Field level validation with request.user in Django rest framework - django

Question

I am setting up a Django REST application where peopple can review restaurants. So far I have those models:
class RestaurantId(models.Model):
maps_id = models.CharField(max_length=140, unique=True)
adress = models.CharField(max_length=240)
name = models.CharField(max_length=140)
class RestaurantReview(models.Model):
review_author = models.ForeignKey(settings.AUTH_USER_MODEL,
on_delete=models.CASCADE)
restaurant_id = models.ForeignKey(RestaurantId, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class StarterPics(models.Model):
restaurant_review_id = models.OneToOneField(RestaurantReview,
on_delete=models.CASCADE)
pics_author = models.ForeignKey(User, on_delete=models.CASCADE)
restaurant_id = models.ForeignKey(RestaurantId, on_delete=models.CASCADE)
name_1 = models.CharField(max_length=40)
picture_1 = models.ImageField()
My serializers:
class RestaurantIdSerializer(serializers.ModelSerializer):
class Meta:
model = RestaurantId
field = fields = '__all__'
class RestaurantReviewSerializer(serializers.ModelSerializer):
class Meta:
model = RestaurantReview
field = fields = '__all__'
class StarterPicsSerializer(serializers.ModelSerializer):
class Meta:
model = StarterPics
fields = '__all__'
def validate_restaurant_review_id(self, value)
if value.review_author != self.request.user:
raise serializers.ValidationError("User has not reviewed the restaurant")
return value
My views:
class RestaurantIdViewset(viewsets.ModelViewSet):
queryset = models.RestaurantId.objects.all()
serializer_class = serializers.RestaurantIdSerializer
class RestaurantReviewViewset(viewsets.ModelViewSet):
queryset = models.RestaurantReview.objects.all()
serializer_class = serializers.RestaurantReviewSerializer
permission_classes = [IsAuthenticatedOrReadOnly,IsAuthorOrReadOnly]
def perform_create(self, serializer):
serializer.save(review_author=self.request.user)
class StarterPicsViewset(viewsets.ModelViewSet):
queryset = models.StarterPics.objects.all()
serializer_class = serializers.StarterPicsSerializer
permission_classes = [IsAuthenticatedOrReadOnly]
I have set up permissions as well so only the review_author can update his reviews and pics_author can update his pictures.
My permissions:
class IsOwnReviewOrReadOnly(permissions.BasePermission):
def has_object_permission(self, request, view, obj):
if request.method in permissions.SAFE_METHODS:
return True
return obj.pics_author == request.user
class IsAuthorOrReadOnly(permissions.BasePermission):
def has_object_permission(self, request, view, obj):
if request.method in permissions.SAFE_METHODS:
return True
return obj.review_author == request.user
When running Django server I got a 'StarterPicsSerializer' object has no attribute 'request'
This validation is for user that have not written the review (review_author) can't POST pictures in StarterPics. So only the User that creates the review can post pictures on it.
I've tried another validation with no luck either:
def validate_restaurant_review_id(self, value):
if not RestaurantReview.objects.filter(restaurant_review_id=value,
review_author=self.request.user).exists():
raise serializers.ValidationError('Not your review')
return value

Answer 1

You could provide extra context to the serializer in addition to the object being serialized by passing a context argument when instantiating the serializer in your view.
serializer = RandomSerializer(instance, context={'request': request})
If you use Generic Views or ModelViewSet(inherited form GenericAPIView), then request is already available in your serializer self.context dict
class StarterPicsSerializer(serializers.ModelSerializer):
class Meta:
model = StarterPics
fields = '__all__'
def validate_restaurant_review_id(self, value):
print(self.context['request'])