Ticket #6776: 6776_modeladmin_fix.2.diff

/dev/null

@@ +1 @@
+
+class ModelAdminCache(object):
+    """
+    A cache of ModelAdmin classes. This ensures that once a ModelAdmin is
+    declared that it will remain the sole class. Basically providing a
+    guranteed ModelAdmin idenity.
+    """
+    def __init__(self):
+        self.modeladmin_store = {}
+    
+    def get(self, key):
+        return self.modeladmin_store[key]
+    
+    def register(self, *admin_classes):
+        for admin_class in admin_classes:
+            key = ".".join(admin_class.__module__.split(".")[-2:] + [admin_class.__name__])
+            if key in self.modeladmin_store:
+                continue
+            self.modeladmin_store[key] = admin_class
+
+admin_class_cache = ModelAdminCache()

a/django/contrib/admin/options.py

@@ -4 +4 @@
-from django.newforms.models import _modelform_factory, _inlineformset_factory
-from django.contrib.contenttypes.models import ContentType
-from django.contrib.admin import widgets
+from django.contrib.admin.loading import admin_class_cache
-from django.contrib.admin.util import get_deleted_objects
-from django.core.exceptions import ImproperlyConfigured, PermissionDenied
-from django.db import models, transaction
@@ -124 +125 @@
-        attrs = classes and {'class': u' '.join(classes)} or {}
-        return self.field.label_tag(contents=contents, attrs=attrs)
-
+class ModelAdminMetaclass(type):
+    def __new__(cls, name, bases, attrs):
+        new_class = forms.MediaDefiningClass.__new__(cls, name, bases, attrs)
+        try:
+            parents = [b for b in bases if issubclass(b, ModelAdmin)]
+            if not parents:
+                return new_class
+        except NameError:
+            return new_class
+        # put this in some sort of registry
+        admin_class_cache.register(new_class)
+        # due to the way imports happening only use the admin class that is
+        # already registered.
+        return admin_class_cache.get(".".join(new_class.__module__.split(".")[-2:] + [new_class.__name__]))
+
-class BaseModelAdmin(object):
-    """Functionality common to both ModelAdmin and InlineAdmin."""
-    raw_id_fields = ()
@@ -200 +216 @@
-
-class ModelAdmin(BaseModelAdmin):
-    "Encapsulates all admin options and functionality for a given model."
-forms.MediaDefiningC
+ModelAdminMetac
-
-    list_display = ('__str__',)
-    list_display_links = ()

a/django/contrib/admin/sites.py

@@ -76 +76 @@
-        if isinstance(model_or_iterable, ModelBase):
-            model_or_iterable = [model_or_iterable]
-        for model in model_or_iterable:
-
-' % model.__name__
+ and self._registry[model].__class__ is not admin_class
+ to %s' % (model.__name__, self._registry[model].__class__.__name__)
-            self._registry[model] = admin_class(model, self)
-
-    def unregister(self, model_or_iterable):

a/tests/regressiontests/modeladmin/models.py

@@ -17 +17 @@
-
->>> request = None
-
+Ensure that only the first ModelAdmin ever declared is the only one for the
+app.
+
+>>> class OneBandAdmin(ModelAdmin):
+...     pass
+
+>>> class TwoBandAdmin(ModelAdmin):
+...     pass
+
+>>> one_band_admin_id = id(OneBandAdmin)
+>>> id(OneBandAdmin) != id(TwoBandAdmin)
+True
+
+>>> class OneBandAdmin(ModelAdmin):
+...     pass
+
+>>> one_band_admin_id == id(OneBandAdmin)
+True
+
->>> band = Band(name='The Doors', bio='')
-
-Under the covers, the admin system will initialize ModelAdmin with a Model
@@ -96 +115 @@
-...     class Meta:
-...         model = Band
-
-
+Another
-...     form = AdminBandForm
-
-
+Another
->>> ma.get_form(request).base_fields.keys()
-['name', 'bio', 'sign_date', 'delete']
->>> type(ma.get_form(request).base_fields['sign_date'].widget)