mirror of
https://github.com/encode/django-rest-framework.git
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1038 lines
36 KiB
Python
1038 lines
36 KiB
Python
"""
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Serializers and ModelSerializers are similar to Forms and ModelForms.
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Unlike forms, they are not constrained to dealing with HTML output, and
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form encoded input.
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Serialization in REST framework is a two-phase process:
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1. Serializers marshal between complex types like model instances, and
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python primatives.
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2. The process of marshalling between python primatives and request and
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response content is handled by parsers and renderers.
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"""
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from __future__ import unicode_literals
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import copy
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import datetime
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import types
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from decimal import Decimal
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from django.core.paginator import Page
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from django.db import models
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from django.forms import widgets
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from django.utils.datastructures import SortedDict
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from rest_framework.compat import get_concrete_model, six
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# Note: We do the following so that users of the framework can use this style:
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#
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# example_field = serializers.CharField(...)
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#
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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 *
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from rest_framework.fields import *
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def pretty_name(name):
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"""Converts 'first_name' to 'First name'"""
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if not name:
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return ''
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return name.replace('_', ' ').capitalize()
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class RelationsList(list):
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_deleted = []
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class NestedValidationError(ValidationError):
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"""
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The default ValidationError behavior is to stringify each item in the list
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if the messages are a list of error messages.
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In the case of nested serializers, where the parent has many children,
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then the child's `serializer.errors` will be a list of dicts. In the case
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of a single child, the `serializer.errors` will be a dict.
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We need to override the default behavior to get properly nested error dicts.
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"""
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def __init__(self, message):
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if isinstance(message, dict):
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self.messages = [message]
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else:
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self.messages = message
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class DictWithMetadata(dict):
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"""
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A dict-like object, that can have additional properties attached.
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"""
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def __getstate__(self):
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"""
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Used by pickle (e.g., caching).
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Overridden to remove the metadata from the dict, since it shouldn't be
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pickled and may in some instances be unpickleable.
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"""
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return dict(self)
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class SortedDictWithMetadata(SortedDict):
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"""
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A sorted dict-like object, that can have additional properties attached.
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"""
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def __getstate__(self):
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"""
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Used by pickle (e.g., caching).
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Overriden to remove the metadata from the dict, since it shouldn't be
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pickle and may in some instances be unpickleable.
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"""
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return SortedDict(self).__dict__
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def _is_protected_type(obj):
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"""
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True if the object is a native datatype that does not need to
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be serialized further.
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"""
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return isinstance(obj, (
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types.NoneType,
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int, long,
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datetime.datetime, datetime.date, datetime.time,
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float, Decimal,
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basestring)
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)
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def _get_declared_fields(bases, attrs):
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"""
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Create a list of serializer field instances from the passed in 'attrs',
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plus any fields on the base classes (in 'bases').
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Note that all fields from the base classes are used.
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"""
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fields = [(field_name, attrs.pop(field_name))
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for field_name, obj in list(six.iteritems(attrs))
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if isinstance(obj, Field)]
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fields.sort(key=lambda x: x[1].creation_counter)
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# If this class is subclassing another Serializer, add that Serializer's
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# fields. Note that we loop over the bases in *reverse*. This is necessary
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# in order to maintain the correct order of fields.
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for base in bases[::-1]:
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if hasattr(base, 'base_fields'):
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fields = list(base.base_fields.items()) + fields
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return SortedDict(fields)
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class SerializerMetaclass(type):
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def __new__(cls, name, bases, attrs):
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attrs['base_fields'] = _get_declared_fields(bases, attrs)
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return super(SerializerMetaclass, cls).__new__(cls, name, bases, attrs)
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class SerializerOptions(object):
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"""
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Meta class options for Serializer
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"""
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def __init__(self, meta):
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self.depth = getattr(meta, 'depth', 0)
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self.fields = getattr(meta, 'fields', ())
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self.exclude = getattr(meta, 'exclude', ())
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class BaseSerializer(WritableField):
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"""
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This is the Serializer implementation.
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We need to implement it as `BaseSerializer` due to metaclass magicks.
