class HyperlinkedModelSerializer

from rest_framework.serializers import HyperlinkedModelSerializer
    A type of `ModelSerializer` that uses hyperlinked relationships instead
    of primary key relationships. Specifically:

    * A 'url' field is included instead of the 'id' field.
    * Relationships to other instances are hyperlinks, instead of primary keys.
    

Ancestors (MRO)

  1. HyperlinkedModelSerializer
  2. ModelSerializer
  3. Serializer
  4. BaseSerializer
  5. Field

Attributes

  Defined in
_creation_counter = 2 Field
_declared_fields = OrderedDict() HyperlinkedModelSerializer
_declared_fields = OrderedDict() ModelSerializer
_declared_fields = OrderedDict() Serializer
_readable_fields = <django.utils.functional.cached_property object at 0x10c441990> Serializer
_writable_fields = <django.utils.functional.cached_property object at 0x10c441910> Serializer
context = <django.utils.functional.cached_property object at 0x10c40e950> Field
data = <property object at 0x10c444578> Serializer
data = <property object at 0x10c429ba8> BaseSerializer
default_empty_html = rest_framework.fields.empty Field
default_error_messages = {u'invalid': <django.utils.functional.__proxy__ object at 0x10c431890>} Serializer
default_error_messages = {u'null': <django.utils.functional.__proxy__ object at 0x10c40e8d0>, u'required': <django.utils.functional.__proxy__ object at 0x10c40e890>} Field
default_validators = [] Field
errors = <property object at 0x10c4445d0> Serializer
errors = <property object at 0x10c4443c0> BaseSerializer
fields = <property object at 0x10c444520> Serializer
initial = None Field
root = <django.utils.functional.cached_property object at 0x10c40e910> Field
serializer_choice_field = <class 'rest_framework.fields.ChoiceField'> ModelSerializer
serializer_field_mapping = {<class 'django.db.models.fields.UUIDField'>: <class 'rest_framework.fields.UUIDField'>, <class 'django.db.models.fields.GenericIPAddressField'>: <class 'rest_framework.fields.IPAddressField'>, <class 'django.db.models.fields.FilePathField'>: <class 'rest_framework.fields.FilePathField'>, <class 'django.db.models.fields.BooleanField'>: <class 'rest_framework.fields.BooleanField'>, <class 'django.db.models.fields.DateField'>: <class 'rest_framework.fields.DateField'>, <class 'django.db.models.fields.PositiveSmallIntegerField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.IPAddressField'>: <class 'rest_framework.fields.IPAddressField'>, <class 'django.db.models.fields.SmallIntegerField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.DecimalField'>: <class 'rest_framework.fields.DecimalField'>, <class 'django.db.models.fields.files.FileField'>: <class 'rest_framework.fields.FileField'>, <class 'django.db.models.fields.DateTimeField'>: <class 'rest_framework.fields.DateTimeField'>, <class 'django.db.models.fields.BigIntegerField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.EmailField'>: <class 'rest_framework.fields.EmailField'>, <class 'django.db.models.fields.IntegerField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.AutoField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.SlugField'>: <class 'rest_framework.fields.SlugField'>, <class 'django.db.models.fields.URLField'>: <class 'rest_framework.fields.URLField'>, <class 'django.db.models.fields.PositiveIntegerField'>: <class 'rest_framework.fields.IntegerField'>, <class 'django.db.models.fields.files.ImageField'>: <class 'rest_framework.fields.ImageField'>, <class 'django.db.models.fields.CommaSeparatedIntegerField'>: <class 'rest_framework.fields.CharField'>, <class 'django.db.models.fields.TextField'>: <class 'rest_framework.fields.CharField'>, <class 'django.db.models.fields.DurationField'>: <class 'rest_framework.fields.DurationField'>, <class 'django.db.models.fields.Field'>: <class 'rest_framework.fields.ModelField'>, <class 'django.db.models.fields.TimeField'>: <class 'rest_framework.fields.TimeField'>, <class 'django.db.models.fields.NullBooleanField'>: <class 'rest_framework.fields.NullBooleanField'>, <class 'django.db.models.fields.FloatField'>: <class 'rest_framework.fields.FloatField'>, <class 'django.db.models.fields.CharField'>: <class 'rest_framework.fields.CharField'>} ModelSerializer
serializer_related_field = <class 'rest_framework.relations.HyperlinkedRelatedField'> HyperlinkedModelSerializer
serializer_related_field = <class 'rest_framework.relations.PrimaryKeyRelatedField'> ModelSerializer
serializer_related_to_field = <class 'rest_framework.relations.SlugRelatedField'> ModelSerializer
serializer_url_field = <class 'rest_framework.relations.HyperlinkedIdentityField'> ModelSerializer
url_field_name = None ModelSerializer
validated_data = <property object at 0x10c444418> BaseSerializer
validators = <property object at 0x10c410890> Field

Methods used but not implemented in this class

  • default
Expand Collapse

Methods

def _get_model_fields(self, field_names, declared_fields, extra_kwargs): ModelSerializer

        Returns all the model fields that are being mapped to by fields
        on the serializer class.
        Returned as a dict of 'model field name' -> 'model field'.
        Used internally by `get_uniqueness_field_options`.
        
