Features: 1) Replace I18NTabTranslationAdmin with I18NFieldsetMixin for admin classes; 2) Introduce _TranslationInline for managing translation fields dynamically; 3) Add created and modified fields to readonly_fields in Category admin class;

Fixes: 1) Resolve unnecessary imports from `modeltranslation.admin` and streamline admin imports;

Extra: 1) Refactor translation logic into `get_inline_instances` for improved modularity and clarity.

core/admin.py

@@ -4,13 +4,12 @@ from constance.admin import ConstanceAdmin as BaseConstanceAdmin
 from django.apps import apps
 from django.contrib import admin
 from django.contrib.admin import ModelAdmin, TabularInline
+from django.contrib.admin.options import InlineModelAdmin
 from django.contrib.gis.admin import GISModelAdmin
 from django.db.models import Model
+from django.forms import modelform_factory
 from django.urls import path
 from django.utils.translation import gettext_lazy as _
-from modeltranslation.admin import (
-    TabbedExternalJqueryTranslationAdmin,
-)
 from modeltranslation.translator import translator
 from modeltranslation.utils import get_translation_fields
 from mptt.admin import DraggableMPTTAdmin
@@ -48,41 +47,50 @@ SECTION_RELATIONS = _("relations")
 
 class I18NFieldsetMixin:
     model: type[Model]
-    """
-    Pulls all <field>_<lang> translation columns out of the regular
-    fieldsets and tucks them into one extra fieldset/tab called "I18N".
-    """
-
-    def get_fieldsets(self, request, obj=None):
-        base_fieldsets = super().get_fieldsets(request, obj)
 
+    def get_inline_instances(self, request, obj=None):
+        inlines = super().get_inline_instances(request, obj)
         trans_opts = translator.get_options_for_model(self.model)
         translation_fields = []
         for orig in trans_opts.local_fields:
-            translation_fields.extend(get_translation_fields(orig))
+            translation_fields += get_translation_fields(orig)
 
-        cleaned = []
+        class _TranslationInline(InlineModelAdmin[self.model, self.model]):
-        for title, opts in base_fieldsets:
+            model = self.model
-            original = list(opts.get("fields", []))
+            form = modelform_factory(
-            filtered = [f for f in original if f not in translation_fields]
+                self.model,
-            opts = opts.copy()
+                fields=translation_fields,
-            opts["fields"] = filtered
+                formfield_callback=lambda f, **kw: super(
-            cleaned.append((title, opts))
+                    I18NFieldsetMixin, self
-
+                ).formfield_for_dbfield(f, request, **kw),
-        cleaned.append(
-            (
-                SECTION_I18N,
-                {
-                    "classes": ("suit-tab-i18n",),
-                    "fields": tuple(translation_fields),
-                },
             )
-        )
+            template = "admin/edit_inline/tabular.html"
-        return cleaned
+            is_navtab = True
+            verbose_name = _("translations")
+            verbose_name_plural = _("translations")
+            extra = 0
 
+            def get_queryset(self, request):
+                return (
+                    self.model.objects.filter(pk=obj.pk)
+                    if obj
+                    else self.model.objects.none()
+                )
 
-class I18NTabTranslationAdmin(I18NFieldsetMixin, TabbedExternalJqueryTranslationAdmin):
+            def get_formset(self, request, obj=None, **kw):
-    pass
+                return super().get_formset(
+                    request,
+                    obj,
+                    **{
+                        **kw,
+                        "form": self.form,
+                        "fields": translation_fields,
+                        "exclude": [],
+                    },
+                )
+
+        inlines.append(_TranslationInline(self.model, self.admin_site))
+        return inlines
 
 
 class BasicModelAdmin(ModelAdmin):
@@ -121,7 +129,7 @@ class AttributeValueInline(TabularInline):
 
 
 @admin.register(AttributeGroup)
-class AttributeGroupAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class AttributeGroupAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name", "modified")
     search_fields = (
         "uuid",
@@ -144,7 +152,7 @@ class AttributeGroupAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
 
 
 @admin.register(Attribute)
-class AttributeAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class AttributeAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name", "group", "value_type", "modified")
     list_filter = ("value_type", "group", "is_active")
     search_fields = ("uuid", "name", "group__name")
@@ -152,7 +160,7 @@ class AttributeAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
 
 
 @admin.register(AttributeValue)
-class AttributeValueAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class AttributeValueAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("attribute", "value", "modified")
     list_filter = ("attribute__group", "is_active")
     search_fields = ("uuid", "value", "attribute__name")
@@ -168,7 +176,7 @@ class CategoryChildrenInline(admin.TabularInline):
 
 
 @admin.register(Category)
-class CategoryAdmin(DraggableMPTTAdmin, BasicModelAdmin, I18NTabTranslationAdmin):
+class CategoryAdmin(DraggableMPTTAdmin, BasicModelAdmin, I18NFieldsetMixin):
     mptt_indent_field = "name"
     list_display = ("indented_title", "parent", "is_active", "modified")
     # noinspection PyUnresolvedReferences
@@ -214,6 +222,8 @@ class CategoryAdmin(DraggableMPTTAdmin, BasicModelAdmin, I18NTabTranslationAdmin
     readonly_fields = (
         "uuid",
         "slug",
+        "created",
+        "modified",
     )
 
     def indented_title(self, instance):
@@ -224,7 +234,7 @@ class CategoryAdmin(DraggableMPTTAdmin, BasicModelAdmin, I18NTabTranslationAdmin
 
 
 @admin.register(Brand)
-class BrandAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class BrandAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name",)
     list_filter = ("categories", "is_active")
     search_fields = (
@@ -255,7 +265,7 @@ class StockInline(TabularInline):
 
 
 @admin.register(Product)
-class ProductAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class ProductAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = (
         "name",
         "partnumber",
@@ -340,13 +350,13 @@ class ProductAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
 
 
 @admin.register(ProductTag)
-class ProductTagAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class ProductTagAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name",)
     search_fields = ("name",)
 
 
 @admin.register(CategoryTag)
-class CategoryTagAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class CategoryTagAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name",)
     search_fields = ("name",)
 
@@ -458,7 +468,7 @@ class PromoCodeAdmin(BasicModelAdmin):
 
 
 @admin.register(Promotion)
-class PromotionAdmin(BasicModelAdmin, I18NTabTranslationAdmin):
+class PromotionAdmin(BasicModelAdmin, I18NFieldsetMixin):
     list_display = ("name", "discount_percent", "modified")
     search_fields = ("name",)
     autocomplete_fields = ("products",)