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"""
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class Meta(object):
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pass
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_options_class = SerializerOptions
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_dict_class = SortedDictWithMetadata
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def __init__(self, instance=None, data=None, files=None,
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context=None, partial=False, many=None,
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allow_add_remove=False, **kwargs):
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super(BaseSerializer, self).__init__(**kwargs)
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self.opts = self._options_class(self.Meta)
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self.parent = None
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self.root = None
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self.partial = partial
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self.many = many
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self.allow_add_remove = allow_add_remove
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self.context = context or {}
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self.init_data = data
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self.init_files = files
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self.object = instance
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self.fields = self.get_fields()
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self._data = None
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self._files = None
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self._errors = None
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if many and instance is not None and not hasattr(instance, '__iter__'):
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raise ValueError('instance should be a queryset or other iterable with many=True')
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if allow_add_remove and not many:
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raise ValueError('allow_add_remove should only be used for bulk updates, but you have not set many=True')
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#####
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# Methods to determine which fields to use when (de)serializing objects.
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def get_default_fields(self):
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"""
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Return the complete set of default fields for the object, as a dict.
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"""
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return {}
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def get_fields(self):
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"""
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Returns the complete set of fields for the object as a dict.
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This will be the set of any explicitly declared fields,
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plus the set of fields returned by get_default_fields().
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"""
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ret = SortedDict()
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# Get the explicitly declared fields
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base_fields = copy.deepcopy(self.base_fields)
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for key, field in base_fields.items():
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ret[key] = field
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# Add in the default fields
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default_fields = self.get_default_fields()
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for key, val in default_fields.items():
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if key not in ret:
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ret[key] = val
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# If 'fields' is specified, use those fields, in that order.
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if self.opts.fields:
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assert isinstance(self.opts.fields, (list, tuple)), '`fields` must be a list or tuple'
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new = SortedDict()
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for key in self.opts.fields:
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new[key] = ret[key]
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ret = new
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# Remove anything in 'exclude'
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if self.opts.exclude:
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assert isinstance(self.opts.exclude, (list, tuple)), '`exclude` must be a list or tuple'
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for key in self.opts.exclude:
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ret.pop(key, None)
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for key, field in ret.items():
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field.initialize(parent=self, field_name=key)
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return ret
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#####
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# Methods to convert or revert from objects <--> primitive representations.
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def get_field_key(self, field_name):
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"""
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Return the key that should be used for a given field.
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"""
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return field_name
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def restore_fields(self, data, files):
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"""
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Core of deserialization, together with `restore_object`.
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Converts a dictionary of data into a dictionary of deserialized fields.
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"""
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reverted_data = {}
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if data is not None and not isinstance(data, dict):
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self._errors['non_field_errors'] = ['Invalid data']
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return None
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for field_name, field in self.fields.items():
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field.initialize(parent=self, field_name=field_name)
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try:
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field.field_from_native(data, files, field_name, reverted_data)
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except ValidationError as err:
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self._errors[field_name] = list(err.messages)
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return reverted_data
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def perform_validation(self, attrs):
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"""
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Run `validate_<fieldname>()` and `validate()` methods on the serializer
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"""
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for field_name, field in self.fields.items():
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if field_name in self._errors:
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continue
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try:
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validate_method = getattr(self, 'validate_%s' % field_name, None)
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if validate_method:
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source = field.source or field_name
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attrs = validate_method(attrs, source)
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except ValidationError as err:
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self._errors[field_name] = self._errors.get(field_name, []) + list(err.messages)
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# If there are already errors, we don't run .validate() because
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# field-validation failed and thus `attrs` may not be complete.
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# which in turn can cause inconsistent validation errors.
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if not self._errors:
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try:
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attrs = self.validate(attrs)
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except ValidationError as err:
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if hasattr(err, 'message_dict'):
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for field_name, error_messages in err.message_dict.items():
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self._errors[field_name] = self._errors.get(field_name, []) + list(error_messages)
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elif hasattr(err, 'messages'):
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self._errors['non_field_errors'] = err.messages
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return attrs
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def validate(self, attrs):
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"""
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Stub method, to be overridden in Serializer subclasses
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"""
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return attrs
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def restore_object(self, attrs, instance=None):
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"""
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Deserialize a dictionary of attributes into an object instance.
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You should override this method to control how deserialized objects
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are instantiated.
