use mixin instead of repeating patterns (#12977)

src/backend/InvenTree/InvenTree/admin.py

@@ -1,7 +1,6 @@
 """Admin classes."""
 
 from django.contrib import admin
-from django.http.request import HttpRequest
 from django.utils import timezone
 
 from allauth.usersessions.admin import UserSessionAdmin
@@ -11,14 +10,12 @@ from django_q.models import Schedule
 from djmoney.contrib.exchange.admin import RateAdmin
 from djmoney.contrib.exchange.models import Rate
 
+from common.admin_shared import NoAddAdminMixin, NoEditAdminMixin, ReadOnlyAdminMixin
 
-class CustomRateAdmin(RateAdmin):
+
+class CustomRateAdmin(NoAddAdminMixin, RateAdmin):
     """Admin interface for the Rate class."""
 
-    def has_add_permission(self, request: HttpRequest) -> bool:
-        """Disable the 'add' permission for Rate objects."""
-        return False
-
 
 admin.site.unregister(Rate)
 admin.site.register(Rate, CustomRateAdmin)
@@ -34,39 +31,19 @@ def run_schedule_now(modeladmin, request, queryset):
 run_schedule_now.short_description = 'Run selected tasks now'
 
 
-class ReadOnlyScheduleAdmin(ScheduleAdmin):
+class ReadOnlyScheduleAdmin(ReadOnlyAdminMixin, ScheduleAdmin):
     """Read-only admin interface for django-q Schedule objects."""
 
     actions = [run_schedule_now]
 
-    def has_add_permission(self, request: HttpRequest) -> bool:
-        """Prevent adding new Schedule objects."""
-        return False
-
-    def has_change_permission(self, request: HttpRequest, obj=None) -> bool:
-        """Prevent changing existing Schedule objects."""
-        return False
-
-    def has_delete_permission(self, request: HttpRequest, obj=None) -> bool:
-        """Prevent deleting Schedule objects."""
-        return False
-
 
 admin.site.unregister(Schedule)
 admin.site.register(Schedule, ReadOnlyScheduleAdmin)
 
 
-class InvenTreeUserSessionAdmin(UserSessionAdmin):
+class InvenTreeUserSessionAdmin(NoEditAdminMixin, UserSessionAdmin):
     """Admin interface for UserSession - view and delete only, no add or edit."""
 
-    def has_add_permission(self, request: HttpRequest) -> bool:
-        """Prevent creating sessions via admin."""
-        return False
-
-    def has_change_permission(self, request: HttpRequest, obj=None) -> bool:
-        """Prevent editing sessions via admin."""
-        return False
-
 
 admin.site.unregister(UserSession)
 admin.site.register(UserSession, InvenTreeUserSessionAdmin)

src/backend/InvenTree/common/admin.py

@@ -4,6 +4,7 @@ from django.contrib import admin
 
 import common.models
 import common.validators
+from common.admin_shared import NoEditAdminMixin, ReadOnlyAdminMixin
 
 
 @admin.register(common.models.ParameterTemplate)
@@ -89,7 +90,7 @@ class AttachmentAdmin(admin.ModelAdmin):
 
 
 @admin.register(common.models.DataOutput)
-class DataOutputAdmin(admin.ModelAdmin):
+class DataOutputAdmin(NoEditAdminMixin, admin.ModelAdmin):
     """Admin interface for DataOutput objects - view and delete only."""
 
     list_display = ('user', 'created', 'output_type', 'output')
@@ -106,17 +107,9 @@ class DataOutputAdmin(admin.ModelAdmin):
 
     autocomplete_fields = ('user',)
 
-    def has_add_permission(self, request):
-        """Prevent addition of new DataOutput objects via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of DataOutput objects via the admin interface."""
-        return False
-
 
 @admin.register(common.models.BarcodeScanResult)
-class BarcodeScanResultAdmin(admin.ModelAdmin):
+class BarcodeScanResultAdmin(NoEditAdminMixin, admin.ModelAdmin):
     """Admin interface for BarcodeScanResult objects - read-only audit log."""
 
     list_display = ('data', 'timestamp', 'user', 'endpoint', 'result')
@@ -127,14 +120,6 @@ class BarcodeScanResultAdmin(admin.ModelAdmin):
 
     autocomplete_fields = ('user',)
 
-    def has_add_permission(self, request):
-        """Prevent addition of new BarcodeScanResult objects via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of BarcodeScanResult objects via the admin interface."""
-        return False
-
 
 @admin.register(common.models.ProjectCode)
 class ProjectCodeAdmin(admin.ModelAdmin):
@@ -196,24 +181,16 @@ class WebhookAdmin(admin.ModelAdmin):
 
 
 @admin.register(common.models.NotificationEntry)
-class NotificationEntryAdmin(admin.ModelAdmin):
+class NotificationEntryAdmin(NoEditAdminMixin, admin.ModelAdmin):
     """Admin settings for NotificationEntry - view and delete only."""
 
     list_display = ('key', 'uid', 'updated')
 
     search_fields = ('key', 'uid')
 
-    def has_add_permission(self, request):
-        """Prevent addition of new NotificationEntry objects via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of NotificationEntry objects via the admin interface."""
-        return False
-
 
 @admin.register(common.models.NotificationMessage)
-class NotificationMessageAdmin(admin.ModelAdmin):
+class NotificationMessageAdmin(NoEditAdminMixin, admin.ModelAdmin):
     """Admin settings for NotificationMessage - view and delete only."""
 
     list_display = (
@@ -232,46 +209,18 @@ class NotificationMessageAdmin(admin.ModelAdmin):
 
     autocomplete_fields = ('user',)
 