    def _get_model_fields(self, field_names, declared_fields, extra_kwargs):
        """
        Returns all the model fields that are being mapped to by fields
        on the serializer class.
        Returned as a dict of 'model field name' -> 'model field'.
        Used internally by `get_uniqueness_field_options`.
        """
        model = getattr(self.Meta, 'model')
        model_fields = {}

        for field_name in field_names:
            if field_name in declared_fields:
                # If the field is declared on the serializer
                field = declared_fields[field_name]
                source = field.source or field_name
            else:
                try:
                    source = extra_kwargs[field_name]['source']
                except KeyError:
                    source = field_name

            if '.' in source or source == '*':
                # Model fields will always have a simple source mapping,
                # they can't be nested attribute lookups.
                continue

            try:
                field = model._meta.get_field(source)
                if isinstance(field, DjangoModelField):
                    model_fields[source] = field
            except FieldDoesNotExist:
                pass

        return model_fields

def bind(self, field_name, parent): Field

        Initializes the field name and parent for the field instance.
        Called when a field is added to the parent serializer instance.
        
    def bind(self, field_name, parent):
        """
        Initializes the field name and parent for the field instance.
        Called when a field is added to the parent serializer instance.
        """

        # In order to enforce a consistent style, we error if a redundant
        # 'source' argument has been used. For example:
        # my_field = serializer.CharField(source='my_field')
        assert self.source != field_name, (
            "It is redundant to specify `source='%s'` on field '%s' in "
            "serializer '%s', because it is the same as the field name. "
            "Remove the `source` keyword argument." %
            (field_name, self.__class__.__name__, parent.__class__.__name__)
        )

        self.field_name = field_name
        self.parent = parent

        # `self.label` should default to being based on the field name.
        if self.label is None:
            self.label = field_name.replace('_', ' ').capitalize()

        # self.source should default to being the same as the field name.
        if self.source is None:
            self.source = field_name

        # self.source_attrs is a list of attributes that need to be looked up
        # when serializing the instance, or populating the validated data.
        if self.source == '*':
            self.source_attrs = []
        else:
            self.source_attrs = self.source.split('.')

def build_field(self, field_name, info, model_class, nested_depth): ModelSerializer

        Return a two tuple of (cls, kwargs) to build a serializer field with.
        
    def build_field(self, field_name, info, model_class, nested_depth):
        """
        Return a two tuple of (cls, kwargs) to build a serializer field with.
        """
        if field_name in info.fields_and_pk:
            model_field = info.fields_and_pk[field_name]
            return self.build_standard_field(field_name, model_field)

        elif field_name in info.relations:
            relation_info = info.relations[field_name]
            if not nested_depth:
                return self.build_relational_field(field_name, relation_info)
            else:
                return self.build_nested_field(field_name, relation_info, nested_depth)

        elif hasattr(model_class, field_name):
            return self.build_property_field(field_name, model_class)

        elif field_name == self.url_field_name:
            return self.build_url_field(field_name, model_class)

        return self.build_unknown_field(field_name, model_class)

def build_nested_field(self, field_name, relation_info, nested_depth):

HyperlinkedModelSerializer

        Create nested fields for forward and reverse relationships.
        
    def build_nested_field(self, field_name, relation_info, nested_depth):
        """
        Create nested fields for forward and reverse relationships.
        """
        class NestedSerializer(HyperlinkedModelSerializer):
            class Meta:
                model = relation_info.related_model
                depth = nested_depth - 1
                fields = '__all__'

        field_class = NestedSerializer
        field_kwargs = get_nested_relation_kwargs(relation_info)

        return field_class, field_kwargs

ModelSerializer

        Create nested fields for forward and reverse relationships.
        
    def build_nested_field(self, field_name, relation_info, nested_depth):
        """
        Create nested fields for forward and reverse relationships.
        """
        class NestedSerializer(ModelSerializer):
            class Meta:
                model = relation_info.related_model
                depth = nested_depth - 1
                fields = '__all__'

        field_class = NestedSerializer
        field_kwargs = get_nested_relation_kwargs(relation_info)

        return field_class, field_kwargs

def build_property_field(self, field_name, model_class): ModelSerializer

        Create a read only field for model methods and properties.
        
    def build_property_field(self, field_name, model_class):
        """
        Create a read only field for model methods and properties.
        """
        field_class = ReadOnlyField
        field_kwargs = {}

        return field_class, field_kwargs

def build_relational_field(self, field_name, relation_info): ModelSerializer

        Create fields for forward and reverse relationships.
        
    def build_relational_field(self, field_name, relation_info):
        """
        Create fields for forward and reverse relationships.
        """
        field_class = self.serializer_related_field
        field_kwargs = get_relation_kwargs(field_name, relation_info)

        to_field = field_kwargs.pop('to_field', None)
        if to_field and not relation_info.related_model._meta.get_field(to_field).primary_key:
            field_kwargs['slug_field'] = to_field
            field_class = self.serializer_related_to_field

        # `view_name` is only valid for hyperlinked relationships.
        if not issubclass(field_class, HyperlinkedRelatedField):
            field_kwargs.pop('view_name', None)

        return field_class, field_kwargs

def build_standard_field(self, field_name, model_field): ModelSerializer

        Create regular model fields.
        
    def build_standard_field(self, field_name, model_field):
        """
        Create regular model fields.
        """
        field_mapping = ClassLookupDict(self.serializer_field_mapping)

        field_class = field_mapping[model_field]
        field_kwargs = get_field_kwargs(field_name, model_field)

        if 'choices' in field_kwargs:
            # Fields with choices get coerced into `ChoiceField`
            # instead of using their regular typed field.
            field_class = self.serializer_choice_field
            # Some model fields may introduce kwargs that would not be valid
            # for the choice field. We need to strip these out.
            # Eg. models.DecimalField(max_digits=3, decimal_places=1, choices=DECIMAL_CHOICES)
            valid_kwargs = set((
                'read_only', 'write_only',
                'required', 'default', 'initial', 'source',
                'label', 'help_text', 'style',
                'error_messages', 'validators', 'allow_null', 'allow_blank',
                'choices'
            ))
            for key in list(field_kwargs.keys()):
                if key not in valid_kwargs:
                    field_kwargs.pop(key)

