mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-11-26 19:43:59 +03:00
1144 lines
41 KiB
Python
1144 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.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.fields = self.get_fields()
|
|
|
|
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.
|
|
|
|
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', ())
|
|
|
|
|
|
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) and model_field.editable
|
|
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 and model_field.editable:
|
|
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'],
|
|
}
|
|
|
|
if model_field.__class__ in attribute_dict:
|
|
attributes = attribute_dict[model_field.__class__]
|
|
for attribute in attributes:
|
|
kwargs.update({attribute: getattr(model_field, attribute)})
|
|
|
|
try:
|
|
return self.field_mapping[model_field.__class__](**kwargs)
|
|
except KeyError:
|
|
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) and model_field.editable
|
|
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
|