Document ModelAdmin.autocomplete_view() and AutocompleteJsonView (as customisation point).

[David W. Lloyd]

Reference: https://code.djangoproject.com/ticket/29010#comment:7

The new autocomplete view uses whatever ordering the ModelAdmin specifies, but most of the time you'd want autocomplete to be alphabetized so that typeahead suggestions make more sense and can be scanned visually. My particular use case is that I want certain admins to default to showing the most recently edited objects, but this sort order makes no sense for autocomplete views in lookups from related object change forms.

This seems like a common enough use case to warrant built-in decoupling of sort order for autocomplete view from ModelAdmin's standard "ordering" field.

Proposed improvement/feature would be an "autocomplete_ordering" field and corresponding "get_autocomplete_ordering" method which default to using the "ordering" but can be easily overridden, readily providing decoupling when needed.

[Carlton Gibson]

The use case here seems reasonable enough, but I'm (initially) skeptical about adding yet more API to ModelAdmin.

If that weren't an option, what would I do?

Well, I'd look to customise the autocomplete view:

    def autocomplete_view(self, request):
        return AutocompleteJsonView.as_view(model_admin=self)(request)

​source

Is there any reason I can't just override ​`AutocompleteJsonView.get_queryset()` to apply whatever ordering I need? (It doesn't look like there is...)

autocomplete_view()/AutocompleteJsonView/&co are not documented, so this ticket would amount to needing to add that (and maybe we make small adjustments to the ModelAPI) but (for me, initially) this would help to modularise the autocomplete options and be preferable to more top-level ModelAdmin options.

Thoughts?

[Johannes Maron]

Replying to Carlton Gibson:

The use case here seems reasonable enough, but I'm (initially) skeptical about adding yet more API to ModelAdmin.

That is a reasonable concern. The ModelAdmin is practically exploding. However that should not keep us from making changes, but only from blindly adding features.
Maybe there is a better way though as you suggested later.

If that weren't an option, what would I do?

Well, I'd look to customise the autocomplete view:

    def autocomplete_view(self, request):
        return AutocompleteJsonView.as_view(model_admin=self)(request)

​source

Is there any reason I can't just override ​`AutocompleteJsonView.get_queryset()` to apply whatever ordering I need? (It doesn't look like there is...)

autocomplete_view()/AutocompleteJsonView/&co are not documented, so this ticket would amount to needing to add that (and maybe we make small adjustments to the ModelAPI) but (for me, initially) this would help to modularise the autocomplete options and be preferable to more top-level ModelAdmin options.

Thoughts?

That is not a bad way, this is how I would go about it myself too. Actually this way you can add all sorts of extra functionality.

[David W. Lloyd]

Replying to Johannes Hoppe:

Replying to Carlton Gibson:

Thoughts?

That is not a bad way, this is how I would go about it myself too. Actually this way you can add all sorts of extra functionality.

I agree, that's a fine way to achieve the functionality, and if AutocompleteJsonView gets a bit more documentation, I guess that would be the default approach?

But my thinking is as follows: you can make the same exact argument about the *existing* "ordering" field - why have it, when you can do the same thing by modifying the queryset?

I personally believe the answer is: "Because it's a common enough use case that having a dedicated field makes it easier, more intuitive, and more explicit" - all of which are good things, and I think they apply to the autocomplete sorting the same as they do the ModelAdmin sorting.

Yes, that comes at the cost of adding another field to the API, but that's going to be the case with anything you want to make more explicit/intuitive. If there was an interest in conserving fields, it could be a dict? like:

autocomplete_view_options = {'ordering': 'name, 'other_useful_parameter_to_be_added_in_future': 'maybe?'}

...either way, while I see how to achieve the functionality in question myself (thanks!) and will have no problem whatsoever doing so, I still believe that the explicit decoupling would make sense, either via a single "autocomplete_ordering" field or a dict of extensible options including, initially, ordering. Other candidates might include caching, or perhaps providing a template.html to format each of the results within the select2 widget.

[Carlton Gibson]

...you can make the same exact argument about the *existing* "ordering" field - why have it, when you can do the same thing by modifying the queryset?

I think in the history of ModelAdmin itself, we've learnt that it's possible to have too much of a good thing when it comes to these declarative options.

ordering has been there forever, and there's no realistic way we can take it out. But I don't think it's likely we'd add it again today.

Instead I think we'd point to overriding get_queryset(), and just using a orderBy.

def get_queryset(self): 
    return self.model.objects.orderBy('-name') 

(... or such ...)

That would do. It's roughly the same, or sometime less, code than specifying ordering & co.
It's less magic. Less to remember. And less to have to go searching for when things behave unexpectedly.

Mutatis mutandis, I think in this case we should document ModelAdmin.autocomplete_view() and AutocompleteJsonView as the customisation point for the behaviour here.

(If there are one or two key configuration options then possibly AutocompleteJsonView could take init kwargs to as_view() to avoid subclassing in every case, but any such addition would need assessing separately, and probably afterwards.)

[Tim Graham]

​PR

[Denis Cornehl]

Since ModelAdmin.autocomplete_view is gone since Django 3.2, we can actually close this ticket, right?

​https://github.com/django/django/commit/3071660acfbdf4b5c59457c8e9dc345d5e8894c5

[Johannes Maron]

I must agree, the view does not exist anymore, or rather has been moved. It also has become a lot more complex and doesn't seem suited for user extension.

If anyone feels strongly about adding docs for the new implementation, feel free to reopen the issue for review.

[Mark Rossetti]

From what I can tell, removing ModelAdmin.autocomplete_view closed a pretty clean (if undocumented) option for modifying the label of items returned in the autocomplete Admin form. This Stack Overflow post illustrates: ​https://stackoverflow.com/questions/55629887/change-django-autocomplete-fields-label

After some exploration, I haven't found another way to accomplish the same thing, i.e. providing a custom label for the admin autocomplete view without just overriding the __str__ method on the model itself (which is rather heavy-handed).

I don't know enough to write docs on this issue myself, but I think that documentation of the new pattern (or another way to edit autocomplete form labels) would be very helpful.

[Mariusz Felisiak]

I appreciate you'd like to reopen the ticket, but please ​follow the triaging guidelines with regards to wontfix tickets and take this to DevelopersMailingList.

[Mark Rossetti]

Thanks, Mariusz. Was reopening (rather than filing a new ticket) based on the above request from Johannes Maron.

I'll follow the links that you posted and proceed from there.