        if not issubclass(field_class, ModelField):
            # `model_field` is only valid for the fallback case of
            # `ModelField`, which is used when no other typed field
            # matched to the model field.
            field_kwargs.pop('model_field', None)

        if not issubclass(field_class, CharField) and not issubclass(field_class, ChoiceField):
            # `allow_blank` is only valid for textual fields.
            field_kwargs.pop('allow_blank', None)

        if postgres_fields and isinstance(model_field, postgres_fields.ArrayField):
            # Populate the `child` argument on `ListField` instances generated
            # for the PostgrSQL specfic `ArrayField`.
            child_model_field = model_field.base_field
            child_field_class, child_field_kwargs = self.build_standard_field(
                'child', child_model_field
            )
            field_kwargs['child'] = child_field_class(**child_field_kwargs)

        return field_class, field_kwargs

def build_unknown_field(self, field_name, model_class): ModelSerializer

        Raise an error on any unknown fields.
        
    def build_unknown_field(self, field_name, model_class):
        """
        Raise an error on any unknown fields.
        """
        raise ImproperlyConfigured(
            'Field name `%s` is not valid for model `%s`.' %
            (field_name, model_class.__name__)
        )

def build_url_field(self, field_name, model_class): ModelSerializer

        Create a field representing the object's own URL.
        
    def build_url_field(self, field_name, model_class):
        """
        Create a field representing the object's own URL.
        """
        field_class = self.serializer_url_field
        field_kwargs = get_url_kwargs(model_class)

        return field_class, field_kwargs

def create(self, validated_data):

ModelSerializer

        We have a bit of extra checking around this in order to provide
        descriptive messages when something goes wrong, but this method is
        essentially just:

            return ExampleModel.objects.create(**validated_data)

        If there are many to many fields present on the instance then they
        cannot be set until the model is instantiated, in which case the
        implementation is like so:

            example_relationship = validated_data.pop('example_relationship')
            instance = ExampleModel.objects.create(**validated_data)
            instance.example_relationship = example_relationship
            return instance

        The default implementation also does not handle nested relationships.
        If you want to support writable nested relationships you'll need
        to write an explicit `.create()` method.
        
    def create(self, validated_data):
        """
        We have a bit of extra checking around this in order to provide
        descriptive messages when something goes wrong, but this method is
        essentially just:

            return ExampleModel.objects.create(**validated_data)

        If there are many to many fields present on the instance then they
        cannot be set until the model is instantiated, in which case the
        implementation is like so:

            example_relationship = validated_data.pop('example_relationship')
            instance = ExampleModel.objects.create(**validated_data)
            instance.example_relationship = example_relationship
            return instance

        The default implementation also does not handle nested relationships.
        If you want to support writable nested relationships you'll need
        to write an explicit `.create()` method.
        """
        raise_errors_on_nested_writes('create', self, validated_data)

        ModelClass = self.Meta.model

        # Remove many-to-many relationships from validated_data.
        # They are not valid arguments to the default `.create()` method,
        # as they require that the instance has already been saved.
        info = model_meta.get_field_info(ModelClass)
        many_to_many = {}
        for field_name, relation_info in info.relations.items():
            if relation_info.to_many and (field_name in validated_data):
                many_to_many[field_name] = validated_data.pop(field_name)

        try:
            instance = ModelClass.objects.create(**validated_data)
        except TypeError:
            tb = traceback.format_exc()
            msg = (
                'Got a `TypeError` when calling `%s.objects.create()`. '
                'This may be because you have a writable field on the '
                'serializer class that is not a valid argument to '
                '`%s.objects.create()`. You may need to make the field '
                'read-only, or override the %s.create() method to handle '
                'this correctly.\nOriginal exception was:\n %s' %
                (
                    ModelClass.__name__,
                    ModelClass.__name__,
                    self.__class__.__name__,
                    tb
                )
            )
            raise TypeError(msg)

        # Save many-to-many relationships after the instance is created.
        if many_to_many:
            for field_name, value in many_to_many.items():
                setattr(instance, field_name, value)

        return instance

BaseSerializer

    def create(self, validated_data):
        raise NotImplementedError('`create()` must be implemented.')

def fail(self, key, **kwargs): Field

        A helper method that simply raises a validation error.
        
    def fail(self, key, **kwargs):
        """
        A helper method that simply raises a validation error.
        """
        try:
            msg = self.error_messages[key]
        except KeyError:
            class_name = self.__class__.__name__
            msg = MISSING_ERROR_MESSAGE.format(class_name=class_name, key=key)
            raise AssertionError(msg)
        message_string = msg.format(**kwargs)
        raise ValidationError(message_string)

def get_attribute(self, instance): Field

        Given the *outgoing* object instance, return the primitive value
        that should be used for this field.
        
    def get_attribute(self, instance):
        """
        Given the *outgoing* object instance, return the primitive value
        that should be used for this field.
        """
        try:
            return get_attribute(instance, self.source_attrs)
        except (KeyError, AttributeError) as exc:
            if not self.required and self.default is empty:
                raise SkipField()
            msg = (
                'Got {exc_type} when attempting to get a value for field '
                '`{field}` on serializer `{serializer}`.\nThe serializer '
                'field might be named incorrectly and not match '
                'any attribute or key on the `{instance}` instance.\n'
                'Original exception text was: {exc}.'.format(
                    exc_type=type(exc).__name__,
                    field=self.field_name,
                    serializer=self.parent.__class__.__name__,
                    instance=instance.__class__.__name__,
                    exc=exc
                )
            )
            raise type(exc)(msg)

def get_default(self): Field

        Return the default value to use when validating data if no input
        is provided for this field.

