Added serializers and fields

djangorestframework/fields.py

+import copy
+import datetime
+import inspect
+import warnings
+
+from django.core import validators
+from django.core.exceptions import ValidationError
+from django.conf import settings
+from django.db import DEFAULT_DB_ALIAS
+from django.db.models.related import RelatedObject
+from django.utils import timezone
+from django.utils.dateparse import parse_date, parse_datetime
+from django.utils.encoding import is_protected_type, smart_unicode
+from django.utils.translation import ugettext_lazy as _
+
+
+def is_simple_callable(obj):
+    """
+    True if the object is a callable that takes no arguments.
+    """
+    return (
+        (inspect.isfunction(obj) and not inspect.getargspec(obj)[0]) or
+        (inspect.ismethod(obj) and len(inspect.getargspec(obj)[0]) <= 1)
+    )
+
+
+class Field(object):
+    creation_counter = 0
+    default_validators = []
+    default_error_messages = {
+        'required': _('This field is required.'),
+        'invalid': _('Invalid value.'),
+    }
+    empty = ''
+
+    def __init__(self, source=None, readonly=False, required=None,
+                 validators=[], error_messages=None):
+        self.parent = None
+
+        self.creation_counter = Field.creation_counter
+        Field.creation_counter += 1
+
+        self.source = source
+        self.readonly = readonly
+        self.required = not(readonly)
+
+        messages = {}
+        for c in reversed(self.__class__.__mro__):
+            messages.update(getattr(c, 'default_error_messages', {}))
+        messages.update(error_messages or {})
+        self.error_messages = messages
+
+        self.validators = self.default_validators + validators
+
+    def initialize(self, parent, model_field=None):
+        """
+        Called to set up a field prior to field_to_native or field_from_native.
+
+        parent - The parent serializer.
+        model_field - The model field this field corrosponds to, if one exists.
+        """
+        self.parent = parent
+        self.root = parent.root or parent
+        self.context = self.root.context
+        if model_field:
+            self.model_field = model_field
+
+    def validate(self, value):
+        pass
+        # if value in validators.EMPTY_VALUES and self.required:
+        #     raise ValidationError(self.error_messages['required'])
+
+    def run_validators(self, value):
+        if value in validators.EMPTY_VALUES:
+            return
+        errors = []
+        for v in self.validators:
+            try:
+                v(value)
+            except ValidationError as e:
+                if hasattr(e, 'code') and e.code in self.error_messages:
+                    message = self.error_messages[e.code]
+                    if e.params:
+                        message = message % e.params
+                    errors.append(message)
+                else:
+                    errors.extend(e.messages)
+        if errors:
+            raise ValidationError(errors)
+
+    def field_from_native(self, data, field_name, into):
+        """
+        Given a dictionary and a field name, updates the dictionary `into`,
+        with the field and it's deserialized value.
+        """
+        if self.readonly:
+            return
+
+        try:
+            native = data[field_name]
+        except KeyError:
+            return  # TODO Consider validation behaviour, 'required' opt etc...
+
+        value = self.from_native(native)
+        if self.source == '*':
+            if value:
+                into.update(value)
+        else:
+            self.validate(value)
+            self.run_validators(value)
+            into[self.source or field_name] = value
+
+    def from_native(self, value):
+        """
+        Reverts a simple representation back to the field's value.
+        """
+        if hasattr(self, 'model_field'):
+            try:
+                return self.model_field.rel.to._meta.get_field(self.model_field.rel.field_name).to_python(value)
+            except:
+                return self.model_field.to_python(value)
+        return value
+
+    def field_to_native(self, obj, field_name):
+        """
+        Given and object and a field name, returns the value that should be
+        serialized for that field.
+        """
+        if obj is None:
+            return self.empty
+
+        if self.source == '*':
+            return self.to_native(obj)
+
+        self.obj = obj  # Need to hang onto this in the case of model fields
+        if hasattr(self, 'model_field'):
+            return self.to_native(self.model_field._get_val_from_obj(obj))
+
+        return self.to_native(getattr(obj, self.source or field_name))
+
+    def to_native(self, value):
+        """
+        Converts the field's value into it's simple representation.
+        """
+        if is_simple_callable(value):
+            value = value()
+
+        if is_protected_type(value):
+            return value
+        elif hasattr(self, 'model_field'):
+            return self.model_field.value_to_string(self.obj)
+        return smart_unicode(value)
+
+    def attributes(self):
+        """
+        Returns a dictionary of attributes to be used when serializing to xml.
+        """
+        try:
+            return {
+                "type": self.model_field.get_internal_type()
+            }
+        except AttributeError:
+            return {}
+
+
+class RelatedField(Field):
+    """
+    A base class for model related fields or related managers.
+
+    Subclass this and override `convert` to define custom behaviour when
+    serializing related objects.
+    """
+
+    def field_to_native(self, obj, field_name):
+        obj = getattr(obj, field_name)
+        if obj.__class__.__name__ in ('RelatedManager', 'ManyRelatedManager'):
+            return [self.to_native(item) for item in obj.all()]
+        return self.to_native(obj)
+
+    def attributes(self):
+        try:
+            return {
+                "rel": self.model_field.rel.__class__.__name__,
+                "to": smart_unicode(self.model_field.rel.to._meta)
+            }
+        except AttributeError:
+            return {}
+
+
+class PrimaryKeyRelatedField(RelatedField):
+    """
+    Serializes a model related field or related manager to a pk value.
+    """
+
+    # Note the we use ModelRelatedField's implementation, as we want to get the
+    # raw database value directly, since that won't involve another
+    # database lookup.
+    #
+    # An alternative implementation would simply be this...
+    #
+    # class PrimaryKeyRelatedField(RelatedField):
+    #     def to_native(self, obj):
+    #         return obj.pk
+
+    def to_native(self, pk):
+        """
+        Simply returns the object's pk.  You can subclass this method to
+        provide different serialization behavior of the pk.
+        (For example returning a URL based on the model's pk.)
+        """
+        return pk
+
+    def field_to_native(self, obj, field_name):
+        try:
+            obj = obj.serializable_value(field_name)
+        except AttributeError:
+            field = obj._meta.get_field_by_name(field_name)[0]
+            obj = getattr(obj, field_name)
+            if obj.__class__.__name__ == 'RelatedManager':
+                return [self.to_native(item.pk) for item in obj.all()]
+            elif isinstance(field, RelatedObject):
+                return self.to_native(obj.pk)
+            raise
+        if obj.__class__.__name__ == 'ManyRelatedManager':
+            return [self.to_native(item.pk) for item in obj.all()]
+        return self.to_native(obj)
+
+    def field_from_native(self, data, field_name, into):
+        value = data.get(field_name)
+        if hasattr(value, '__iter__'):
+            into[field_name] = [self.from_native(item) for item in value]
+        else:
+            into[field_name + '_id'] = self.from_native(value)
+
+
+class NaturalKeyRelatedField(RelatedField):
+    """
+    Serializes a model related field or related manager to a natural key value.
+    """
+    is_natural_key = True  # XML renderer handles these differently
+
+    def to_native(self, obj):
+        if hasattr(obj, 'natural_key'):
+            return obj.natural_key()
+        return obj
+
+    def field_from_native(self, data, field_name, into):
+        value = data.get(field_name)
+        into[self.model_field.attname] = self.from_native(value)
+
+    def from_native(self, value):
+        # TODO: Support 'using' : db = options.pop('using', DEFAULT_DB_ALIAS)
+        manager = self.model_field.rel.to._default_manager
+        manager = manager.db_manager(DEFAULT_DB_ALIAS)
+        return manager.get_by_natural_key(*value).pk
+
+
+class BooleanField(Field):
+    default_error_messages = {
+        'invalid': _(u"'%s' value must be either True or False."),
+    }
+
+    def from_native(self, value):
+        if value in (True, False):
+            # if value is 1 or 0 than it's equal to True or False, but we want
+            # to return a true bool for semantic reasons.
+            return bool(value)
+        if value in ('t', 'True', '1'):
+            return True
+        if value in ('f', 'False', '0'):
+            return False
+        raise ValidationError(self.error_messages['invalid'] % value)
+
+
+class CharField(Field):
+    def __init__(self, max_length=None, min_length=None, *args, **kwargs):
+        self.max_length, self.min_length = max_length, min_length
+        super(CharField, self).__init__(*args, **kwargs)
+        if min_length is not None:
+            self.validators.append(validators.MinLengthValidator(min_length))
+        if max_length is not None:
+            self.validators.append(validators.MaxLengthValidator(max_length))
+
+    def from_native(self, value):
+        if isinstance(value, basestring) or value is None:
+            return value
+        return smart_unicode(value)
+
+
+class EmailField(CharField):
+    default_error_messages = {
+        'invalid': _('Enter a valid e-mail address.'),
+    }
+    default_validators = [validators.validate_email]
+
+    def from_native(self, value):
+        return super(EmailField, self).from_native(value).strip()
+
+    def __deepcopy__(self, memo):
+        result = copy.copy(self)
+        memo[id(self)] = result
+        #result.widget = copy.deepcopy(self.widget, memo)
+        result.validators = self.validators[:]
+        return result
+
+
+class DateField(Field):
+    default_error_messages = {
