DRF end-point posting error for nested serialization - django

Question

Get method working in browse-able api end-point but when i try to post using my end-point through browser, it fires me this error: (My serializers are nested)
This is my serializers.py and it is Nested serilizers
from rest_framework import serializers
from . models import Author, Article, Category, Organization
class OrganizationSerializer(serializers.ModelSerializer):
class Meta:
model = Organization
fields = '__all__'
class AuthorSerializer(serializers.ModelSerializer):
organization = OrganizationSerializer()
class Meta:
model = Author
fields = '__all__'
class CategorySerializer(serializers.ModelSerializer):
class Meta:
model = Category
fields = '__all__'
class ArticleSerializer(serializers.ModelSerializer):
author = AuthorSerializer()
category = CategorySerializer()
class Meta:
model = Article
fields = '__all__'
and this is my models.py
from django.db import models
import uuid
class Organization(models.Model):
organization_name = models.CharField(max_length=50)
contact = models.CharField(max_length=12, unique=True)
def __str__(self):
return self.organization_name
class Author(models.Model):
name = models.CharField(max_length=40)
detail = models.TextField()
organization = models.ForeignKey(Organization, on_delete=models.DO_NOTHING)
def __str__(self):
return self.name
class Category(models.Model):
name = models.CharField(max_length=100)
def __str__(self):
return self.name
class Article(models.Model):
alias = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
author = models.ForeignKey(Author, on_delete=models.CASCADE, related_name='author')
title = models.CharField(max_length=200)
body = models.TextField()
category = models.ForeignKey(Category, on_delete=models.CASCADE)
and this is my views.py ( I am using APIView, not VIewset)
class ArticleDeleteUpdate(DestroyAPIView, UpdateAPIView):
queryset = Article.objects.all()
serializer_class = ArticleSerializer
lookup_field = 'alias'
and this is my urls.py
path('api/v1/article', views.ArticleListCreateGet.as_view(), name='article2'),
I worked 10 hours on it to fix the issue but i failed to fix it...
I am not getting whats wrong with this... this error ruined my sleep..
Can anyone help me please to fix this issue?

Answer 1

EDIT with the correct approach:
Sorry I just realized you are using ModelSerializers instead of Serializers.
You need to change from
class ArticleSerializer(serializers.ModelSerializer):
author = AuthorSerializer()
category = CategorySerializer()
class Meta:
model = Article
fields = '__all__'
to
class ArticleSerializer(serializers.ModelSerializer):
author = serializers.PrimaryKeyRelatedField()
category = serializers.PrimaryKeyRelatedField()
class Meta:
model = Article
fields = '__all__'
And check the documentation of PrimaryKeyRelatedField as it includes some different options that might be interesting for the design of your API
https://www.django-rest-framework.org/api-guide/relations/#primarykeyrelatedfield
Most likely you will need the read_only=True option so you don't need to override any method
Original answer with a bit of explanation:
You are getting the error because the POST is trying to create the nested objects but your serializer does not override the .create() method so the serializer does not know how to handle the nested relationships.
Take a look on https://www.django-rest-framework.org/api-guide/serializers/#writing-create-methods-for-nested-representations where you can get a grasp of what you need.