@action hyphenates url_name but not url_path

[blu14x]

just stumbled across this. the more I think about it, the stranger it seems to me.

@action(detail=True)
def doing_something(self, request)

creates an action with url_name "doing-something" and url_path "doing_something":

django-rest-framework/rest_framework/decorators.py

Lines 223 to 228 in b578eab

	def decorator(func):
	func.mapping = MethodMapper(func, methods)
	func.detail = detail
	func.url_path = url_path if url_path else func.__name__
	func.url_name = url_name if url_name else func.__name__.replace('_', '-')

It would make sense to me if the url_path were hyphenated, but it isn't. Instead, the url_name is hyphenated, which actually doesn't make sense to me. That wasn't actually mix them up, was it?

anyway, would be nice to have some settings for that

[FROWNINGdev]

It's intentional rather than a mix-up. The two attributes serve different consumers, and the docstring right above the lines you linked spells out both defaults: url_path is "the name of the method decorated", url_name is "the name of the method decorated with underscores replaced with dashes".

url_name never appears in a URL. The router splices it into the route name as '{basename}-{url_name}' (routers.py), next to the built-in {basename}-list and {basename}-detail. Hyphenating it keeps every reverse name in one style: thing-list, thing-detail, thing-doing-something.

url_path is the visible URL, and defaulting it to the method name is what every existing DRF API has been published with since @detail_route days. Flipping that default, or adding a global setting that flips it, would silently move every custom action URL in a project, which is probably why it has stayed as is.

If you want hyphenated paths across a project today, a thin wrapper does it without touching DRF:

from rest_framework.decorators import action as drf_action


def action(*, url_path=None, **kwargs):
    def decorator(func):
        path = url_path or func.__name__.replace("_", "-")
        return drf_action(url_path=path, **kwargs)(func)
    return decorator

Checked against DRF 3.18.1 with a SimpleRouter:

^things/(?P<pk>[^/.]+)/doing-something/$ -> thing-doing-something
^things/custom_path/$                    -> thing-other-thing   # explicit url_path is left alone

reverse("thing-doing-something", kwargs={"pk": 1}) gives /things/1/doing-something/, so reverse names don't change either.

[browniebroke]

It would make sense to me if the url_path were hyphenated, but it isn't

I agree, as I prefer hyphens in URL paths, but I would argue that it's a bit subjective.

Instead, the url_name is hyphenated, which actually doesn't make sense to me

I think this is to be consistent with how the default ViewSet actions are named: basename-detail, basename-list... But, yes, that's a different convention that what Django chose for the contrib admin app, for example. Again it's subjective IMO, different people prefer different approaches here.

would be nice to have some settings for that

There is already a hook to customise this in user-land:

@action(detail=True, url_path="doing-something")
def doing_something(self, request):
    ...

And as outlined above, you may implement a wrapper for making this convention consistent in your own project.

At the current stage of DRF's lifecycle, I'd say that it's now an established API to me, that we're unlikely to change. I don't see a lot of value in introducing a setting for it...