Managing the combination of NestedSimpleRouter.lookup and GenericViewset.lookup_field

[ghost]

Having a bit of trouble with this but it could just be me: is it possible to just use only one of these fields to declare a lookup string? Currently we have a non-primary-key field that's used for lookup, but we end up with some weirdness.

Leaving the default lookup_field on our GenericViewset subclass causes any of our "lookup" text to have _pk appended to it, such as foobar_pk

If we update the lookup_field we can get foobar_foobar, but trying to set lookup='' for the router leaves us with _foobar

I see this behavior comes from the very beginning of NestedMixin.__init__... Basically I just want the lookup field to only be foobar with nothing else, is there a way to do that or am I missing something?

[dsalisbury]

This is an issue that I've faced too -- and I found a sneaky solution for it. In NestedMixin.__init__, I saw that it calls self.nest_prefix = something_somethingelse, so what if we just make that a property that doesn't do anything when assigned, and returns an empty string when retrieved? Well that works, but the __init__ method later validates that self.nest_prefix matches an acceptable regex; by making that blindly return True it all works -- although the return value isn't actually checked.

class NestedMixin(rest_framework_nested.routers.NestedMixin):
    @property
    def nest_prefix(self):
        return ""

    @nest_prefix.setter
    def nest_prefix(self, value):
        pass

    def check_valid_name(self, value):
        return True

class NestedSimpleRouter(NestedMixin, SimpleRouter):
    pass

Before:

After:

[mdefeche]

Any chance this would be integrated in the lib somehow ? Extra param to disable prefix or simply a rule that disable prefix when lookup param is empty ?

[alanjds]

Any chance this would be integrated in the lib somehow ? Extra param to disable prefix or simply a rule that disable prefix when lookup param is empty ?

I cannot say that I truly understand the implications of this change. Yet is very possible to be accepted, given that new automated tests do pass along the existing ones in a PR 👍 .