horrible stuff is to manage serializers rendering to HTML
|
|
field._errors = self._errors.get(key) if self._errors else None
|
|
field._name = field_name
|
|
field._value = self.init_data.get(key) if self._errors and self.init_data else value
|
|
if not field.label:
|
|
field.label = pretty_name(key)
|
|
return field
|
|
|
|
def field_to_native(self, obj, field_name):
|
|
"""
|
|
Override default so that the serializer can be used as a nested field
|
|
across relationships.
|
|
"""
|
|
if self.write_only:
|
|
return None
|
|
|
|
if self.source == '*':
|
|
return self.to_native(obj)
|
|
|
|
# Get the raw field value
|
|
try:
|
|
source = self.source or field_name
|
|
value = obj
|
|
|
|
for component in source.split('.'):
|
|
if value is None:
|
|
break
|
|
value = get_component(value, component)
|
|
except ObjectDoesNotExist:
|
|
return None
|
|
|
|
if is_simple_callable(getattr(value, 'all', None)):
|
|
return [self.to_native(item) for item in value.all()]
|
|
|
|
if value is None:
|
|
return None
|
|
|
|
if self.many:
|
|
return [self.to_native(item) for item in value]
|
|
return self.to_native(value)
|
|
|
|
def field_from_native(self, data, files, field_name, into):
|
|
"""
|
|
Override default so that the serializer can be used as a writable
|
|
nested field across relationships.
|
|
"""
|
|
if self.read_only:
|
|
return
|
|
|
|
try:
|
|
value = data[field_name]
|
|
except KeyError:
|
|
if self.default is not None and not self.partial:
|
|
# Note: partial updates shouldn't set defaults
|
|
value = copy.deepcopy(self.default)
|
|
else:
|
|
if self.required:
|
|
raise ValidationError(self.error_messages['required'])
|
|
return
|
|
|
|
if self.source == '*':
|
|
if value:
|
|
reverted_data = self.restore_fields(value, {})
|
|
if not self._errors:
|
|
into.update(reverted_data)
|
|
else:
|
|
if value in (None, ''):
|
|
into[(self.source or field_name)] = None
|
|
else:
|
|
# Set the serializer object if it exists
|
|
obj = get_component(self.parent.object, self.source or field_name) if self.parent.object else None
|
|
|
|
# If we have a model manager or similar object then we need
|
|
# to iterate through each instance.
|
|
if (
|
|
self.many and
|
|
not hasattr(obj, '__iter__') and
|
|
is_simple_callable(getattr(obj, 'all', None))
|
|
):
|
|
obj = obj.all()
|
|
|
|
kwargs = {
|
|
'instance': obj,
|
|
'data': value,
|
|
'context': self.context,
|
|
'partial': self.partial,
|
|
'many': self.many,
|
|
'allow_add_remove': self.allow_add_remove
|
|
}
|
|
serializer = self.__class__(**kwargs)
|
|
|
|
if serializer.is_valid():
|
|
into[self.source or field_name] = serializer.object
|
|
else:
|
|
# Propagate errors up to our parent
|
|
raise NestedValidationError(serializer.errors)
|
|
|
|
def get_identity(self, data):
|
|
"""
|
|
This hook is required for bulk update.
|
|
It is used to determine the canonical identity of a given object.
|
|
|
|
Note that the data has not been validated at this point, so we need
|
|
to make sure that we catch any cases of incorrect datatypes being
|
|
passed to this method.
|
|
"""
|
|
try:
|
|
return data.get('id', None)
|
|
except AttributeError:
|
|
return None
|
|
|
|
@property
|
|
def errors(self):
|
|
"""
|
|
Run deserialization and return error data,
|
|
setting self.object if no errors occurred.
