Add Select2 mixin that uses Django's own select template

django_select2/__init__.py

@@ -9,5 +9,5 @@
 """
 from django import get_version
 
-if get_version() < '3.2':
+if get_version() < "3.2":
     default_app_config = "django_select2.apps.Select2AppConfig"

django_select2/forms.py

@@ -54,7 +54,7 @@
 
 import django
 from django import forms
-from django.contrib.admin.widgets import SELECT2_TRANSLATIONS
+from django.contrib.admin.widgets import SELECT2_TRANSLATIONS, AutocompleteMixin
 from django.core import signing
 from django.db.models import Q
 from django.forms.models import ModelChoiceIterator
@@ -65,7 +65,9 @@
 from .conf import settings
 
 if django.VERSION < (4, 0):
-    from django.contrib.admin.utils import lookup_needs_distinct as lookup_spawns_duplicates
+    from django.contrib.admin.utils import (
+        lookup_needs_distinct as lookup_spawns_duplicates,
+    )
 else:
     from django.contrib.admin.utils import lookup_spawns_duplicates
 
@@ -79,6 +81,9 @@ class Select2Mixin:
     form media.
     """
 
+    css_class_name = "django-select2"
+    theme = None
+
     empty_label = ""
 
     def __init__(self, *args, **kwargs):
@@ -90,7 +95,7 @@ def build_attrs(self, base_attrs, extra_attrs=None):
         default_attrs = {
             "lang": self.i18n_name,
             "data-minimum-input-length": 0,
-            "data-theme": settings.SELECT2_THEME,
+            "data-theme": self.theme or settings.SELECT2_THEME,
         }
         if self.is_required:
             default_attrs["data-allow-clear"] = "false"
@@ -102,9 +107,9 @@ def build_attrs(self, base_attrs, extra_attrs=None):
         attrs = super().build_attrs(default_attrs, extra_attrs=extra_attrs)
 
         if "class" in attrs:
-            attrs["class"] += " django-select2"
+            attrs["class"] += " " + self.css_class_name
         else:
-            attrs["class"] = "django-select2"
+            attrs["class"] = self.css_class_name
         return attrs
 
     def optgroups(self, name, value, attrs=None):
@@ -137,6 +142,20 @@ def media(self):
         )
 
 
+class Select2AdminMixin:
+    """Select2 mixin that uses Django's own select template."""
+
+    css_class_name = "admin-autocomplete"
+    theme = "admin-autocomplete"
+
+    @property
+    def media(self):
+        return forms.Media(
+            js=Select2Mixin().media._js,
+            css=AutocompleteMixin(None, None).media._css,
+        )
+
+
 class Select2TagMixin:
     """Mixin to add select2 tag functionality."""
 

tests/test_forms.py

@@ -21,6 +21,7 @@
     ModelSelect2TagWidget,
     ModelSelect2Widget,
     Select2Widget,
+    Select2AdminMixin,
 )
 from tests.testapp import forms
 from tests.testapp.forms import (
@@ -175,6 +176,23 @@ def test_theme_setting(self, settings):
         assert 'data-theme="classic"' in widget.render("name", None)
 
 
+class TestSelect2AdminMixin:
+    def test_media(self):
+        translation.activate("en")
+        assert tuple(Select2AdminMixin().media._js) == (
+            f"https://cdnjs.cloudflare.com/ajax/libs/select2/{settings.SELECT2_LIB_VERSION}/js/select2.min.js",
+            f"https://cdnjs.cloudflare.com/ajax/libs/select2/{settings.SELECT2_LIB_VERSION}/js/i18n/en.js",
+            "django_select2/django_select2.js",
+        )
+
+        assert dict(Select2AdminMixin().media._css) == {
+            "screen": [
+                "admin/css/vendor/select2/select2.min.css",
+                "admin/css/autocomplete.css",
+            ]
+        }
+
+
 class TestSelect2MixinSettings:
     def test_default_media(self):
         sut = Select2Widget()