        If a default has not been set for this field then this will simply
        raise `SkipField`, indicating that no value should be set in the
        validated data for this field.
        
    def get_default(self):
        """
        Return the default value to use when validating data if no input
        is provided for this field.

        If a default has not been set for this field then this will simply
        raise `SkipField`, indicating that no value should be set in the
        validated data for this field.
        """
        if self.default is empty or getattr(self.root, 'partial', False):
            # No default, or this is a partial update.
            raise SkipField()
        if callable(self.default):
            if hasattr(self.default, 'set_context'):
                self.default.set_context(self)
            return self.default()
        return self.default

def get_default_field_names(self, declared_fields, model_info):

HyperlinkedModelSerializer

        Return the default list of field names that will be used if the
        `Meta.fields` option is not specified.
        
    def get_default_field_names(self, declared_fields, model_info):
        """
        Return the default list of field names that will be used if the
        `Meta.fields` option is not specified.
        """
        return (
            [self.url_field_name] +
            list(declared_fields.keys()) +
            list(model_info.fields.keys()) +
            list(model_info.forward_relations.keys())
        )

ModelSerializer

        Return the default list of field names that will be used if the
        `Meta.fields` option is not specified.
        
    def get_default_field_names(self, declared_fields, model_info):
        """
        Return the default list of field names that will be used if the
        `Meta.fields` option is not specified.
        """
        return (
            [model_info.pk.name] +
            list(declared_fields.keys()) +
            list(model_info.fields.keys()) +
            list(model_info.forward_relations.keys())
        )

def get_extra_kwargs(self): ModelSerializer

        Return a dictionary mapping field names to a dictionary of
        additional keyword arguments.
        
    def get_extra_kwargs(self):
        """
        Return a dictionary mapping field names to a dictionary of
        additional keyword arguments.
        """
        extra_kwargs = copy.deepcopy(getattr(self.Meta, 'extra_kwargs', {}))

        read_only_fields = getattr(self.Meta, 'read_only_fields', None)
        if read_only_fields is not None:
            if not isinstance(read_only_fields, (list, tuple)):
                raise TypeError(
                    'The `read_only_fields` option must be a list or tuple. '
                    'Got %s.' % type(read_only_fields).__name__
                )
            for field_name in read_only_fields:
                kwargs = extra_kwargs.get(field_name, {})
                kwargs['read_only'] = True
                extra_kwargs[field_name] = kwargs

        return extra_kwargs

def get_field_names(self, declared_fields, info): ModelSerializer

        Returns the list of all field names that should be created when
        instantiating this serializer class. This is based on the default
        set of fields, but also takes into account the `Meta.fields` or
        `Meta.exclude` options if they have been specified.
        
    def get_field_names(self, declared_fields, info):
        """
        Returns the list of all field names that should be created when
        instantiating this serializer class. This is based on the default
        set of fields, but also takes into account the `Meta.fields` or
        `Meta.exclude` options if they have been specified.
        """
        fields = getattr(self.Meta, 'fields', None)
        exclude = getattr(self.Meta, 'exclude', None)

        if fields and fields != ALL_FIELDS and not isinstance(fields, (list, tuple)):
            raise TypeError(
                'The `fields` option must be a list or tuple or "__all__". '
                'Got %s.' % type(fields).__name__
            )

        if exclude and not isinstance(exclude, (list, tuple)):
            raise TypeError(
                'The `exclude` option must be a list or tuple. Got %s.' %
                type(exclude).__name__
            )

        assert not (fields and exclude), (
            "Cannot set both 'fields' and 'exclude' options on "
            "serializer {serializer_class}.".format(
                serializer_class=self.__class__.__name__
            )
        )

        if fields is None and exclude is None:
            warnings.warn(
                "Creating a ModelSerializer without either the 'fields' "
                "attribute or the 'exclude' attribute is deprecated "
                "since 3.3.0. Add an explicit fields = '__all__' to the "
                "{serializer_class} serializer.".format(
                    serializer_class=self.__class__.__name__
                ),
                DeprecationWarning
            )

        if fields == ALL_FIELDS:
            fields = None

        if fields is not None:
            # Ensure that all declared fields have also been included in the
            # `Meta.fields` option.

            # Do not require any fields that are declared a parent class,
            # in order to allow serializer subclasses to only include
            # a subset of fields.
            required_field_names = set(declared_fields)
            for cls in self.__class__.__bases__:
                required_field_names -= set(getattr(cls, '_declared_fields', []))

            for field_name in required_field_names:
                assert field_name in fields, (
                    "The field '{field_name}' was declared on serializer "
                    "{serializer_class}, but has not been included in the "
                    "'fields' option.".format(
                        field_name=field_name,
                        serializer_class=self.__class__.__name__
                    )
                )
            return fields

        # Use the default set of field names if `Meta.fields` is not specified.
        fields = self.get_default_field_names(declared_fields, info)

        if exclude is not None:
            # If `Meta.exclude` is included, then remove those fields.
            for field_name in exclude:
                assert field_name in fields, (
                    "The field '{field_name}' was included on serializer "
                    "{serializer_class} in the 'exclude' option, but does "
                    "not match any model field.".format(
                        field_name=field_name,
                        serializer_class=self.__class__.__name__
                    )
                )
                fields.remove(field_name)

        return fields

def get_fields(self):

ModelSerializer

        Return the dict of field names -> field instances that should be
        used for `self.fields` when instantiating the serializer.
        