|
|
"""
|
|
if self._errors is None:
|
|
data, files = self.init_data, self.init_files
|
|
|
|
if self.many is not None:
|
|
many = self.many
|
|
else:
|
|
many = hasattr(data, '__iter__') and not isinstance(data, (Page, dict, six.text_type))
|
|
if many:
|
|
warnings.warn('Implicit list/queryset serialization is deprecated. '
|
|
'Use the `many=True` flag when instantiating the serializer.',
|
|
DeprecationWarning, stacklevel=3)
|
|
|
|
if many:
|
|
ret = RelationsList()
|
|
errors = []
|
|
update = self.object is not None
|
|
|
|
if update:
|
|
# If this is a bulk update we need to map all the objects
|
|
# to a canonical identity so we can determine which
|
|
# individual object is being updated for each item in the
|
|
# incoming data
|
|
objects = self.object
|
|
identities = [self.get_identity(self.to_native(obj)) for obj in objects]
|
|
identity_to_objects = dict(zip(identities, objects))
|
|
|
|
if hasattr(data, '__iter__') and not isinstance(data, (dict, six.text_type)):
|
|
for item in data:
|
|
if update:
|
|
# Determine which object we're updating
|
|
identity = self.get_identity(item)
|
|
self.object = identity_to_objects.pop(identity, None)
|
|
if self.object is None and not self.allow_add_remove:
|
|
ret.append(None)
|
|
errors.append({'non_field_errors': ['Cannot create a new item, only existing items may be updated.']})
|
|
continue
|
|
|
|
ret.append(self.from_native(item, None))
|
|
errors.append(self._errors)
|
|
|
|
if update and self.allow_add_remove:
|
|
ret._deleted = identity_to_objects.values()
|
|
|
|
self._errors = any(errors) and errors or []
|
|
else:
|
|
self._errors = {'non_field_errors': ['Expected a list of items.']}
|
|
else:
|
|
ret = self.from_native(data, files)
|
|
|
|
if not self._errors:
|
|
self.object = ret
|
|
|
|
return self._errors
|
|
|
|
def is_valid(self):
|
|
return not self.errors
|
|
|
|
@property
|
|
def data(self):
|
|
"""
|
|
Returns the serialized data on the serializer.
|
|
"""
|
|
if self._data is None:
|
|
obj = self.object
|
|
|
|
if self.many is not None:
|
|
many = self.many
|
|
else:
|
|
many = hasattr(obj, '__iter__') and not isinstance(obj, (Page, dict))
|
|
if many:
|
|
warnings.warn('Implicit list/queryset serialization is deprecated. '
|
|
'Use the `many=True` flag when instantiating the serializer.',
|
|
DeprecationWarning, stacklevel=2)
|
|
|
|
if many:
|
|
self._data = [self.to_native(item) for item in obj]
|
|
else:
|
|
self._data = self.to_native(obj)
|
|
|
|
return self._data
|
|
|
|
def save_object(self, obj, **kwargs):
|
|
obj.save(**kwargs)
|
|
|
|
def delete_object(self, obj):
|
|
obj.delete()
|
|
|
|
def save(self, **kwargs):
|
|
"""
|
|
Save the deserialized object and return it.
|
|
"""
|
|
# Clear cached _data, which may be invalidated by `save()`
|
|
self._data = None
|
|
|
|
if isinstance(self.object, list):
|
|
[self.save_object(item, **kwargs) for item in self.object]
|
|
|
|
if self.object._deleted:
|
|
[self.delete_object(item) for item in self.object._deleted]
|
|
else:
|
|
self.save_object(self.object, **kwargs)
|
|
|
|
return self.object
|
|
|
|
def metadata(self):
|
|
"""
|
|
Return a dictionary of metadata about the fields on the serializer.
|
|
Useful for things like responding to OPTIONS requests, or generating
|
|
API schemas for auto-documentation.
|
|
"""
|
|
return SortedDict(
|
|
[
|
|
(field_name, field.metadata())
|
|
for field_name, field in six.iteritems(self.fields)
|
|
]
|
|
)
|
|
|
|
|
|
class Serializer(six.with_metaclass(SerializerMetaclass, BaseSerializer)):
|
|
pass
|
|
|
|
|
|
class ModelSerializerOptions(SerializerOptions):
|
|
"""
|
|
Meta class options for ModelSerializer
|
|
"""
|
|
def __init__(self, meta):
|
|
super(ModelSerializerOptions, self).__init__(meta)
|
|
self.model = getattr(meta, 'model', None)
|
|
self.read_only_fields = getattr(meta, 'read_only_fields', ())
|
|
self.write_only_fields = getattr(meta, 'write_only_fields', ())
|
|
|
|
|
|
def _get_class_mapping(mapping, obj):
|
|
"""
|
|
Takes a dictionary with classes as keys, and an object.