+        'invalid': _(u"'%s' value has an invalid date format. It must be "
+                     u"in YYYY-MM-DD format."),
+        'invalid_date': _(u"'%s' value has the correct format (YYYY-MM-DD) "
+                          u"but it is an invalid date."),
+    }
+    empty = None
+
+    def from_native(self, value):
+        if value is None:
+            return value
+        if isinstance(value, datetime.datetime):
+            if settings.USE_TZ and timezone.is_aware(value):
+                # Convert aware datetimes to the default time zone
+                # before casting them to dates (#17742).
+                default_timezone = timezone.get_default_timezone()
+                value = timezone.make_naive(value, default_timezone)
+            return value.date()
+        if isinstance(value, datetime.date):
+            return value
+
+        try:
+            parsed = parse_date(value)
+            if parsed is not None:
+                return parsed
+        except ValueError:
+            msg = self.error_messages['invalid_date'] % value
+            raise ValidationError(msg)
+
+        msg = self.error_messages['invalid'] % value
+        raise ValidationError(msg)
+
+
+class DateTimeField(Field):
+    default_error_messages = {
+        'invalid': _(u"'%s' value has an invalid format. It must be in "
+                     u"YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."),
+        'invalid_date': _(u"'%s' value has the correct format "
+                          u"(YYYY-MM-DD) but it is an invalid date."),
+        'invalid_datetime': _(u"'%s' value has the correct format "
+                              u"(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
+                              u"but it is an invalid date/time."),
+    }
+    empty = None
+
+    def from_native(self, value):
+        if value is None:
+            return value
+        if isinstance(value, datetime.datetime):
+            return value
+        if isinstance(value, datetime.date):
+            value = datetime.datetime(value.year, value.month, value.day)
+            if settings.USE_TZ:
+                # For backwards compatibility, interpret naive datetimes in
+                # local time. This won't work during DST change, but we can't
+                # do much about it, so we let the exceptions percolate up the
+                # call stack.
+                warnings.warn(u"DateTimeField received a naive datetime (%s)"
+                              u" while time zone support is active." % value,
+                              RuntimeWarning)
+                default_timezone = timezone.get_default_timezone()
+                value = timezone.make_aware(value, default_timezone)
+            return value
+
+        try:
+            parsed = parse_datetime(value)
+            if parsed is not None:
+                return parsed
+        except ValueError:
+            msg = self.error_messages['invalid_datetime'] % value
+            raise ValidationError(msg)
+
+        try:
+            parsed = parse_date(value)
+            if parsed is not None:
+                return datetime.datetime(parsed.year, parsed.month, parsed.day)
+        except ValueError:
+            msg = self.error_messages['invalid_date'] % value
+            raise ValidationError(msg)
+
+        msg = self.error_messages['invalid'] % value
+        raise ValidationError(msg)
+
+
+class IntegerField(Field):
+    default_error_messages = {
+        'invalid': _('Enter a whole number.'),
+        'max_value': _('Ensure this value is less than or equal to %(limit_value)s.'),
+        'min_value': _('Ensure this value is greater than or equal to %(limit_value)s.'),
+    }
+
+    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
+        self.max_value, self.min_value = max_value, min_value
+        super(IntegerField, self).__init__(*args, **kwargs)
+
+        if max_value is not None:
+            self.validators.append(validators.MaxValueValidator(max_value))
+        if min_value is not None:
+            self.validators.append(validators.MinValueValidator(min_value))
+
+    def from_native(self, value):
+        if value in validators.EMPTY_VALUES:
+            return None
+        try:
+            value = int(str(value))
+        except (ValueError, TypeError):
+            raise ValidationError(self.error_messages['invalid'])
+        return value
+
+
+class FloatField(Field):
+    default_error_messages = {
+        'invalid': _("'%s' value must be a float."),
+    }
+
+    def from_native(self, value):
+        if value is None:
+            return value
+        try:
+            return float(value)
+        except (TypeError, ValueError):
+            msg = self.error_messages['invalid'] % value
+            raise ValidationError(msg)
+
+# field_mapping = {
+#     models.AutoField: IntegerField,
+#     models.BooleanField: BooleanField,
+#     models.CharField: CharField,
+#     models.DateTimeField: DateTimeField,
+#     models.DateField: DateField,
+#     models.BigIntegerField: IntegerField,
+#     models.IntegerField: IntegerField,
+#     models.PositiveIntegerField: IntegerField,
+#     models.FloatField: FloatField
+# }
+
+
+# def modelfield_to_serializerfield(field):
+#     return field_mapping.get(type(field), Field)