    def get_fields(self):
        """
        Return the dict of field names -> field instances that should be
        used for `self.fields` when instantiating the serializer.
        """
        if self.url_field_name is None:
            self.url_field_name = api_settings.URL_FIELD_NAME

        assert hasattr(self, 'Meta'), (
            'Class {serializer_class} missing "Meta" attribute'.format(
                serializer_class=self.__class__.__name__
            )
        )
        assert hasattr(self.Meta, 'model'), (
            'Class {serializer_class} missing "Meta.model" attribute'.format(
                serializer_class=self.__class__.__name__
            )
        )
        if model_meta.is_abstract_model(self.Meta.model):
            raise ValueError(
                'Cannot use ModelSerializer with Abstract Models.'
            )

        declared_fields = copy.deepcopy(self._declared_fields)
        model = getattr(self.Meta, 'model')
        depth = getattr(self.Meta, 'depth', 0)

        if depth is not None:
            assert depth >= 0, "'depth' may not be negative."
            assert depth <= 10, "'depth' may not be greater than 10."

        # Retrieve metadata about fields & relationships on the model class.
        info = model_meta.get_field_info(model)
        field_names = self.get_field_names(declared_fields, info)

        # Determine any extra field arguments and hidden fields that
        # should be included
        extra_kwargs = self.get_extra_kwargs()
        extra_kwargs, hidden_fields = self.get_uniqueness_extra_kwargs(
            field_names, declared_fields, extra_kwargs
        )

        # Determine the fields that should be included on the serializer.
        fields = OrderedDict()

        for field_name in field_names:
            # If the field is explicitly declared on the class then use that.
            if field_name in declared_fields:
                fields[field_name] = declared_fields[field_name]
                continue

            # Determine the serializer field class and keyword arguments.
            field_class, field_kwargs = self.build_field(
                field_name, info, model, depth
            )

            # Include any kwargs defined in `Meta.extra_kwargs`
            extra_field_kwargs = extra_kwargs.get(field_name, {})
            field_kwargs = self.include_extra_kwargs(
                field_kwargs, extra_field_kwargs
            )

            # Create the serializer field.
            fields[field_name] = field_class(**field_kwargs)

        # Add in any hidden fields.
        fields.update(hidden_fields)

        return fields

Serializer

        Returns a dictionary of {field_name: field_instance}.
        
    def get_fields(self):
        """
        Returns a dictionary of {field_name: field_instance}.
        """
        # Every new serializer is created with a clone of the field instances.
        # This allows users to dynamically modify the fields on a serializer
        # instance without affecting every other serializer class.
        return copy.deepcopy(self._declared_fields)

def get_initial(self):

Serializer

    def get_initial(self):
        if hasattr(self, 'initial_data'):
            return OrderedDict([
                (field_name, field.get_value(self.initial_data))
                for field_name, field in self.fields.items()
                if (field.get_value(self.initial_data) is not empty) and
                not field.read_only
            ])

        return OrderedDict([
            (field.field_name, field.get_initial())
            for field in self.fields.values()
            if not field.read_only
        ])

Field

        Return a value to use when the field is being returned as a primitive
        value, without any object instance.
        
    def get_initial(self):
        """
        Return a value to use when the field is being returned as a primitive
        value, without any object instance.
        """
        if callable(self.initial):
            return self.initial()
        return self.initial

def get_unique_for_date_validators(self): ModelSerializer

        Determine a default set of validators for the following constraints:

        * unique_for_date
        * unique_for_month
        * unique_for_year
        
    def get_unique_for_date_validators(self):
        """
        Determine a default set of validators for the following constraints:

        * unique_for_date
        * unique_for_month
        * unique_for_year
        """
        info = model_meta.get_field_info(self.Meta.model)
        default_manager = self.Meta.model._default_manager
        field_names = [field.source for field in self.fields.values()]

        validators = []

        for field_name, field in info.fields_and_pk.items():
            if field.unique_for_date and field_name in field_names:
                validator = UniqueForDateValidator(
                    queryset=default_manager,
                    field=field_name,
                    date_field=field.unique_for_date
                )
                validators.append(validator)

            if field.unique_for_month and field_name in field_names:
                validator = UniqueForMonthValidator(
                    queryset=default_manager,
                    field=field_name,
                    date_field=field.unique_for_month
                )
                validators.append(validator)

            if field.unique_for_year and field_name in field_names:
                validator = UniqueForYearValidator(
                    queryset=default_manager,
                    field=field_name,
                    date_field=field.unique_for_year
                )
                validators.append(validator)

        return validators

def get_unique_together_validators(self): ModelSerializer

        Determine a default set of validators for any unique_together constraints.
        
    def get_unique_together_validators(self):
        """
        Determine a default set of validators for any unique_together constraints.
        """
        model_class_inheritance_tree = (
            [self.Meta.model] +
            list(self.Meta.model._meta.parents.keys())
        )

        # The field names we're passing though here only include fields
        # which may map onto a model field. Any dotted field name lookups
        # cannot map to a field, and must be a traversal, so we're not
        # including those.
        field_names = {
            field.source for field in self._writable_fields
            if (field.source != '*') and ('.' not in field.source)
        }

        # Note that we make sure to check `unique_together` both on the
        # base model class, but also on any parent classes.
        validators = []
        for parent_class in model_class_inheritance_tree:
            for unique_together in parent_class._meta.unique_together:
                if field_names.issuperset(set(unique_together)):
                    validator = UniqueTogetherValidator(
                        queryset=parent_class._default_manager,
                        fields=unique_together
                    )
                    validators.append(validator)
        return validators

def get_uniqueness_extra_kwargs(self, field_names, declared_fields, extra_kwargs): ModelSerializer

        Return any additional field options that need to be included as a
        result of uniqueness constraints on the model. This is returned as
        a two-tuple of:

        ('dict of updated extra kwargs', 'mapping of hidden fields')
        
    def get_uniqueness_extra_kwargs(self, field_names, declared_fields, extra_kwargs):
        """
        Return any additional field options that need to be included as a
        result of uniqueness constraints on the model. This is returned as
        a two-tuple of:

        ('dict of updated extra kwargs', 'mapping of hidden fields')
        """
        if getattr(self.Meta, 'validators', None) is not None:
            return (extra_kwargs, {})

        model = getattr(self.Meta, 'model')
        model_fields = self._get_model_fields(
            field_names, declared_fields, extra_kwargs
        )

        # Determine if we need any additional `HiddenField` or extra keyword
        # arguments to deal with `unique_for` dates that are required to
        # be in the input data in order to validate it.
        unique_constraint_names = set()

        for model_field in model_fields.values():
            # Include each of the `unique_for_*` field names.
            unique_constraint_names |= {model_field.unique_for_date, model_field.unique_for_month,
                                        model_field.unique_for_year}

        unique_constraint_names -= {None}

        # Include each of the `unique_together` field names,
        # so long as all the field names are included on the serializer.
        for parent_class in [model] + list(model._meta.parents.keys()):
            for unique_together_list in parent_class._meta.unique_together:
                if set(field_names).issuperset(set(unique_together_list)):
                    unique_constraint_names |= set(unique_together_list)

        # Now we have all the field names that have uniqueness constraints
        # applied, we can add the extra 'required=...' or 'default=...'
        # arguments that are appropriate to these fields, or add a `HiddenField` for it.
        hidden_fields = {}
        uniqueness_extra_kwargs = {}

        for unique_constraint_name in unique_constraint_names:
            # Get the model field that is referred too.
            unique_constraint_field = model._meta.get_field(unique_constraint_name)

            if getattr(unique_constraint_field, 'auto_now_add', None):
                default = CreateOnlyDefault(timezone.now)
            elif getattr(unique_constraint_field, 'auto_now', None):
                default = timezone.now
            elif unique_constraint_field.has_default():
                default = unique_constraint_field.default
            else:
                default = empty

            if unique_constraint_name in model_fields:
                # The corresponding field is present in the serializer
                if default is empty:
                    uniqueness_extra_kwargs[unique_constraint_name] = {'required': True}
                else:
                    uniqueness_extra_kwargs[unique_constraint_name] = {'default': default}
            elif default is not empty:
                # The corresponding field is not present in the
                # serializer. We have a default to use for it, so
                # add in a hidden field that populates it.
                hidden_fields[unique_constraint_name] = HiddenField(default=default)

        # Update `extra_kwargs` with any new options.
        for key, value in uniqueness_extra_kwargs.items():
            if key in extra_kwargs:
                value.update(extra_kwargs[key])
            extra_kwargs[key] = value

        return extra_kwargs, hidden_fields

def get_validators(self):

ModelSerializer

        Determine the set of validators to use when instantiating serializer.
        
    def get_validators(self):
        """
        Determine the set of validators to use when instantiating serializer.
        """
        # If the validators have been declared explicitly then use that.
        validators = getattr(getattr(self, 'Meta', None), 'validators', None)
        if validators is not None:
            return validators[:]

        # Otherwise use the default set of validators.
        return (
            self.get_unique_together_validators() +
            self.get_unique_for_date_validators()
        )

Serializer

        Returns a list of validator callables.
        
    def get_validators(self):
        """
        Returns a list of validator callables.
        """
        # Used by the lazily-evaluated `validators` property.
        meta = getattr(self, 'Meta', None)
        validators = getattr(meta, 'validators', None)
        return validators[:] if validators else []

Field

    def get_validators(self):
        return self.default_validators[:]

def get_value(self, dictionary):

Serializer

    def get_value(self, dictionary):
        # We override the default field access in order to support
        # nested HTML forms.
        if html.is_html_input(dictionary):
            return html.parse_html_dict(dictionary, prefix=self.field_name) or empty
        return dictionary.get(self.field_name, empty)

Field

        Given the *incoming* primitive data, return the value for this field
        that should be validated and transformed to a native value.
        
    def get_value(self, dictionary):
        """
        Given the *incoming* primitive data, return the value for this field
        that should be validated and transformed to a native value.
        """
        if html.is_html_input(dictionary):
            # HTML forms will represent empty fields as '', and cannot
            # represent None or False values directly.
            if self.field_name not in dictionary:
                if getattr(self.root, 'partial', False):
                    return empty
                return self.default_empty_html
            ret = dictionary[self.field_name]
            if ret == '' and self.allow_null:
                # If the field is blank, and null is a valid value then
                # determine if we should use null instead.
                return '' if getattr(self, 'allow_blank', False) else None
            elif ret == '' and not self.required:
                # If the field is blank, and emptiness is valid then
                # determine if we should use emptiness instead.
                return '' if getattr(self, 'allow_blank', False) else empty
            return ret
        return dictionary.get(self.field_name, empty)

def include_extra_kwargs(self, kwargs, extra_kwargs): ModelSerializer

        Include any 'extra_kwargs' that have been included for this field,
        possibly removing any incompatible existing keyword arguments.
        
    def include_extra_kwargs(self, kwargs, extra_kwargs):
        """
        Include any 'extra_kwargs' that have been included for this field,
        possibly removing any incompatible existing keyword arguments.
        """
        if extra_kwargs.get('read_only', False):
            for attr in [
                'required', 'default', 'allow_blank', 'allow_null',
                'min_length', 'max_length', 'min_value', 'max_value',
                'validators', 'queryset'
            ]:
                kwargs.pop(attr, None)

        if extra_kwargs.get('default') and kwargs.get('required') is False:
            kwargs.pop('required')

        if extra_kwargs.get('read_only', kwargs.get('read_only', False)):
            extra_kwargs.pop('required', None)  # Read only fields should always omit the 'required' argument.

