Allow django.contrib.admin's ListFilter to render details tag collasped by default

[Christophe Henry]

Custom ListFilter in django admin can yield a lot of results, in which case, the page can be very long.

This could be solved by adding a details_collapsed = True attribute to the ListFilter class and render the <details> tag according to that attribute.

[Marcelo Galigniana]

​PR

[Mariusz Felisiak]

I don't think that removing open will make much of a difference as exactly the same HTML will be build (with all options).

[Marcelo Galigniana]

Here is the PR where we added the collapse filter arrows (to solve the long page problem): ​https://github.com/django/django/pull/15424

I wouldn't allow user edit ListFilter as, if I'm not wrong, we don't recommend it in ​https://docs.djangoproject.com/en/4.2/ref/contrib/admin/filters

And add an option in SimpleListFilter to collapse ALL filters by default would make sense?

[Mariusz Felisiak]

Replying to Marcelo Galigniana:

And add an option in SimpleListFilter to collapse ALL filters by default would make sense?

My point is that if you have ListFilter with a long list of options, you will probably use something other than the built-in ListFilter because collapsing options by default would not solve the long-rendering issue.

[Marcelo Galigniana]

Yes! I agree with you +1