Allow generic date views to use related fields as date_field

[Lefteris Nikoltsios]

For example if we have some models like that:

class Blog(models.Model):
    title = models.TextField()
    pubdate = models.DateField()

class Article(models.Model):
    blog = models.ForeignKey(Blog)
    title = models.TextFIeld()
    pubdate = models.DateField()

the following view:

from django.views.generic.dates import MonthArchiveView

from .models import Article


class ArticleMonthArchiveView(MonthArchiveView):
    queryset = Article.objects.all()
    date_field = 'blog__pub_date'

will raise FieldDoesNotExist.

[Lefteris Nikoltsios]

​PR

[Jaap Roes]

I created issue #32846 which was marked as a duplicate. Looking at the patch provided for this ticket is seems that the most difficult part is the lack of an "official" way of resolving "field paths" like blog__pub_date to fields. Django admin provides some utility methods, but since it is a contrib app it cannot be used in other "core" Django code.

Is there a separate ticket that tracks this? (I couldn't find one.) The addition of a canonical way to resolve field paths could also be helpful for 3rd party apps, for example django-filter has it's own implementation: ​https://github.com/carltongibson/django-filter/blob/f507201addfb7f105e722573f3ced4b4a9870526/django_filters/utils.py#L143, and I'm certain there are others.