djangorestframework/parsers.py

@@ -57,7 +57,7 @@ class BaseParser(object):
         """
         return media_type_matches(self.media_type, content_type)
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Given a *stream* to read from, return the deserialized output.
         Should return a 2-tuple of (data, files).
@@ -72,7 +72,7 @@ class JSONParser(BaseParser):
 
     media_type = 'application/json'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 
@@ -92,7 +92,7 @@ class YAMLParser(BaseParser):
 
     media_type = 'application/yaml'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 
@@ -112,7 +112,7 @@ class PlainTextParser(BaseParser):
 
     media_type = 'text/plain'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 
@@ -129,7 +129,7 @@ class FormParser(BaseParser):
 
     media_type = 'application/x-www-form-urlencoded'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 
@@ -147,13 +147,15 @@ class MultiPartParser(BaseParser):
 
     media_type = 'multipart/form-data'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 
         `data` will be a :class:`QueryDict` containing all the form parameters.
         `files` will be a :class:`QueryDict` containing all the form files.
         """
+        meta = opts['meta']
+        upload_handlers = opts['upload_handlers']
         try:
             parser = DjangoMultiPartParser(meta, stream, upload_handlers)
             return parser.parse()
@@ -168,7 +170,7 @@ class XMLParser(BaseParser):
 
     media_type = 'application/xml'
 
-    def parse(self, stream, meta, upload_handlers):
+    def parse(self, stream, **opts):
         """
         Returns a 2-tuple of `(data, files)`.
 

djangorestframework/request.py

@@ -214,7 +214,8 @@ class Request(object):
 
         for parser in self.get_parsers():
             if parser.can_handle_request(self.content_type):
-                return parser.parse(self.stream, self.META, self.upload_handlers)
+                return parser.parse(self.stream, meta=self.META,
+                                    upload_handlers=self.upload_handlers)
 
         raise UnsupportedMediaType(self._content_type)
 

