Add relative current_url

Description

current_url returns the full URL:

>>> request.htmx.current_url
'https://www.pythonmorsel.com/some-page/

I’d like a way to access just the non-domain part of this URL (I’m using it for a ?next= login redirect).

>>> request.htmx.relative_current_url
'/some-page/

I imagine something like this might work.

    @cached_property
    def relative_current_url(self) -> str | None:
        url = self.current_url
        if url:
            urlunparse(urlparse(url)._r(scheme='', netloc=''))
        return url

[adamchainz]

Added in #287, as current_url_abs_path.

I did and a bit of research to check naming, and was reminded that relative URL’s mean “relative to a given base URL, like ./image.pngis relative to whichever URL. The right name is “absolute-path” as per [section 4.2 of this RFC](https://www.rfc-editor.org/rfc/rfc3986#page-26), which is also what Django (kinda) uses e.g. inModel.get_absolute_url(). So I picked the name with the _abs_path` suffix, which is kinda wordy but at least correct.

[treyhunner]

Yeah I think adding the helper is probably too niche/security sensitive to solve here. Calling Django’s redirect_to_login to generate a response that you then just use the URL from doesn’t sit right.

I do agree that the specific use case I showed is a hack that isn’t wise. That was the first case that came up and I haven’t yet refactored that code.

I just came across another case today though.

Something like this in a non-HTMX Django page:

{% url "users:login" %}?next={{ request.get_full_path }}

Doesn’t have an equivalent in django-htmx land without a custom template filter/tag.

{% url "users:login" %}?next={{ request.htmx.relative_current_url }}

(Django gets upset when it’s an absolute URL).

How exactly? redirect_to_login() doesn’t seem to mind. The later “allowed redirect” check should be done by the internal function url_has_allowed_host_and_scheme(), which checks for an allowed origin, so it should be fine with absolute URL’s on the same origin?

From my testing, passing an absolute URL to next= didn’t seem to work. Django seems to just ignore the next value entirely when it wasn’t a relative URL (as of Django 3.2 at least).

(P.S. you probably want to use urlsplit() instead of urlparse(), as I learned recently. Django could probably do with that as well…)

Ah I do. Thanks for noting that!