django rest framework - POST request causes 400 status code - django

Question

I am trying to perform a POST request to create an article and I am getting this error Request failed with status code 400 Bad Request: /api/articles/create/.
An article needs 3 attributes to be created:
(1) title
(2) body
(3) author (the current user)
The router works fine since the POST request goes into the post method of the ArticleCreateView class. But I'm guessing that serializer.is_valid() is returning False for some reason.
Also print(request.data) returns {'title': 'hello', 'body': 'stuff'}
Another mystery about Django is, how does the serializer know if I want to get, create or update something? In all the examples I've seen, the serializer magically seems to know this.
class ArticleCreateView(CreateAPIView):
permission_classes = [IsAuthenticated]
def post(self, request):
serializer = ArticleSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.errors)
class ArticleSerializer(serializers.ModelSerializer):
class Meta:
model = Article
fields = '__all__'
def create(self, validated_data):
author = self.context['request'].user
title = validated_data.get('title')
body = validated_data.get('body')
return Article.objects.create(author=author, title=title, body=body)
class Article(models.Model):
author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
title = models.CharField(max_length=100)
body = models.TextField(max_length=100)
date_updated = models.DateTimeField(auto_now=True)
date_created = models.DateTimeField(auto_now_add=True)

Answer 1

According to your serializer, the validation process needs author details, which is not passing through POST payload.
So, make the author field in the serializer a not required field by adding required=False or use a ReadOnlyField() or specify read_only_fields in Meta class. Also pass context data as #nishant mentioned
# views.py
class ArticleCreateView(CreateAPIView):
permission_classes = [IsAuthenticated]
def post(self, request):
serializer = ArticleSerializer(data=request.data, context={"request": request}) # change here
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.errors)
# serializer.py
class ArticleSerializer(serializers.ModelSerializer):
class Meta:
model = Article
fields = '__all__'
read_only_fields = ('author',)
def create(self, validated_data):
author = self.context['request'].user
title = validated_data.get('title')
body = validated_data.get('body')
return Article.objects.create(author=author, title=title, body=body)

Answer 2

add this
serializer = ArticleSerializer(data=request.data, context={'request':request})