djangorestframework/serializers.py

+from decimal import Decimal
+from django.core.serializers.base import DeserializedObject
+from django.utils.datastructures import SortedDict
+import copy
+import datetime
+import types
+from djangorestframework.fields import *
+
+
+class DictWithMetadata(dict):
+    """
+    A dict-like object, that can have additional properties attached.
+    """
+    pass
+
+
+class SortedDictWithMetadata(SortedDict, DictWithMetadata):
+    """
+    A sorted dict-like object, that can have additional properties attached.
+    """
+    pass
+
+
+class RecursionOccured(BaseException):
+    pass
+
+
+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 attrs.items()
+              if isinstance(obj, Field)]
+    fields.sort(key=lambda x: x[1].creation_counter)
+
+    # If this class is subclassing another Serializer, add that Serializer's
+    # fields.  Note that we loop over the bases in *reverse*. This is necessary
+    # in order to the correct order of fields.
+    for base in bases[::-1]:
+        if hasattr(base, 'base_fields'):
+            fields = 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 ModelSerializer
+    """
+    def __init__(self, meta):
+        self.nested = getattr(meta, 'nested', False)
+        self.fields = getattr(meta, 'fields', ())
+        self.exclude = getattr(meta, 'exclude', ())
+
+
+class BaseSerializer(Field):
+    class Meta(object):
+        pass
+
+    _options_class = SerializerOptions
+    _dict_class = SortedDictWithMetadata  # Set to unsorted dict for backwards compatability with unsorted implementations.
+
+    def __init__(self, data=None, instance=None, context=None, **kwargs):
+        super(BaseSerializer, self).__init__(**kwargs)
+        self.fields = copy.deepcopy(self.base_fields)
+        self.opts = self._options_class(self.Meta)
+        self.parent = None
+        self.root = None
+
+        self.stack = []
+        self.context = context or {}
+
+        self.init_data = data
+        self.instance = instance
+
+        self._data = None
+        self._errors = None
+
+    #####
+    # Methods to determine which fields to use when (de)serializing objects.
+
+    def default_fields(self, serialize, obj=None, data=None, nested=False):
+        """
+        Return the complete set of default fields for the object, as a dict.
+        """
+        return {}
+
+    def get_fields(self, serialize, obj=None, data=None, nested=False):
+        """
+        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
+        for key, field in self.fields.items():
+            ret[key] = field
+            # Determine if the declared field corrosponds to a model field.
+            try:
+                if key == 'pk':
+                    model_field = obj._meta.pk
+                else:
+                    model_field = obj._meta.get_field_by_name(key)[0]
+            except:
+                model_field = None
+            # Set up the field
+            field.initialize(parent=self, model_field=model_field)
+
+        # Add in the default fields
+        fields = self.default_fields(serialize, obj, data, nested)
+        for key, val in fields.items():
+            if key not in ret:
+                ret[key] = val
+
+        # If 'fields' is specified, use those fields, in that order.
+        if self.opts.fields:
+            new = SortedDict()
+            for key in self.opts.fields:
+                new[key] = ret[key]
+            ret = new
+
+        # Remove anything in 'exclude'
+        if self.opts.exclude:
+            for key in self.opts.exclude:
+                ret.pop(key, None)
+
+        return ret
+
+    #####
+    # Field methods - used when the serializer class is itself used as a field.
+
+    def initialize(self, parent, model_field=None):
+        """
+        Same behaviour as usual Field, except that we need to keep track
+        of state so that we can deal with handling maximum depth and recursion.
+        """
+        super(BaseSerializer, self).initialize(parent, model_field)
+        self.stack = parent.stack[:]
+        if parent.opts.nested and not isinstance(parent.opts.nested, bool):
+            self.opts.nested = parent.opts.nested - 1
+        else:
+            self.opts.nested = parent.opts.nested
+
+    #####
+    # Methods to convert or revert from objects <--> primative representations.
+
+    def get_field_key(self, field_name):
+        """
+        Return the key that should be used for a given field.
+        """
+        return field_name
+
+    def convert_object(self, obj):
+        """
+        Core of serialization.
+        Convert an object into a dictionary of serialized field values.
+        """
+        if obj in self.stack and not self.source == '*':
+            raise RecursionOccured()
+        self.stack.append(obj)
+
+        ret = self._dict_class()
+        ret.fields = {}
+
+        fields = self.get_fields(serialize=True, obj=obj, nested=self.opts.nested)
+        for field_name, field in fields.items():
+            key = self.get_field_key(field_name)
+            try:
+                value = field.field_to_native(obj, field_name)
+            except RecursionOccured:
+                field = self.get_fields(serialize=True, obj=obj, nested=False)[field_name]
+                value = field.field_to_native(obj, field_name)
+            ret[key] = value
+            ret.fields[key] = field
+        return ret
+
+    def restore_fields(self, data):
+        """
+        Core of deserialization, together with `restore_object`.
+        Converts a dictionary of data into a dictionary of deserialized fields.
+        """
+        fields = self.get_fields(serialize=False, data=data, nested=self.opts.nested)
+        reverted_data = {}
+        for field_name, field in fields.items():
+            try:
+                field.field_from_native(data, field_name, reverted_data)
+            except ValidationError as err:
+                self._errors[field_name] = list(err.messages)
+
+        return reverted_data
+
+    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 -> primatives.
+        """
+        if isinstance(obj, dict):
+            return dict([(key, self.to_native(val))
+                         for (key, val) in obj.items()])
+        elif hasattr(obj, '__iter__'):
+            return (self.to_native(item) for item in obj)
+        return self.convert_object(obj)
+
+    def from_native(self, data):
+        """
+        Deserialize primatives -> objects.
+        """
+        if hasattr(data, '__iter__') and not isinstance(data, dict):
+            # TODO: error data when deserializing lists
+            return (self.from_native(item) for item in data)
+        self._errors = {}
+        attrs = self.restore_fields(data)
+        if not self._errors:
+            return self.restore_object(attrs, instance=getattr(self, 'instance', None))
+
+    @property
+    def errors(self):
+        """
+        Run deserialization and return error data,
+        setting self.object if no errors occured.
+        """
+        if self._errors is None:
+            obj = self.from_native(self.init_data)
+            if not self._errors:
+                self.object = obj
+        return self._errors
+
+    def is_valid(self):
+        return not self.errors
+
+    @property
+    def data(self):
+        if self._data is None:
+            self._data = self.to_native(self.instance)
+        return self._data
+
+
+class Serializer(BaseSerializer):
+    __metaclass__ = SerializerMetaclass
+
+
+class ModelSerializerOptions(SerializerOptions):
+    """
+    Meta class options for ModelSerializer
+    """
+    def __init__(self, meta):
+        super(ModelSerializerOptions, self).__init__(meta)
+        self.model = getattr(meta, 'model', None)
+
+
+class ModelSerializer(RelatedField, Serializer):
+    """
+    A serializer that deals with model instances and querysets.
+    """
+    _options_class = ModelSerializerOptions
+
+    def default_fields(self, serialize, obj=None, data=None, nested=False):
+        """
+        Return all the fields that should be serialized for the model.
+        """
+        if serialize:
+            cls = obj.__class__
+        else:
+            cls = self.opts.model
+
+        opts = cls._meta.concrete_model._meta
+        pk_field = opts.pk
+        while pk_field.rel:
+            pk_field = pk_field.rel.to._meta.pk
+        fields = [pk_field]
+        fields += [field for field in opts.fields if field.serialize]
+        fields += [field for field in opts.many_to_many if field.serialize]
+
+        ret = SortedDict()
+        for model_field in fields:
+            if model_field.rel and nested:
+                field = self.get_nested_field(model_field)
+            elif model_field.rel:
+                field = self.get_related_field(model_field)
+            else:
+                field = self.get_field(model_field)
+            field.initialize(parent=self, model_field=model_field)
+            ret[model_field.name] = field
+        return ret
+
+    def get_nested_field(self, model_field):
+        """
+        Creates a default instance of a nested relational field.
+        """
+        return ModelSerializer()
+
+    def get_related_field(self, model_field):
+        """
+        Creates a default instance of a flat relational field.
+        """
+        return PrimaryKeyRelatedField()
+
+    def get_field(self, model_field):
+        """
+        Creates a default instance of a basic field.
+        """
+        return Field()
+
+    def restore_object(self, attrs, instance=None):
+        """
+        Restore the model instance.
+        """
+        m2m_data = {}
+        for field in self.opts.model._meta.many_to_many:
+            if field.name in attrs:
+                m2m_data[field.name] = attrs.pop(field.name)
+        return DeserializedObject(self.opts.model(**attrs), m2m_data)