|
|
Traverses the object's inheritance hierarchy in method
|
|
resolution order, and returns the first matching value
|
|
from the dictionary or None.
|
|
|
|
"""
|
|
return next(
|
|
(mapping[cls] for cls in inspect.getmro(obj.__class__) if cls in mapping),
|
|
None
|
|
)
|
|
|
|
|
|
class ModelSerializer(Serializer):
|
|
"""
|
|
A serializer that deals with model instances and querysets.
|
|
"""
|
|
_options_class = ModelSerializerOptions
|
|
|
|
field_mapping = {
|
|
models.AutoField: IntegerField,
|
|
models.FloatField: FloatField,
|
|
models.IntegerField: IntegerField,
|
|
models.PositiveIntegerField: IntegerField,
|
|
models.SmallIntegerField: IntegerField,
|
|
models.PositiveSmallIntegerField: IntegerField,
|
|
models.DateTimeField: DateTimeField,
|
|
models.DateField: DateField,
|
|
models.TimeField: TimeField,
|
|
models.DecimalField: DecimalField,
|
|
models.EmailField: EmailField,
|
|
models.CharField: CharField,
|
|
models.URLField: URLField,
|
|
models.SlugField: SlugField,
|
|
models.TextField: CharField,
|
|
models.CommaSeparatedIntegerField: CharField,
|
|
models.BooleanField: BooleanField,
|
|
models.NullBooleanField: BooleanField,
|
|
models.FileField: FileField,
|
|
models.ImageField: ImageField,
|
|
}
|
|
|
|
def get_default_fields(self):
|
|
"""
|
|
Return all the fields that should be serialized for the model.
|
|
"""
|
|
|
|
cls = self.opts.model
|
|
assert cls is not None, (
|
|
"Serializer class '%s' is missing 'model' Meta option" %
|
|
self.__class__.__name__
|
|
)
|
|
opts = cls._meta.concrete_model._meta
|
|
ret = SortedDict()
|
|
nested = bool(self.opts.depth)
|
|
|
|
# Deal with adding the primary key field
|
|
pk_field = opts.pk
|
|
while pk_field.rel and pk_field.rel.parent_link:
|
|
# If model is a child via multitable inheritance, use parent's pk
|
|
pk_field = pk_field.rel.to._meta.pk
|
|
|
|
serializer_pk_field = self.get_pk_field(pk_field)
|
|
if serializer_pk_field:
|
|
ret[pk_field.name] = serializer_pk_field
|
|
|
|
# Deal with forward relationships
|
|
forward_rels = [field for field in opts.fields if field.serialize]
|
|
forward_rels += [field for field in opts.many_to_many if field.serialize]
|
|
|
|
for model_field in forward_rels:
|
|
has_through_model = False
|
|
|
|
if model_field.rel:
|
|
to_many = isinstance(model_field,
|
|
models.fields.related.ManyToManyField)
|
|
related_model = _resolve_model(model_field.rel.to)
|
|
|
|
if to_many and not model_field.rel.through._meta.auto_created:
|
|
has_through_model = True
|
|
|
|
if model_field.rel and nested:
|
|
if len(inspect.getargspec(self.get_nested_field).args) == 2:
|
|
warnings.warn(
|
|
'The `get_nested_field(model_field)` call signature '
|
|
'is deprecated. '
|
|
'Use `get_nested_field(model_field, related_model, '
|
|
'to_many) instead',
|
|
DeprecationWarning
|
|
)
|
|
field = self.get_nested_field(model_field)
|
|
else:
|
|
field = self.get_nested_field(model_field, related_model, to_many)
|
|
elif model_field.rel:
|
|
if len(inspect.getargspec(self.get_nested_field).args) == 3:
|
|
warnings.warn(
|
|
'The `get_related_field(model_field, to_many)` call '
|
|
'signature is deprecated. '
|
|
'Use `get_related_field(model_field, related_model, '
|
|
'to_many) instead',
|
|
DeprecationWarning
|
|
)
|
|
field = self.get_related_field(model_field, to_many=to_many)
|
|
else:
|
|
field = self.get_related_field(model_field, related_model, to_many)
|
|
else:
|
|
field = self.get_field(model_field)
|
|
|
|
if field:
|
|
if has_through_model:
|
|
field.read_only = True
|
|
|
|
ret[model_field.name] = field
|
|
|
|
# Deal with reverse relationships
|
|
if not self.opts.fields:
|
|
reverse_rels = []
|
|
else:
|
|
# Reverse relationships are only included if they are explicitly
|
|
# present in the `fields` option on the serializer
|
|
reverse_rels = opts.get_all_related_objects()
|
|
reverse_rels += opts.get_all_related_many_to_many_objects()
|
|
|
|
for relation in reverse_rels:
|
|
accessor_name = relation.get_accessor_name()
|
|
if not self.opts.fields or accessor_name not in self.opts.fields:
|
|
continue
|
|
related_model = relation.model
|
|
to_many = relation.field.rel.multiple
|
|
has_through_model = False
|
|
is_m2m = isinstance(relation.field,
|
|
models.fields.related.ManyToManyField)
|
|
|
|
if (
|
|
is_m2m and
|
|
hasattr(relation.field.rel, 'through') and
|
|
not relation.field.rel.through._meta.auto_created
|
|
):
|
|
has_through_model = True
|
|
|
|
if nested:
|
|
field = self.get_nested_field(None, related_model, to_many)
|
|
else:
|
|
field = self.get_related_field(None, related_model, to_many)
|
|
|
|
if field:
|
|
if has_through_model:
|
|
field.read_only = True
|
|
|
|
ret[accessor_name] = field
|
|
|
|
# Ensure that 'read_only_fields' is an iterable
|
|
assert isinstance(self.opts.read_only_fields, (list, tuple)), '`read_only_fields` must be a list or tuple'
|
|
|
|
# Add the `read_only` flag to any fields that have been specified
|
|
# in the `read_only_fields` option
|
|
for field_name in self.opts.read_only_fields:
|
|
assert field_name not in self.base_fields.keys(), (
|
|
"field '%s' on serializer '%s' specified in "
|
|
"`read_only_fields`, but also added "
|
|
"as an explicit field. Remove it from `read_only_fields`." %
|
|
(field_name, self.__class__.__name__))
|
|
assert field_name in ret, (
|
|
"Non-existant field '%s' specified in `read_only_fields` "
|
|
"on serializer '%s'." %
|
|
(field_name, self.__class__.__name__))
|
|
ret[field_name].read_only = True
|
|
|
|
# Ensure that 'write_only_fields' is an iterable
|
|
assert isinstance(self.opts.write_only_fields, (list, tuple)), '`write_only_fields` must be a list or tuple'
|
|
|
|
for field_name in self.opts.write_only_fields:
|
|
assert field_name not in self.base_fields.keys(), (
|
|
"field '%s' on serializer '%s' specified in "
|
|
"`write_only_fields`, but also added "
|
|
"as an explicit field. Remove it from `write_only_fields`." %
|
|
(field_name, self.__class__.__name__))
|
|
assert field_name in ret, (
|
|
"Non-existant field '%s' specified in `write_only_fields` "
|
|
"on serializer '%s'." %
|
|
(field_name, self.__class__.__name__))
|
|
ret[field_name].write_only = True
|
|
|
|
return ret
|
|
|
|
def get_pk_field(self, model_field):
|
|
"""
|
|
Returns a default instance of the pk field.
|
|
"""
|
|
return self.get_field(model_field)
|
|
|
|
def get_nested_field(self, model_field, related_model, to_many):
|
|
"""
|
|
Creates a default instance of a nested relational field.
|
|
|
|
Note that model_field will be `None` for reverse relationships.
|
|
"""
|
|
class NestedModelSerializer(ModelSerializer):
|
|
class Meta:
|
|
model = related_model
|
|
depth = self.opts.depth - 1
|
|
|
|
return NestedModelSerializer(many=to_many)
|
|
|
|
def get_related_field(self, model_field, related_model, to_many):
|
|
"""
|
|
Creates a default instance of a flat relational field.
|
|
|
|
Note that model_field will be `None` for reverse relationships.
