#32993: Refactor AutocompleteJsonView to support extra fields in autocomplete
response
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Reporter: mrts | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: contrib.admin | Version: 3.2
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 1
UI/UX: 0 |
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Adding data attributes to items in ordinary non-autocomplete foreign key
fields that use {{{forms.widgets.Select}}}-based widgets is relatively
easy. This enables powerful and dynamic admin site customizations where
fields from related models are updated immediately when users change the
selected item.
However, adding new attributes to autocomplete field results currently
requires extending
{{{contrib.admin.views.autocomplete.AutocompleteJsonView}}} and fully
overriding the {{{AutocompleteJsonView.get()}}} method. Here's an example:
{{{#!python
class MyModelAdmin(admin.ModelAdmin):
def get_urls(self):
return [
path('autocomplete/',
CustomAutocompleteJsonView.as_view(admin_site=self.admin_site))
if url.pattern.match('autocomplete/')
else url for url in super().get_urls()
]
class CustomAutocompleteJsonView(AutocompleteJsonView):
def get(self, request, *args, **kwargs):
self.term, self.model_admin, self.source_field, to_field_name =
self.process_request(request)
if not self.has_perm(request):
raise PermissionDenied
self.object_list = self.get_queryset()
context = self.get_context_data()
return JsonResponse({
'results': [
{'id': str(getattr(obj, to_field_name)), 'text': str(obj),
'notes': obj.notes} # <-- customization here
for obj in context['object_list']
],
'pagination': {'more': context['page_obj'].has_next()},
})
}}}
The problem with this is that as {{{AutocompleteJsonView.get()}}} keeps
evolving, there's quite a lot of maintenance overhead required to catch
up.
The solutions is simple, side-effect- and risk-free: adding a result
customization extension point to {{{get()}}} by moving the lines that
construct the results inside {{{JsonResponse}}} to a separate method. So
instead of
{{{#!python
return JsonResponse({
'results': [
{'id': str(getattr(obj, to_field_name)), 'text': str(obj)}
for obj in context['object_list']
],
'pagination': {'more': context['page_obj'].has_next()},
})
}}}
there would be
{{{#!python
return JsonResponse({
'results': [
self.obj_to_dict(obj, to_field_name) for obj in
context['object_list']
],
'pagination': {'more': context['page_obj'].has_next()},
})
}}}
where {{{obj_to_dict()}}} contains the original object to dictionary
conversion code that would be now easy to override:
{{{#!python
def obj_to_dict(self, obj, to_field_name):
return {'id': str(getattr(obj, to_field_name)), 'text': str(obj)}
}}}
The example {{{CustomAutocompleteJsonView}}} from above would now become
succinct and maintainable:
{{{#!python
class CustomAutocompleteJsonView(AutocompleteJsonView):
def obj_to_dict(self, obj, to_field_name):
return super.obj_to_dict(obj, to_field_name) | {'notes':
obj.notes}
}}}
What do you think, is this acceptable? I'm more than happy to provide the
patch.
--
Ticket URL: <https://code.djangoproject.com/ticket/32993>
Django <https://code.djangoproject.com/>
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