CODEWITHSUNDEEP
pythondjangodjango-rest-framework
Sefa
Sefa

Reputation: 8992

Getting request object and extra parameters into custom decorator

I'm trying to write a custom decorator. I want to check if all the required parameters are sent with the request. I wrote something like this:

def get_parameters_required(parameters=None):
    missing_parameter = False
    if parameters is not None:
        for parameter in parameters:
            if request.GET.get(parameter) is None:
                missing_parameter = True

        if missing_parameter:
            return HttpResponse(status=400)

    def _get_parameters_required(view_func):
        def _decorator(request, *args, **kwargs):
            response = view_func(request, *args, **kwargs)
            return response
        return wraps(view_func)(_decorator)
    return _get_parameters_required

This doesn't work because i don't have the request object where i check the parameters. And where i have the request object, i don't have the parameters object.

Is there any built-in solution to this problem or how can i do write this decorator in the correct way?

Upvotes: 0

Views: 229

Answers (2)

hspandher
hspandher

Reputation: 16733

Why don't you ensure this in Serializer instead, after all that's what they are meant for?

If you are using function-based DRF views :-

def get_parameters_required(parameters=None):

    def _get_parameters_required(view_func):
        def _decorator(request, *args, **kwargs):
            missing_parameter = False
            if parameters is not None:
                for parameter in parameters:
                     if request.GET.get(parameter) is None:
                         missing_parameter = True

            if missing_parameter:
                return HttpResponse(status=400)

            response = view_func(request, *args, **kwargs)
            return response

        return wraps(view_func)(_decorator)
    return _get_parameters_required

In your current implementation, you need to check for parameter inside request method not outside.

Upvotes: 1

Daniel Roseman
Daniel Roseman

Reputation: 599490

The whole if statement should be inside the nested _decorator function, where you do have access to the request. You then only call view_func() if missing_parameter is False.

That said, as hspandher points out, this should be done by a Serializer.

Upvotes: 1

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