Django Autocomplete with limit_choices_to support

autocomplete.py

from django.contrib.admin.options import BaseModelAdmin
from django.contrib.admin.views.autocomplete import AutocompleteJsonView
from django.contrib.admin.widgets import (
    AutocompleteSelect, AutocompleteSelectMultiple,
)
from django.utils.http import urlencode
from urllib.parse import unquote, quote_plus, parse_qsl


class AutocompleteUrl(object):
    def get_url_params(self):
        return {
            'limit_choices_to': quote_plus(urlencode(self.rel.limit_choices_to))
        }

    def get_url(self):
        url = super().get_url()
        return url + '?' + urlencode(self.get_url_params())
        
         
class ManyToManyAutocompleteSelect(AutocompleteUrl, AutocompleteSelectMultiple):
    pass
    
    
class ForeignKeyAutocompleteSelect(AutocompleteUrl, AutocompleteSelect):
    pass
    

class LimitAutocompleteJsonView(AutocompleteJsonView):
    # Filter the results with the arguments passed to the url
    def get_queryset(self):
        qs = super().get_queryset()
        limit_choices_to = self.request.GET.get('limit_choices_to')
        if not limit_choices_to:
            return qs
        params = dict(parse_qsl(unquote(limit_choices_to)))
        return qs.complex_filter(params)
    
    
class HelperAdmin(BaseModelAdmin):
    limit_choices_fields = []
    
    def autocomplete_view(self, request):
        return LimitAutocompleteJsonView.as_view(model_admin=self)(request)

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name in self.limit_choices_fields:
            db = kwargs.get('using')
            kwargs['widget'] = ForeignKeyAutocompleteSelect(
                db_field.remote_field,
                self.admin_site,
                using=db)
        return super().formfield_for_foreignkey(db_field, request, **kwargs)
      
    def formfield_for_manytomany(self, db_field, request, **kwargs):
        if db_field.name in self.limit_choices_fields:
            db = kwargs.get('using')
            kwargs['widget'] = ManyToManyAutocompleteSelect(
                db_field.remote_field,
                self.admin_site,
                using=db)
        return super().formfield_for_manytomany(db_field, request, **kwargs)