djangorestframework/tests/parsers.py

@@ -153,7 +153,7 @@ class TestFormParser(TestCase):
         parser = FormParser()
 
         stream = StringIO(self.string)
-        (data, files) = parser.parse(stream, {}, [])
+        (data, files) = parser.parse(stream)
 
         self.assertEqual(Form(data).is_valid(), True)
 
@@ -203,10 +203,10 @@ class TestXMLParser(TestCase):
 
     def test_parse(self):
         parser = XMLParser()
-        (data, files) = parser.parse(self._input, {}, [])
+        (data, files) = parser.parse(self._input)
         self.assertEqual(data, self._data)
 
     def test_complex_data_parse(self):
         parser = XMLParser()
-        (data, files) = parser.parse(self._complex_data_input, {}, [])
+        (data, files) = parser.parse(self._complex_data_input)
         self.assertEqual(data, self._complex_data)

djangorestframework/tests/renderers.py

@@ -380,7 +380,7 @@ class XMLRendererTestCase(TestCase):
         content = StringIO(renderer.render(self._complex_data, 'application/xml'))
 
         parser = XMLParser()
-        complex_data_out, dummy = parser.parse(content, {}, [])
+        complex_data_out, dummy = parser.parse(content)
         error_msg = "complex data differs!IN:\n %s \n\n OUT:\n %s" % (repr(self._complex_data), repr(complex_data_out))
         self.assertEqual(self._complex_data, complex_data_out, error_msg)