added BaseModelAdminMixin

apps/establishment/admin.py

@@ -4,6 +4,7 @@ from django.contrib.contenttypes.admin import GenericTabularInline
 from django.utils.translation import gettext_lazy as _
 
 from comment.models import Comment
+from utils.admin import BaseModelAdminMixin
 from establishment import models
 from main.models import Award
 from review import models as review_models
@@ -57,7 +58,7 @@ class EstablishmentAdmin(admin.ModelAdmin):
 
 
 @admin.register(models.Position)
-class PositionAdmin(admin.ModelAdmin):
+class PositionAdmin(BaseModelAdminMixin):
     """Position admin."""
 
 
@@ -68,7 +69,7 @@ class PlateInline(admin.TabularInline):
 
 
 @admin.register(models.Menu)
-class MenuAdmin(admin.ModelAdmin):
+class MenuAdmin(BaseModelAdminMixin):
     """Menu admin."""
     list_display = ['id', 'category_translated']
     inlines = [

apps/news/admin.py

@@ -3,6 +3,7 @@ from django.conf import settings
 
 from news import models
 from .tasks import send_email_with_news
+from utils.admin import BaseModelAdminMixin
 
 
 @admin.register(models.NewsType)
@@ -24,7 +25,7 @@ send_email_action.short_description = "Send the selected news by email"
 
 
 @admin.register(models.News)
-class NewsAdmin(admin.ModelAdmin):
+class NewsAdmin(BaseModelAdminMixin):
     """News admin."""
     raw_id_fields = ('address',)
     actions = [send_email_action]

apps/review/admin.py

@@ -1,8 +1,9 @@
 """Admin page for app Review"""
 from . import models
 from django.contrib import admin
+from utils.admin import BaseModelAdminMixin
 
 
 @admin.register(models.Review)
-class ReviewAdminModel(admin.ModelAdmin):
+class ReviewAdminModel(BaseModelAdminMixin):
     """Admin model for model Review."""

apps/utils/admin.py

@@ -0,0 +1,36 @@
+"""Mixins for admin models."""
+from django.contrib import admin
+from django.db.models import ForeignKey
+
+
+class BaseModelAdminMixin(admin.ModelAdmin):
+    """
+    Class that overridden ModelAdmin and adds to readonly_fields attr
+    persisted fields like created_by, modified_by.
+    """
+
+    _PERSISTENT_READ_ONLY_FIELDS = ['created_by', 'modified_by']
+
+    def _get_fk_field_names(self, fields: iter):
+        """
+        Return an iterable object which contains FK model fields.
+        :param fields: iterable
+        :return: iterable
+        """
+        foreign_key_fields = []
+        for field in fields:
+            if isinstance(field, ForeignKey):
+                foreign_key_fields.append(field.name)
+        return foreign_key_fields
+
+    def get_readonly_fields(self, request, obj=None):
+        """
+        Hook for specifying custom readonly fields.
+        """
+        _readonly_fields = list(self.readonly_fields)
+        fk_field_names = self._get_fk_field_names(self.model._meta.fields)
+
+        for field_name in fk_field_names:
+            if field_name in self._PERSISTENT_READ_ONLY_FIELDS:
+                _readonly_fields.append(field_name)
+        return tuple(_readonly_fields)