Django Rest Framework and JSONField

Given a Django model with a JSONField, what is the correct way of serializing and deserializing it using Django Rest Framework?

I've already tried crating a custom serializers.WritableField and overriding to_native and from_native:

from json_field.fields import JSONEncoder, JSONDecoder
from rest_framework import serializers

class JSONFieldSerializer(serializers.WritableField):
    def to_native(self, obj):
    return json.dumps(obj, cls = JSONEncoder)
	
    def from_native(self, data):
        return json.loads(data, cls = JSONDecoder)

But when I try to updating the model using partial=True, all the floats in the JSONField objects become strings.

If you're using Django Rest Framework >= 3.3, then the JSONField serializer is now included. This is now the correct way.

If you're using Django Rest Framework < 3.0, then see gzerone's answer.

If you're using DRF 3.0 - 3.2 AND you can't upgrade AND you don't need to serialize binary data, then follow these instructions.

First declare a field class:

from rest_framework import serializers

class JSONSerializerField(serializers.Field):
    """ Serializer for JSONField -- required to make field writable"""
    def to_internal_value(self, data):
        return data
    def to_representation(self, value):
        return value

And then add in the field into the model like

class MySerializer(serializers.ModelSerializer):
    json_data = JSONSerializerField()

And, if you do need to serialize binary data, you can always the copy official release code

In 2.4.x:

from rest_framework import serializers # get from https://gist.github.com/rouge8/5445149

class WritableJSONField(serializers.WritableField):
    def to_native(self, obj):
        return obj


class MyModelSerializer(serializers.HyperlinkedModelSerializer):
    my_json_field = WritableJSONField() # you need this.

serializers.WritableField is deprecated. This works:

from rest_framework import serializers
from website.models import Picture


class PictureSerializer(serializers.HyperlinkedModelSerializer):
    json = serializers.SerializerMethodField('clean_json')

    class Meta:
        model = Picture
        fields = ('id', 'json')
    
    def clean_json(self, obj):
        return obj.json

If and only if you know the first-level style of your JSON content (List or Dict), you can use DRF builtin DictField or ListField.

Ex:

class MyModelSerializer(serializers.HyperlinkedModelSerializer):
    my_json_field = serializers.DictField()

It works fine, with GET/PUT/PATCH/POST, including with nested contents.

Mark Chackerian script didn't work for me, I'd to force the json transform:

import json

class JSONSerializerField(serializers.Field):
    """ Serializer for JSONField -- required to make field writable"""

    def to_internal_value(self, data):
        json_data = {}
        try:
            json_data = json.loads(data)
        except ValueError, e:
            pass
        finally:
            return json_data
    def to_representation(self, value):
        return value

Works fine. Using DRF 3.15 and JSONFields in Django 1.8

For the record, this "just works" now if you are using PostgreSQL, and your model field is adjango.contrib.postgres.JSONField.

I'm on PostgreSQL 9.4, Django 1.9, and Django REST Framework 3.3.2.

I have previously used several of the other solutions listed here, but was able to delete that extra code.

Example Model:

class Account(models.Model):
    id = UUIDField(primary_key=True, default=uuid_nodash)
    data = JSONField(blank=True, default="")

Example Serializer:

class AccountSerializer(BaseSerializer):
    id = serializers.CharField()
    class Meta:
        model = Account
        fields = ('id','data')

Example View:

class AccountViewSet(
    viewsets.GenericViewSet,
    mixins.CreateModelMixin,      
    mixins.RetrieveModelMixin,
    mixins.ListModelMixin,
    mixins.UpdateModelMixin,
    mixins.DestroyModelMixin
): 
    model = Account
    queryset = Account.objects.all()
    serializer_class = AccountSerializer
    filter_fields = ['id', 'data']

Thanks by the help. This is the code i finally use for render it

class JSONSerializerField(serializers.Field):
    """Serializer for JSONField -- required to make field writable"""

    def to_representation(self, value):
        json_data = {}
        try:
            json_data = json.loads(value)
        except ValueError as e:
            raise e
        finally:
            return json_data

    def to_internal_value(self, data):
        return json.dumps(data)

class AnyModelSerializer(serializers.ModelSerializer):
    field = JSONSerializerField()

    class Meta:
        model = SomeModel
        fields = ('field',)

If you're using mysql (haven't tried with other databases), using both DRF's new JSONField and Mark Chackerian's suggested JSONSerializerField will save the json as a {u'foo': u'bar'} string. If you rather save it as {"foo": "bar"}, this works for me:

import json

class JSONField(serializers.Field):
    def to_representation(self, obj):
        return json.loads(obj)

    def to_internal_value(self, data):
        return json.dumps(data)

> DRF gives us inbuilt field 'JSONField' for binary data, but JSON > payload is verified only when you set 'binary' flag True then it convert into utf-8 and load the JSON payload, else it only > treat them as string(if invalid json is sent) or json and validate both without error even though you cretaed JSONField

class JSONSerializer(serializers.ModelSerializer):
    """
    serializer for JSON
    """
    payload = serializers.JSONField(binary=True)

To serialize a data from a request you can use the serializers.ModelSerializer

serializers.py

from rest_framwork import serializers
class FinalSerializer(serializers.ModelSerializer):
class Meta:
    model=Student
    fields='__all__'

views.py

import io
from yourappname.serializers import FinalSerializer #replace your app name
from rest_framework.parsers import JSONParser
from rest_framework.views import APIView
from rest_framework.parsers import JSONParser,MultiPartParser,FormParser
from rest_framework.response import Response


class DataList(APIView):


    parser_classes = (JSONParser,MultiPartParser,FormParser) #If you are using postman
    renderer_classes = (JSONRenderer,)
    #Serialize
    def get(self,request,format=None):
        all_data=Student.objects.all()
        serializer=FinalSerializer(all_data,many=True)
        return Response(serializer.data)#Will return serialized json data,makes sure you have data in your model
    #Deserialize
    #Not tried this function but it will work
    #from django documentation
    def djson(self,request,format=None):
        stream = io.BytesIO(json)
        data = JSONParser().parse(stream)
        serializer = FinalSerializer(data=data)
        serializer.is_valid()
        serializer.validated_data

If you want JSONField for mysql this is done in django-mysql and serializer was fixed some day ago [1], is not yet in any release.

[1] https://github.com/adamchainz/django-mysql/issues/353

#setting.py add:

    'django_mysql',

#models.py

from django_mysql.models import JSONField

class Something(models.Model):
(...)
    parameters = JSONField()