Django REST Exceptions

Question

I currently have some code for a view based on the Django REST Framework. Ive been using a customer exception class, but ideally I want to use the inbuilt Django REST exceptions

Answer 1

The Django REST framework provides several built in exceptions, which are mostly subclasses of DRF's APIException.

You can raise exceptions in your view like you normally would in Python:

from rest_framework.exceptions import APIException

def my_view(request):
    raise APIException("There was a problem!")

You could also create your own custom exception by inheriting from APIException and setting status_code and default_detail. Some of the built in ones are: ParseError, AuthenticationFailed, NotAuthenticated, PermissionDenied, NotFound, NotAcceptable, ValidationError, etc.

These will then get converted to a Response by the REST Framework's exception handler. Each exception is associated with a status code that is added to the Response. By default the exception handler is set to the built in handler:

REST_FRAMEWORK = {
    'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler'
}

But you can set it to your own custom exception handler if you want to convert the exceptions yourself by changing this in your settings.py file:

REST_FRAMEWORK = {
    'EXCEPTION_HANDLER': 'my_project.my_app.utils.custom_exception_handler'
}

And then create the custom handler in that location:

from rest_framework.views import exception_handler

def custom_exception_handler(exc, context):
    # Call REST framework's default exception handler first,
    # to get the standard error response.
    response = exception_handler(exc, context)

    # Now add the HTTP status code to the response.
    if response is not None:
        response.data['status_code'] = response.status_code

    return response

Answer 2

You can use the build in DRF exception, just import and raise

from rest_framework.exceptions import
...
raise ParseError('I already have a status code!')