Parsing and validating query params from GET request

Using Django Forms & APIs
1

Hi I am trying to validate incoming query params for a basic GET request. The amount of query params will be large so I need to think of a nice way to validate each of the parameters. I am using DRF and in this case I do not use a django model. It is starting to get weird and I am sure others have solved this problem so if some kind soul can point me to a better solution please do. I am certain this problem can be handled in a Django way.
What I have so far is the code below and it is working but perhaps someone has done something similar. In this example I have a GET endpoint that can accept params “foo”, “bar”, “baz”. They also happen to be required. I also do not use these params to query a database, rather I use them to interact with another third party API.

class SimpleView(views.APIView):
    required_param_fields = ("foo", "bar", "baz")
    
    def get(self, request: Request, *args, **kwargs) -> Response:
        self.validate_param_fields(request)
        # do some stuff and then return response

    def validate_param_fields(self, request: Request):
        missing_params = [
            param
            for param in self.required_param_fields
            if param not in request.query_params
        ]
        if missing_params:
            return Response(
                {
                    "error": f"Missing required query params: {', '.join(missing_params)}"
                },
                status=status.HTTP_400_BAD_REQUEST,
            )
        for param in self.required_param_fields:
            validator = getattr(self, f"validate_{param}")
            validator(request.query_params[param])

    def validate_foo(self, value):
        # validation logic here, raise ValidationError is something is wrong

    def validate_bar(self, value):
        # validation logic here, raise ValidationError is something is wrong

    def validate_baz(self, value):
        # validation logic here, raise ValidationError is something is wrong
2

Serializers can validate query parameters as well.

The difference is that you instance it using request.query_params instead of the request.data:

srlzr = SomeSerializer(data=request.query_params)
srlzr.is_valid(raise_exception=True)
1 Like