Rename response fields django rest framework serializer

Question

I'm calling a simple get API using djangorestframework. My Model is

class Category(models.Model):
    category_id = models.AutoField(primary_key=True)
    category_name = models.CharField("Category Name", max_length = 30)
    category_created_date = models.DateField(auto_now = True, auto_now_add=False)
    category_updated_date = models.DateField(auto_now = True, auto_now_add=False)

    def __str__(self):
        return self.category_name

serializer.py

class CategorySerializer(serializers.ModelSerializer) :
    class Meta:
        model = Category
        fields = ['category_id', 'category_name']

def category_list(request):
    if request.method == 'GET':
        categories = Category.objects.all()
        serializer = CategorySerializer(categories, many=True)
        return Response(serializer.data)

It's working fine when i hit request on the URL and returning following response.

[
    {
        "category_id": 1,
        "category_name": "ABC"
    }
]

i want to change the response field names as it's for my DB only and don't want to disclose in response. If i change the name in serializer class than it's giving no field match error.

Also i want to customise other params like above response in response object with message and status like below.

{
status : 200,
message : "Category List",
response : [
        {
            "id": 1,
            "name": "ABC"
        }
    ]
}

Need a proper guide and flow. Experts help.

Answer 1

You can override to_representation function in serializer.Check the following code you can update data dictionary as you want.

class CategorySerializer(serializers.ModelSerializer) :
    class Meta:
        model = Category
        fields = ['category_id', 'category_name']
    def to_representation(self, instance):
        data = super(CategorySerializer, self).to_representation(instance)
        result_data={"status" : 200,"message" : "Category List"}
        result_data["response"]=data
        return result_data

Answer 2

First of all using category_ in field names is redundant. Because you are already assigning this fields to Category model, and by doing this you are creating "namespace" for this fields.

class Category(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField("Category Name", max_length = 30)
    created_date = models.DateField(auto_now = True, auto_now_add=False)
    updated_date = models.DateField(auto_now = True, auto_now_add=False)

    def __str__(self):
        return self.name

Second In django id AutoField is created automatically why would you need set it explicitly?

And answering your question There is source parameter in serializer fields.

class CategorySerializer(serializers.ModelSerializer):
    renamed_id = serializers.IntegerField(source='category_id')
    renamed_name = serializers.CharField(source='category_name')

    class Meta:
        model = Category
        fields = ['renamed_id', 'renamed_name']

And than you can change your response manually

from rest_framework import status

def category_list(request):
    if request.method == 'GET':
        categories = Category.objects.all()
        serializer = CategorySerializer(categories, many=True)
        response = {
            'status': status.HTTP_200_OK,
            'message' : "Category List",
            'response' : serializer.data
        }
        return Response(response)

Answer 3

You can just wrap it up in json. This is the way you render the way you want:

from django.http import HttpResponse
import json

def category_list(request):
    if request.method == 'GET':
        categories = Category.objects.all()
        serializer = CategorySerializer(categories, many=True)
        response = {'code: 200, 'message': 'Category List', 'response': serializer.data}
        return HttpResponse(json.dumps(response), mimetype='application/json')

This is the way you can rename your fields:

class CategorySerializer(serializers.ModelSerializer):
    name = serializers.CharField(source='category_name')

    class Meta:
        model = Category
        fields = ['category_id', 'name']

This is the docs for serializing with different names.

Answer 4

In Django 2.1.1 if you are using a viewset, you can customize the other parts of your response by overriding the .list() action like this

from rest_framework import status
from django.http import HttpResponse
import json

class CategoryViewset(viewsets.ReadOnlyModelViewSet):
    categories = Category.objects.all()

    def list(self, request):
        if request.method == 'GET':
            serializer = CategorySerializer(self.categories, many=True)
            response = {
                'status': status.HTTP_200_OK,
                'message' : "Category List",
                'response' : serializer.data,
            }
            return HttpResponse(json.dumps(response), content_type='application/json')