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"""
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if instance is not None:
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instance.update(attrs)
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return instance
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return attrs
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def to_native(self, obj):
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"""
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Serialize objects -> primitives.
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"""
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ret = self._dict_class()
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ret.fields = self._dict_class()
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for field_name, field in self.fields.items():
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if field.read_only and obj is None:
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continue
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field.initialize(parent=self, field_name=field_name)
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key = self.get_field_key(field_name)
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value = field.field_to_native(obj, field_name)
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method = getattr(self, 'transform_%s' % field_name, None)
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if callable(method):
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value = method(obj, value)
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ret[key] = value
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ret.fields[key] = self.augment_field(field, field_name, key, value)
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return ret
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def from_native(self, data, files):
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"""
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Deserialize primitives -> objects.
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"""
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self._errors = {}
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if data is not None or files is not None:
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attrs = self.restore_fields(data, files)
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if attrs is not None:
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attrs = self.perform_validation(attrs)
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else:
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self._errors['non_field_errors'] = ['No input provided']
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if not self._errors:
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return self.restore_object(attrs, instance=getattr(self, 'object', None))
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def augment_field(self, field, field_name, key, value):
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# This horrible stuff is to manage serializers rendering to HTML
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field._errors = self._errors.get(key) if self._errors else None
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field._name = field_name
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field._value = self.init_data.get(key) if self._errors and self.init_data else value
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if not field.label:
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field.label = pretty_name(key)
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return field
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def field_to_native(self, obj, field_name):
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"""
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Override default so that the serializer can be used as a nested field
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across relationships.
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"""
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if self.source == '*':
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return self.to_native(obj)
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# Get the raw field value
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try:
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source = self.source or field_name
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value = obj
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for component in source.split('.'):
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if value is None:
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break
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value = get_component(value, component)
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except ObjectDoesNotExist:
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return None
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if is_simple_callable(getattr(value, 'all', None)):
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return [self.to_native(item) for item in value.all()]
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if value is None:
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return None
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if self.many is not None:
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many = self.many
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else:
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many = hasattr(value, '__iter__') and not isinstance(value, (Page, dict, six.text_type))
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if many:
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return [self.to_native(item) for item in value]
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return self.to_native(value)
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def field_from_native(self, data, files, field_name, into):
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"""
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Override default so that the serializer can be used as a writable
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nested field across relationships.
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"""
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if self.read_only:
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return
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try:
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value = data[field_name]
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except KeyError:
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if self.default is not None and not self.partial:
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# Note: partial updates shouldn't set defaults
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value = copy.deepcopy(self.default)
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else:
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if self.required:
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raise ValidationError(self.error_messages['required'])
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return
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# Set the serializer object if it exists
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obj = getattr(self.parent.object, field_name) if self.parent.object else None
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obj = obj.all() if is_simple_callable(getattr(obj, 'all', None)) else obj
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if self.source == '*':
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if value:
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into.update(value)
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else:
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if value in (None, ''):
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into[(self.source or field_name)] = None
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else:
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kwargs = {
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'instance': obj,
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'data': value,
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'context': self.context,
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'partial': self.partial,
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'many': self.many,
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'allow_add_remove': self.allow_add_remove
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}
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serializer = self.__class__(**kwargs)
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if serializer.is_valid():
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into[self.source or field_name] = serializer.object
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else:
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# Propagate errors up to our parent
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raise NestedValidationError(serializer.errors)
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def get_identity(self, data):
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"""
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This hook is required for bulk update.
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It is used to determine the canonical identity of a given object.
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Note that the data has not been validated at this point, so we need
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to make sure that we catch any cases of incorrect datatypes being
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passed to this method.
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"""
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try:
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return data.get('id', None)
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except AttributeError:
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return None
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@property
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def errors(self):
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"""
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Run deserialization and return error data,
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setting self.object if no errors occurred.