        kwargs.update(extra_kwargs)

        return kwargs

def is_valid(self, raise_exception=False): BaseSerializer

    def is_valid(self, raise_exception=False):
        assert not hasattr(self, 'restore_object'), (
            'Serializer `%s.%s` has old-style version 2 `.restore_object()` '
            'that is no longer compatible with REST framework 3. '
            'Use the new-style `.create()` and `.update()` methods instead.' %
            (self.__class__.__module__, self.__class__.__name__)
        )

        assert hasattr(self, 'initial_data'), (
            'Cannot call `.is_valid()` as no `data=` keyword argument was '
            'passed when instantiating the serializer instance.'
        )

        if not hasattr(self, '_validated_data'):
            try:
                self._validated_data = self.run_validation(self.initial_data)
            except ValidationError as exc:
                self._validated_data = {}
                self._errors = exc.detail
            else:
                self._errors = {}

        if self._errors and raise_exception:
            raise ValidationError(self.errors)

        return not bool(self._errors)

def many_init(cls, *args, **kwargs): BaseSerializer

        This method implements the creation of a `ListSerializer` parent
        class when `many=True` is used. You can customize it if you need to
        control which keyword arguments are passed to the parent, and
        which are passed to the child.

        Note that we're over-cautious in passing most arguments to both parent
        and child classes in order to try to cover the general case. If you're
        overriding this method you'll probably want something much simpler, eg:

        @classmethod
        def many_init(cls, *args, **kwargs):
            kwargs['child'] = cls()
            return CustomListSerializer(*args, **kwargs)
        
    @classmethod
    def many_init(cls, *args, **kwargs):
        """
        This method implements the creation of a `ListSerializer` parent
        class when `many=True` is used. You can customize it if you need to
        control which keyword arguments are passed to the parent, and
        which are passed to the child.

        Note that we're over-cautious in passing most arguments to both parent
        and child classes in order to try to cover the general case. If you're
        overriding this method you'll probably want something much simpler, eg:

        @classmethod
        def many_init(cls, *args, **kwargs):
            kwargs['child'] = cls()
            return CustomListSerializer(*args, **kwargs)
        """
        allow_empty = kwargs.pop('allow_empty', None)
        child_serializer = cls(*args, **kwargs)
        list_kwargs = {
            'child': child_serializer,
        }
        if allow_empty is not None:
            list_kwargs['allow_empty'] = allow_empty
        list_kwargs.update({
            key: value for key, value in kwargs.items()
            if key in LIST_SERIALIZER_KWARGS
        })
        meta = getattr(cls, 'Meta', None)
        list_serializer_class = getattr(meta, 'list_serializer_class', ListSerializer)
        return list_serializer_class(*args, **list_kwargs)

def run_validation(self, data=rest_framework.fields.empty):

Serializer

        We override the default `run_validation`, because the validation
        performed by validators and the `.validate()` method should
        be coerced into an error dictionary with a 'non_fields_error' key.
        
    def run_validation(self, data=empty):
        """
        We override the default `run_validation`, because the validation
        performed by validators and the `.validate()` method should
        be coerced into an error dictionary with a 'non_fields_error' key.
        """
        (is_empty_value, data) = self.validate_empty_values(data)
        if is_empty_value:
            return data

        value = self.to_internal_value(data)
        try:
            self.run_validators(value)
            value = self.validate(value)
            assert value is not None, '.validate() should return the validated data'
        except (ValidationError, DjangoValidationError) as exc:
            raise ValidationError(detail=get_validation_error_detail(exc))

        return value

Field

        Validate a simple representation and return the internal value.

        The provided data may be `empty` if no representation was included
        in the input.

        May raise `SkipField` if the field should not be included in the
        validated data.
        
    def run_validation(self, data=empty):
        """
        Validate a simple representation and return the internal value.

        The provided data may be `empty` if no representation was included
        in the input.

        May raise `SkipField` if the field should not be included in the
        validated data.
        """
        (is_empty_value, data) = self.validate_empty_values(data)
        if is_empty_value:
            return data
        value = self.to_internal_value(data)
        self.run_validators(value)
        return value

def run_validators(self, value): Field

        Test the given value against all the validators on the field,
        and either raise a `ValidationError` or simply return.
        
    def run_validators(self, value):
        """
        Test the given value against all the validators on the field,
        and either raise a `ValidationError` or simply return.
        """
        errors = []
        for validator in self.validators:
            if hasattr(validator, 'set_context'):
                validator.set_context(self)

            try:
                validator(value)
            except ValidationError as exc:
                # If the validation error contains a mapping of fields to
                # errors then simply raise it immediately rather than
                # attempting to accumulate a list of errors.
                if isinstance(exc.detail, dict):
                    raise
                errors.extend(exc.detail)
            except DjangoValidationError as exc:
                errors.extend(exc.messages)
        if errors:
            raise ValidationError(errors)

def save(self, **kwargs): BaseSerializer

    def save(self, **kwargs):
        assert not hasattr(self, 'save_object'), (
            'Serializer `%s.%s` has old-style version 2 `.save_object()` '
            'that is no longer compatible with REST framework 3. '
            'Use the new-style `.create()` and `.update()` methods instead.' %
            (self.__class__.__module__, self.__class__.__name__)
        )

        assert hasattr(self, '_errors'), (
            'You must call `.is_valid()` before calling `.save()`.'
        )

        assert not self.errors, (
            'You cannot call `.save()` on a serializer with invalid data.'
        )