|
|
"""
|
|
# TODO: filter queryset using:
|
|
# .using(db).complex_filter(self.rel.limit_choices_to)
|
|
|
|
kwargs = {
|
|
'queryset': related_model._default_manager,
|
|
'many': to_many
|
|
}
|
|
|
|
if model_field:
|
|
kwargs['required'] = not(model_field.null or model_field.blank)
|
|
if model_field.help_text is not None:
|
|
kwargs['help_text'] = model_field.help_text
|
|
if model_field.verbose_name is not None:
|
|
kwargs['label'] = model_field.verbose_name
|
|
|
|
if not model_field.editable:
|
|
kwargs['read_only'] = True
|
|
|
|
if model_field.verbose_name is not None:
|
|
kwargs['label'] = model_field.verbose_name
|
|
|
|
if model_field.help_text is not None:
|
|
kwargs['help_text'] = model_field.help_text
|
|
|
|
return PrimaryKeyRelatedField(**kwargs)
|
|
|
|
def get_field(self, model_field):
|
|
"""
|
|
Creates a default instance of a basic non-relational field.
|
|
"""
|
|
kwargs = {}
|
|
|
|
if model_field.null or model_field.blank:
|
|
kwargs['required'] = False
|
|
|
|
if isinstance(model_field, models.AutoField) or not model_field.editable:
|
|
kwargs['read_only'] = True
|
|
|
|
if model_field.has_default():
|
|
kwargs['default'] = model_field.get_default()
|
|
|
|
if issubclass(model_field.__class__, models.TextField):
|
|
kwargs['widget'] = widgets.Textarea
|
|
|
|
if model_field.verbose_name is not None:
|
|
kwargs['label'] = model_field.verbose_name
|
|
|
|
if model_field.help_text is not None:
|
|
kwargs['help_text'] = model_field.help_text
|
|
|
|
# TODO: TypedChoiceField?
|
|
if model_field.flatchoices: # This ModelField contains choices
|
|
kwargs['choices'] = model_field.flatchoices
|
|
if model_field.null:
|
|
kwargs['empty'] = None
|
|
return ChoiceField(**kwargs)
|
|
|
|
# put this below the ChoiceField because min_value isn't a valid initializer
|
|
if issubclass(model_field.__class__, models.PositiveIntegerField) or\
|
|
issubclass(model_field.__class__, models.PositiveSmallIntegerField):
|
|
kwargs['min_value'] = 0
|
|
|
|
if model_field.null and \
|
|
issubclass(model_field.__class__, (models.CharField, models.TextField)):
|
|
kwargs['allow_none'] = True
|
|
|
|
attribute_dict = {
|
|
models.CharField: ['max_length'],
|
|
models.CommaSeparatedIntegerField: ['max_length'],
|
|
models.DecimalField: ['max_digits', 'decimal_places'],
|
|
models.EmailField: ['max_length'],
|
|
models.FileField: ['max_length'],
|
|
models.ImageField: ['max_length'],
|
|
models.SlugField: ['max_length'],
|
|
models.URLField: ['max_length'],
|
|
}
|
|
|
|
attributes = _get_class_mapping(attribute_dict, model_field)
|
|
if attributes:
|
|
for attribute in attributes:
|
|
kwargs.update({attribute: getattr(model_field, attribute)})
|
|
|
|
serializer_field_class = _get_class_mapping(
|
|
self.field_mapping, model_field)
|
|
|
|
if serializer_field_class:
|
|
return serializer_field_class(**kwargs)
|
|
return ModelField(model_field=model_field, **kwargs)
|
|
|
|
def get_validation_exclusions(self, instance=None):
|
|
"""
|
|
Return a list of field names to exclude from model validation.
|
|
"""
|
|
cls = self.opts.model
|
|
opts = cls._meta.concrete_model._meta
|
|
exclusions = [field.name for field in opts.fields + opts.many_to_many]
|
|
|
|
for field_name, field in self.fields.items():
|
|
field_name = field.source or field_name
|
|
if (
|
|
field_name in exclusions
|
|
and not field.read_only
|
|
and (field.required or hasattr(instance, field_name))
|
|
and not isinstance(field, Serializer)
|
|
):
|
|
exclusions.remove(field_name)
|
|
return exclusions
|
|
|
|
def full_clean(self, instance):
|
|
"""
|
|
Perform Django's full_clean, and populate the `errors` dictionary
|
|
if any validation errors occur.