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"""
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if self._errors is None:
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data, files = self.init_data, self.init_files
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if self.many is not None:
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many = self.many
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else:
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many = hasattr(data, '__iter__') and not isinstance(data, (Page, dict, six.text_type))
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if many:
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warnings.warn('Implict list/queryset serialization is deprecated. '
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'Use the `many=True` flag when instantiating the serializer.',
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DeprecationWarning, stacklevel=3)
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if many:
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ret = RelationsList()
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errors = []
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update = self.object is not None
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if update:
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# If this is a bulk update we need to map all the objects
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# to a canonical identity so we can determine which
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# individual object is being updated for each item in the
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# incoming data
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objects = self.object
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identities = [self.get_identity(self.to_native(obj)) for obj in objects]
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identity_to_objects = dict(zip(identities, objects))
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if hasattr(data, '__iter__') and not isinstance(data, (dict, six.text_type)):
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for item in data:
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if update:
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# Determine which object we're updating
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identity = self.get_identity(item)
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self.object = identity_to_objects.pop(identity, None)
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if self.object is None and not self.allow_add_remove:
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ret.append(None)
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errors.append({'non_field_errors': ['Cannot create a new item, only existing items may be updated.']})
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continue
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ret.append(self.from_native(item, None))
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errors.append(self._errors)
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if update and self.allow_add_remove:
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ret._deleted = identity_to_objects.values()
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self._errors = any(errors) and errors or []
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else:
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self._errors = {'non_field_errors': ['Expected a list of items.']}
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else:
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ret = self.from_native(data, files)
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if not self._errors:
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self.object = ret
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return self._errors
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def is_valid(self):
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return not self.errors
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@property
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def data(self):
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"""
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Returns the serialized data on the serializer.
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"""
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if self._data is None:
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obj = self.object
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if self.many is not None:
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many = self.many
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else:
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many = hasattr(obj, '__iter__') and not isinstance(obj, (Page, dict))
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if many:
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warnings.warn('Implict list/queryset serialization is deprecated. '
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'Use the `many=True` flag when instantiating the serializer.',
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DeprecationWarning, stacklevel=2)
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if many:
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self._data = [self.to_native(item) for item in obj]
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else:
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self._data = self.to_native(obj)
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return self._data
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def save_object(self, obj, **kwargs):
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obj.save(**kwargs)
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def delete_object(self, obj):
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obj.delete()
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def save(self, **kwargs):
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"""
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Save the deserialized object and return it.
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"""
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# Clear cached _data, which may be invalidated by `save()`
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self._data = None
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if isinstance(self.object, list):
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[self.save_object(item, **kwargs) for item in self.object]
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if self.object._deleted:
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[self.delete_object(item) for item in self.object._deleted]
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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', ())
|
|
|
|
|
|
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.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 = get_concrete_model(cls)._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
|
|
|
|
field = self.get_pk_field(pk_field)
|
|
if field:
|
|
ret[pk_field.name] = 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 = 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 due to be deprecated. '
|
|
'Use `get_nested_field(model_field, related_model, '
|
|
'to_many) instead',
|
|
PendingDeprecationWarning
|
|
)
|
|
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 due to be deprecated. '
|
|
'Use `get_related_field(model_field, related_model, '
|
|
'to_many) instead',
|
|
PendingDeprecationWarning
|
|
)
|
|
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 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
|
|
|
|
# Add the `read_only` flag to any fields that have bee 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
|
|
|
|
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)
|
|
|
|
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
|
|
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
|
|
|
|
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):
|
|
"""
|
|
Return a list of field names to exclude from model validation.
|
|
"""
|
|
cls = self.opts.model
|
|
opts = get_concrete_model(cls)._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 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())
|
|
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.field.related_query_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.field.related_query_name()
|
|
if field_name in attrs:
|
|
m2m_data[field_name] = attrs.pop(field_name)
|
|
|
|
# Forward m2m relations
|
|
for field in meta.many_to_many:
|
|
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]
|
|
|
|
# Update an existing instance...
|
|
if instance is not None:
|
|
for key, val in attrs.items():
|
|
setattr(instance, key, val)
|
|
|
|
# ...or create a new instance
|
|
else:
|
|
instance = self.opts.model(**attrs)
|
|
|
|
# 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):
|
|
for accessor_name, related in obj._related_data.items():
|
|
if isinstance(related, RelationsList):
|
|
# Nested reverse fk relationship
|
|
for related_item in related:
|
|
fk_field = obj._meta.get_field_by_name(accessor_name)[0].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)
|
|
|
|
|
|
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 'url' 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['url'] = 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 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('url', 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
|