        # Guard against incorrect use of `serializer.save(commit=False)`
        assert 'commit' not in kwargs, (
            "'commit' is not a valid keyword argument to the 'save()' method. "
            "If you need to access data before committing to the database then "
            "inspect 'serializer.validated_data' instead. "
            "You can also pass additional keyword arguments to 'save()' if you "
            "need to set extra attributes on the saved model instance. "
            "For example: 'serializer.save(owner=request.user)'.'"
        )

        assert not hasattr(self, '_data'), (
            "You cannot call `.save()` after accessing `serializer.data`."
            "If you need to access data before committing to the database then "
            "inspect 'serializer.validated_data' instead. "
        )

        validated_data = dict(
            list(self.validated_data.items()) +
            list(kwargs.items())
        )

        if self.instance is not None:
            self.instance = self.update(self.instance, validated_data)
            assert self.instance is not None, (
                '`update()` did not return an object instance.'
            )
        else:
            self.instance = self.create(validated_data)
            assert self.instance is not None, (
                '`create()` did not return an object instance.'
            )

        return self.instance

def to_internal_value(self, data):

Serializer

        Dict of native values <- Dict of primitive datatypes.
        
    def to_internal_value(self, data):
        """
        Dict of native values <- Dict of primitive datatypes.
        """
        if not isinstance(data, dict):
            message = self.error_messages['invalid'].format(
                datatype=type(data).__name__
            )
            raise ValidationError({
                api_settings.NON_FIELD_ERRORS_KEY: [message]
            })

        ret = OrderedDict()
        errors = OrderedDict()
        fields = self._writable_fields

        for field in fields:
            validate_method = getattr(self, 'validate_' + field.field_name, None)
            primitive_value = field.get_value(data)
            try:
                validated_value = field.run_validation(primitive_value)
                if validate_method is not None:
                    validated_value = validate_method(validated_value)
            except ValidationError as exc:
                errors[field.field_name] = exc.detail
            except DjangoValidationError as exc:
                errors[field.field_name] = list(exc.messages)
            except SkipField:
                pass
            else:
                set_value(ret, field.source_attrs, validated_value)

        if errors:
            raise ValidationError(errors)

        return ret

BaseSerializer

    def to_internal_value(self, data):
        raise NotImplementedError('`to_internal_value()` must be implemented.')

Field

        Transform the *incoming* primitive data into a native value.
        
    def to_internal_value(self, data):
        """
        Transform the *incoming* primitive data into a native value.
        """
        raise NotImplementedError(
            '{cls}.to_internal_value() must be implemented.'.format(
                cls=self.__class__.__name__
            )
        )

def to_representation(self, instance):

Serializer

        Object instance -> Dict of primitive datatypes.
        
    def to_representation(self, instance):
        """
        Object instance -> Dict of primitive datatypes.
        """
        ret = OrderedDict()
        fields = self._readable_fields

        for field in fields:
            try:
                attribute = field.get_attribute(instance)
            except SkipField:
                continue

            # We skip `to_representation` for `None` values so that fields do
            # not have to explicitly deal with that case.
            #
            # For related fields with `use_pk_only_optimization` we need to
            # resolve the pk value.
            check_for_none = attribute.pk if isinstance(attribute, PKOnlyObject) else attribute
            if check_for_none is None:
                ret[field.field_name] = None
            else:
                ret[field.field_name] = field.to_representation(attribute)

        return ret

BaseSerializer

    def to_representation(self, instance):
        raise NotImplementedError('`to_representation()` must be implemented.')

Field

        Transform the *outgoing* native value into primitive data.
        
    def to_representation(self, value):
        """
        Transform the *outgoing* native value into primitive data.
        """
        raise NotImplementedError(
            '{cls}.to_representation() must be implemented for field '
            '{field_name}. If you do not need to support write operations '
            'you probably want to subclass `ReadOnlyField` instead.'.format(
                cls=self.__class__.__name__,
                field_name=self.field_name,
            )
        )

def update(self, instance, validated_data):

ModelSerializer

    def update(self, instance, validated_data):
        raise_errors_on_nested_writes('update', self, validated_data)

        # Simply set each attribute on the instance, and then save it.
        # Note that unlike `.create()` we don't need to treat many-to-many
        # relationships as being a special case. During updates we already
        # have an instance pk for the relationships to be associated with.
        for attr, value in validated_data.items():
            setattr(instance, attr, value)
        instance.save()

        return instance

BaseSerializer

    def update(self, instance, validated_data):
        raise NotImplementedError('`update()` must be implemented.')

def validate(self, attrs): Serializer

    def validate(self, attrs):
        return attrs

def validate_empty_values(self, data): Field

        Validate empty values, and either:

        * Raise `ValidationError`, indicating invalid data.
        * Raise `SkipField`, indicating that the field should be ignored.
        * Return (True, data), indicating an empty value that should be
          returned without any further validation being applied.
        * Return (False, data), indicating a non-empty value, that should
          have validation applied as normal.
        
    def validate_empty_values(self, data):
        """
        Validate empty values, and either:

        * Raise `ValidationError`, indicating invalid data.
        * Raise `SkipField`, indicating that the field should be ignored.
        * Return (True, data), indicating an empty value that should be
          returned without any further validation being applied.
        * Return (False, data), indicating a non-empty value, that should
          have validation applied as normal.
        """
        if self.read_only:
            return (True, self.get_default())

        if data is empty:
            if getattr(self.root, 'partial', False):
                raise SkipField()
            if self.required:
                self.fail('required')
            return (True, self.get_default())

        if data is None:
            if not self.allow_null:
                self.fail('null')
            return (True, None)

        return (False, data)