Sort groups by name in group index view

[cnk]

Fixes #11159

git bisect tells me that the sort on the group index view broke at commit 27aabc1 I would have thought that the new code would use the default_ordering in the IndexView but it clearly does not. Removing it and moving the ordering to the ViewSet restores ordering by name as the default sort order.

Please check the following:

• Do the tests still pass?¹
• Does the code comply with the style guide?
  • Run make lint from the Wagtail root.
• For Python changes: Have you added tests to cover the new/fixed behaviour?

Please describe additional details for testing this change.

Footnotes

1. Development Testing ↩

[squash-labs]

Manage this branch in Squash

Test this branch here: https://cnkissue-11159-9y2if.squash.io

[laymonage]

Looks good to me!

[laymonage]

I think we can move this to the test_default_ordering test directly, as it's not needed for the others

[laymonage]

Although thinking about why this happened in the first place, I'm wondering whether we should've made it so that these attributes fall back to the view's attribute by default instead of having its own default in the ModelViewSet (which is set to None).

This applies to other attributes e.g. list_per_page though, so I'm happy to accept this fix for now.

[laymonage]

I think this happens for Locale and Site too, so maybe I should rethink. Will get back to this in an hour!

[laymonage]

It seems we lucked out...

• Locale defines a Meta.ordering that's the same as the IndexView.default_ordering

  wagtail/wagtail/models/i18n.py

  Lines 51 to 54 in daa82eb

  	class Meta:
  	ordering = [
  	"language_code",
  	]

  wagtail/wagtail/locales/views.py

  Line 36 in daa82eb

  default_ordering = "language_code"

• Site calls order_by in the default manager's get_queryset(), not quite the same IndexView.default_ordering because it's case-insensitive, but I think that's OK (and the IndexView's ordering should probably be case-insensitive too anyway):

  wagtail/wagtail/models/sites.py

  Lines 64 to 66 in daa82eb

  	class SiteManager(models.Manager):
  	def get_queryset(self):
  	return super().get_queryset().order_by(Lower("hostname"))

  wagtail/wagtail/sites/views.py

  Line 15 in daa82eb

  default_ordering = "hostname"

With how close the release is, I'm inclined to leave them out of this PR. Will see if we can better handle this in 6.0.

[gasman]

Thanks @cnk and @laymonage! For 6.0 I think we should change the behaviour of ModelViewSet so that leaving ordering as None on the viewset causes it to be omitted from the get_index_view_kwargs, and do the same for any other attributes that might reasonably be left out of the viewset. (If we really want to be fancy we could define a custom 'undefined' value to distinguish between a developer leaving it unset on a ModelViewSet subclass, and explicitly setting it to None...)

[laymonage]

Thanks @gasman I agree, I think omitting it from the view kwargs would be the way to do it.

Cherry-picked to stable/5.2.x in 20fde5a.