Dropdown filters

Dropdown filters will display a select field with a list of options. Unfold contains two types of dropdowns: ChoicesDropdownFilter and RelatedDropdownFilter.

The difference between them is that ChoicesDropdownFilter will collect a list of options based on the choices attribute of the model field so most commonly it will be used in combination with CharField with specified choices. On the other hand, RelatedDropdownFilter needs a one-to-many or many-to-many foreign key to display options.

# admin.py

from django.contrib import admin
from django.contrib.auth.models import User
from unfold.admin import ModelAdmin
from unfold.contrib.filters.admin import (
    ChoicesDropdownFilter,
    MultipleChoicesDropdownFilter,
    RelatedDropdownFilter,
    MultipleRelatedDropdownFilter,
    DropdownFilter,
    MultipleDropdownFilter
)


class CustomDropdownFilter(DropdownFilter):
    title = _("Custom dropdown filter")
    parameter_name = "query_param_in_uri"

    def lookups(self, request, model_admin):
        return [
            ["option_1", _("Option 1")],
            ["option_2", _("Option 2")],
        ]

    def queryset(self, request, queryset):
        if self.value() not in EMPTY_VALUES:
            # Here write custom query
            return queryset.filter(your_field=self.value())

        return queryset


@admin.register(User)
class MyAdmin(ModelAdmin):
    list_filter_submit = True  # Submit button at the bottom of the filter
    list_filter = [
        CustomDropdownFilter,
        ("modelfield_with_choices", ChoicesDropdownFilter),
        ("modelfield_with_choices_multiple", MultipleChoicesDropdownFilter),
        ("modelfield_with_foreign_key", RelatedDropdownFilter)
        ("modelfield_with_foreign_key_multiple", MultipleRelatedDropdownFilter)
    ]

Note: At the moment Unfold does not implement a dropdown with an autocomplete functionality, so it is important not to use dropdowns displaying large datasets.

Note: All dropdowns are using Select2 for better UX by default. Native implementation with simple select dropdown is not available.