|
|
|
|
Note that we don't perform this inside the `.restore_object()` method,
|
|
so that subclasses can override `.restore_object()`, and still get
|
|
the full_clean validation checking.
|
|
"""
|
|
try:
|
|
instance.full_clean(exclude=self.get_validation_exclusions(instance))
|
|
except ValidationError as err:
|
|
self._errors = err.message_dict
|
|
return None
|
|
return instance
|
|
|
|
def restore_object(self, attrs, instance=None):
|
|
"""
|
|
Restore the model instance.
|
|
"""
|
|
m2m_data = {}
|
|
related_data = {}
|
|
nested_forward_relations = {}
|
|
meta = self.opts.model._meta
|
|
|
|
# Reverse fk or one-to-one relations
|
|
for (obj, model) in meta.get_all_related_objects_with_model():
|
|
field_name = obj.get_accessor_name()
|
|
if field_name in attrs:
|
|
related_data[field_name] = attrs.pop(field_name)
|
|
|
|
# Reverse m2m relations
|
|
for (obj, model) in meta.get_all_related_m2m_objects_with_model():
|
|
field_name = obj.get_accessor_name()
|
|
if field_name in attrs:
|
|
m2m_data[field_name] = attrs.pop(field_name)
|
|
|
|
# Forward m2m relations
|
|
for field in meta.many_to_many + meta.virtual_fields:
|
|
if isinstance(field, GenericForeignKey):
|
|
continue
|
|
if field.name in attrs:
|
|
m2m_data[field.name] = attrs.pop(field.name)
|
|
|
|
# Nested forward relations - These need to be marked so we can save
|
|
# them before saving the parent model instance.
|
|
for field_name in attrs.keys():
|
|
if isinstance(self.fields.get(field_name, None), Serializer):
|
|
nested_forward_relations[field_name] = attrs[field_name]
|
|
|
|
# Create an empty instance of the model
|
|
if instance is None:
|
|
instance = self.opts.model()
|
|
|
|
for key, val in attrs.items():
|
|
try:
|
|
setattr(instance, key, val)
|
|
except ValueError:
|
|
self._errors[key] = [self.error_messages['required']]
|
|
|
|
# Any relations that cannot be set until we've
|
|
# saved the model get hidden away on these
|
|
# private attributes, so we can deal with them
|
|
# at the point of save.
|
|
instance._related_data = related_data
|
|
instance._m2m_data = m2m_data
|
|
instance._nested_forward_relations = nested_forward_relations
|
|
|
|
return instance
|
|
|
|
def from_native(self, data, files):
|
|
"""
|
|
Override the default method to also include model field validation.
|
|
"""
|
|
instance = super(ModelSerializer, self).from_native(data, files)
|
|
if not self._errors:
|
|
return self.full_clean(instance)
|
|
|
|
def save_object(self, obj, **kwargs):
|
|
"""
|
|
Save the deserialized object.
|
|
"""
|
|
if getattr(obj, '_nested_forward_relations', None):
