pythondjangovalidationdjango-rest-frameworkdjango-serializer

Validating POST parameters with serializers in Django

I'm trying to implement a simple validator for my POST parameters

My input looks like this:

{
  "gage_id": "01010000",
  "forcing_source":"my_source",
  "forcing_path":"my_path"
}

I have the following Serializer:

class SaveTab1Serializer(Serializer):
    gage_id = CharField(min_length=1, required=True),
    forcing_source = CharField(min_length=1, required=True),
    forcing_path = CharField(min_length=1, required=True),

And I use it like this:

@api_view(['POST'])
def save_tab1(request):
    body = json.loads(request.body)
    ser = SaveTab1Serializer(data=body)
    print('serializer', ser.is_valid())
    print('errors', ser.errors)

But no matter what I do with the data, it only shows as valid with no errors. Is there more code that I need to add to the serializer to do the validation?

Solution

  • You have an almost unnoticeable syntax error in your serializer. Serializer fields should be added "stand-alone", you don't need (and shouldn't use) trailing commas. For reasons I don't know, that messes with the serializer's ability to process the fields properly.

    Here's a standalone proof of concept:

    # test.py
import json
from rest_framework             import serializers
from rest_framework.decorators  import api_view, permission_classes
from rest_framework.permissions import AllowAny
from rest_framework.response    import Response


class SaveTab1Serializer(serializers.Serializer):
    gage_id = serializers.CharField(min_length=2, required=True)
    forcing_source = serializers.CharField(min_length=2, required=True)
    forcing_path = serializers.CharField(min_length=2, required=True)


@api_view(['POST'])
@permission_classes([AllowAny])
def save_tab1(request):
    body = json.loads(request.body)
    ser = SaveTab1Serializer(data=body)
    print('serializer', ser.is_valid())
    print('errors', ser.errors)
    return Response({ "data": body, "data_is_valid": ser.is_valid(), "data_errors": ser.errors })

# urls.py
path('test/', save_tab1, name='test'),

    Postman

    Postman

    By comparison, here's the same execution but with trailing commas:

    Postman