-    def has_add_permission(self, request):
-        """Prevent addition of new NotificationMessage objects via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of NotificationMessage objects via the admin interface."""
-        return False
-
 
 @admin.register(common.models.NewsFeedEntry)
-class NewsFeedEntryAdmin(admin.ModelAdmin):
+class NewsFeedEntryAdmin(NoEditAdminMixin, admin.ModelAdmin):
     """Admin settings for NewsFeedEntry - view and delete only."""
 
     list_display = ('title', 'author', 'published', 'summary')
 
     search_fields = ('title', 'author', 'summary')
 
-    def has_add_permission(self, request):
-        """Prevent addition of new NewsFeedEntry objects via the admin interface."""
-        return False
 
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of NewsFeedEntry objects via the admin interface."""
-        return False
-
-
-class ReadOnlyAdmin(admin.ModelAdmin):
-    """Base admin class that prevents all modifications."""
-
-    def has_add_permission(self, request):
-        """Prevent addition of new objects via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of objects via the admin interface."""
-        return False
-
-    def has_delete_permission(self, request, obj=None):
-        """Prevent deletion of objects via the admin interface."""
-        return False
+class ReadOnlyAdmin(ReadOnlyAdminMixin, admin.ModelAdmin):
+    """Admin class that makes the model read-only."""
 
 
 admin.site.register(common.models.WebhookMessage, ReadOnlyAdmin)

src/backend/InvenTree/common/admin_shared.py

@@ -0,0 +1,25 @@
+"""Helpers for controlling admin interface permissions."""
+
+
+class NoAddAdminMixin:
+    """Mixin to prevent addition of new objects via the admin interface."""
+
+    def has_add_permission(self, request, obj=None):
+        """Prevent addition of new objects via the admin interface."""
+        return False
+
+
+class NoEditAdminMixin(NoAddAdminMixin):
+    """Base admin class that prevents editing of objects."""
+
+    def has_change_permission(self, request, obj=None):
+        """Prevent modification of objects via the admin interface."""
+        return False
+
+
+class ReadOnlyAdminMixin(NoEditAdminMixin):
+    """Base admin class that prevents all modifications."""
+
+    def has_delete_permission(self, request, obj=None):
+        """Prevent deletion of objects via the admin interface."""
+        return False

src/backend/InvenTree/machine/admin.py

@@ -2,20 +2,17 @@
 
 from django.contrib import admin
 
+from common.admin_shared import NoAddAdminMixin
 from machine import models
 
 
-class MachineSettingInline(admin.TabularInline):
+class MachineSettingInline(NoAddAdminMixin, admin.TabularInline):
     """Inline admin class for MachineSetting."""
 
     model = models.MachineSetting
 
     readonly_fields = ['key', 'config_type']
 
-    def has_add_permission(self, request, obj):
-        """The machine settings should not be meddled with manually."""
-        return False
-
 
 @admin.register(models.MachineConfig)
 class MachineConfigAdmin(admin.ModelAdmin):

src/backend/InvenTree/plugin/admin.py

@@ -2,6 +2,7 @@
 
 from django.contrib import admin
 
+from common.admin_shared import NoAddAdminMixin
 from plugin import models
 from plugin.registry import registry as pl_registry
 
@@ -34,29 +35,21 @@ def plugin_deactivate(modeladmin, request, queryset):
     plugin_update(queryset, False)
 
 
-class PluginSettingInline(admin.TabularInline):
+class PluginSettingInline(NoAddAdminMixin, admin.TabularInline):
     """Inline admin class for PluginSetting."""
 
     model = models.PluginSetting
 
     readonly_fields = ['key']
 
-    def has_add_permission(self, request, obj):
-        """The plugin settings should not be meddled with manually."""
-        return False
 
-
-class PluginUserSettingInline(admin.TabularInline):
+class PluginUserSettingInline(NoAddAdminMixin, admin.TabularInline):
     """Inline admin class for PluginUserSetting."""
 
     model = models.PluginUserSetting
 
     readonly_fields = ['key']
 
-    def has_add_permission(self, request, obj):
-        """The plugin user settings should not be meddled with manually."""
-        return False
-
 
 class PluginConfigAdmin(admin.ModelAdmin):
     """Custom admin with restricted id fields."""

src/backend/InvenTree/stock/admin.py

@@ -3,6 +3,8 @@
 from django.contrib import admin
 from django.db.models import Count
 
+from common.admin_shared import ReadOnlyAdminMixin
+
 from .models import (
     StockItem,
     StockItemTestResult,
@@ -77,7 +79,7 @@ class StockItemAdmin(admin.ModelAdmin):
 
 
 @admin.register(StockItemTracking)
-class StockTrackingAdmin(admin.ModelAdmin):
+class StockTrackingAdmin(ReadOnlyAdminMixin, admin.ModelAdmin):
     """Admin class for StockTracking - read-only to preserve audit trail integrity."""
 
     list_display = ('item', 'date', 'label')
@@ -86,18 +88,6 @@ class StockTrackingAdmin(admin.ModelAdmin):
 
     autocomplete_fields = ['item']
 
-    def has_add_permission(self, request):
-        """Prevent addition of new tracking entries via the admin interface."""
-        return False
-
-    def has_change_permission(self, request, obj=None):
-        """Prevent modification of tracking entries via the admin interface."""
-        return False
-
-    def has_delete_permission(self, request, obj=None):
-        """Prevent deletion of tracking entries via the admin interface."""
-        return False
-
 
 @admin.register(StockItemTestResult)
 class StockItemTestResultAdmin(admin.ModelAdmin):