|
|
# Nested relationships need to be saved before we can save the
|
|
# parent instance.
|
|
for field_name, sub_object in obj._nested_forward_relations.items():
|
|
if sub_object:
|
|
self.save_object(sub_object)
|
|
setattr(obj, field_name, sub_object)
|
|
|
|
obj.save(**kwargs)
|
|
|
|
if getattr(obj, '_m2m_data', None):
|
|
for accessor_name, object_list in obj._m2m_data.items():
|
|
setattr(obj, accessor_name, object_list)
|
|
del(obj._m2m_data)
|
|
|
|
if getattr(obj, '_related_data', None):
|
|
related_fields = dict([
|
|
(field.get_accessor_name(), field)
|
|
for field, model
|
|
in obj._meta.get_all_related_objects_with_model()
|
|
])
|
|
for accessor_name, related in obj._related_data.items():
|
|
if isinstance(related, RelationsList):
|
|
# Nested reverse fk relationship
|
|
for related_item in related:
|
|
fk_field = related_fields[accessor_name].field.name
|
|
setattr(related_item, fk_field, obj)
|
|
self.save_object(related_item)
|
|
|
|
# Delete any removed objects
|
|
if related._deleted:
|
|
[self.delete_object(item) for item in related._deleted]
|
|
|
|
elif isinstance(related, models.Model):
|
|
# Nested reverse one-one relationship
|
|
fk_field = obj._meta.get_field_by_name(accessor_name)[0].field.name
|
|
setattr(related, fk_field, obj)
|
|
self.save_object(related)
|
|
else:
|
|
# Reverse FK or reverse one-one
|
|
setattr(obj, accessor_name, related)
|
|
del(obj._related_data)
|
|
|
|
|
|
class HyperlinkedModelSerializerOptions(ModelSerializerOptions):
|
|
"""
|
|
Options for HyperlinkedModelSerializer
|
|
"""
|
|
def __init__(self, meta):
|
|
super(HyperlinkedModelSerializerOptions, self).__init__(meta)
|
|
self.view_name = getattr(meta, 'view_name', None)
|
|
self.lookup_field = getattr(meta, 'lookup_field', None)
|
|
self.url_field_name = getattr(meta, 'url_field_name', api_settings.URL_FIELD_NAME)
|
|
|
|
|
|
class HyperlinkedModelSerializer(ModelSerializer):
|
|
"""
|
|
A subclass of ModelSerializer that uses hyperlinked relationships,
|
|
instead of primary key relationships.
|
|
"""
|
|
_options_class = HyperlinkedModelSerializerOptions
|
|
_default_view_name = '%(model_name)s-detail'
|
|
_hyperlink_field_class = HyperlinkedRelatedField
|
|
_hyperlink_identify_field_class = HyperlinkedIdentityField
|
|
|
|
def get_default_fields(self):
|
|
fields = super(HyperlinkedModelSerializer, self).get_default_fields()
|
|
|
|
if self.opts.view_name is None:
|
|
self.opts.view_name = self._get_default_view_name(self.opts.model)
|
|
|
|
if self.opts.url_field_name not in fields:
|
|
url_field = self._hyperlink_identify_field_class(
|
|
view_name=self.opts.view_name,
|
|
lookup_field=self.opts.lookup_field
|
|
)
|
|
ret = self._dict_class()
|
|
ret[self.opts.url_field_name] = url_field
|
|
ret.update(fields)
|
|
fields = ret
|
|
|
|
return fields
|
|
|
|
def get_pk_field(self, model_field):
|
|
if self.opts.fields and model_field.name in self.opts.fields:
|
|
return self.get_field(model_field)
|
|
|
|
def get_related_field(self, model_field, related_model, to_many):
|
|
"""
|
|
Creates a default instance of a flat relational field.
|
|
"""
|
|
# TODO: filter queryset using:
|
|
# .using(db).complex_filter(self.rel.limit_choices_to)
|
|
kwargs = {
|
|
'queryset': related_model._default_manager,
|
|
'view_name': self._get_default_view_name(related_model),
|
|
'many': to_many
|
|
}
|
|
|
|
if model_field:
|
|
kwargs['required'] = not(model_field.null or model_field.blank)
|
|
if model_field.help_text is not None:
|
|
kwargs['help_text'] = model_field.help_text
|
|
if model_field.verbose_name is not None:
|
|
kwargs['label'] = model_field.verbose_name
|
|
|
|
if self.opts.lookup_field:
|
|
kwargs['lookup_field'] = self.opts.lookup_field
|
|
|
|
return self._hyperlink_field_class(**kwargs)
|
|
|
|
def get_identity(self, data):
|
|
"""
|
|
This hook is required for bulk update.
|
|
We need to override the default, to use the url as the identity.
|
|
"""
|
|
try:
|
|
return data.get(self.opts.url_field_name, None)
|
|
except AttributeError:
|
|
return None
|
|
|
|
def _get_default_view_name(self, model):
|
|
"""
|
|
Return the view name to use if 'view_name' is not specified in 'Meta'
|
|
"""
|
|
model_meta = model._meta
|
|
format_kwargs = {
|
|
'app_label': model_meta.app_label,
|
|
'model_name': model_meta.object_name.lower()
|
|
}
|
|
return self._default_view_name % format_kwargs
|