Django pagination: EmptyPage: That page contains no results

Question

When using Django CBV ListView with pagination:

class Proposals(ListView):
    model = Proposal
    ordering = "id"
    paginate_by = 10

In the browser, if I provide a page that is out of range, I get an error:

I would like to have a different behaviour: to fallback to the last existing page if the provided page is out of range.

I dug into Django source code paginator.py file and was surprised to find some code that does exactly this:

So using paginator.get_page(page) (and not paginator.page(page)) would be the way to go. However, ListView does not use it as you can see here:

What is the best way to deal with this?

Thanks.

We would need to see your source code to try to help. – Jarvis Aug 05 '22 at 18:45 — Jarvis, Aug 05 '22 at 18:45
@Jarvis I added my CBV but not sure how it could help. – David Dahan Aug 05 '22 at 18:52 — David Dahan, Aug 05 '22 at 18:52

score 0 · Answer 1 · answered Aug 05 '22 at 20:41

The only solution I found is by overriding the paginate_queryset method. However I don't like it as I'm forced to rewrite the whole logic while I just want to change a single line.

Open to any better suggestion.

class PermissivePaginationListView(ListView):
    def paginate_queryset(self, queryset, page_size):
        """
        This is an exact copy of the original method, jut changing `page` to `get_page` method to prevent errors with out of range pages.
        This is useful with HTMX, when the last row of the table is deleted, as the current page in URL is not valid anymore because there is no result in it.
        """
        paginator = self.get_paginator(
            queryset,
            page_size,
            orphans=self.get_paginate_orphans(),
            allow_empty_first_page=self.get_allow_empty(),
        )
        page_kwarg = self.page_kwarg
        page = self.kwargs.get(page_kwarg) or self.request.GET.get(page_kwarg) or 1
        try:
            page_number = int(page)
        except ValueError:
            if page == "last":
                page_number = paginator.num_pages
            else:
                raise Http404(_("Page is not “last”, nor can it be converted to an int."))
        try:
            page = paginator.get_page(page_number)
            return (paginator, page, page.object_list, page.has_other_pages())
        except InvalidPage as e:
            raise Http404(
                _("Invalid page (%(page_number)s): %(message)s")
                % {"page_number": page_number, "message": str(e)}
            )

This is odd… `get_page()` should handle that for you according to the documentation. I’ll have to dig into the CBV ListView code, this might warrant a change request to either the docs or the code. — Jarvis, Aug 06 '22 at 08:34
Yea, I think that should be documented with a best practice if you need the IMHO better behavior… or maybe a flag you can set… — Jarvis, Aug 07 '22 at 07:00

Django pagination: EmptyPage: That page contains no results

1 Answers1