better Resource.get_model and Resource.get_queryset methods (directly inspired from generic.DetailView)

djangorestframework/resources.py

@@ -1,6 +1,7 @@
 from django import forms
 from django.core.urlresolvers import reverse, get_urlconf, get_resolver, NoReverseMatch
 from django.db import models
+from django.core.exceptions import ImproperlyConfigured
 
 from djangorestframework.response import ErrorResponse
 from djangorestframework.serializer import Serializer, _SkipField
@@ -529,18 +530,36 @@ class ModelResource(FormResource):
 
     def get_model(self):
         """
-        Return the model class for this view.
+        Return the model class for this resource.
         """
-        return getattr(self, 'model', getattr(self.view, 'model', None))
+        model = getattr(self, 'model', None)
+        if model is None:
+            model = getattr(self.view, 'model', None)
+            if model is None:
+                raise ImproperlyConfigured(u"%(cls)s is missing a model. Define "
+                                           u"%(cls)s.model." % {
+                                                'cls': self.__class__
+                                           })
+        return model
 
     def get_queryset(self):
         """
         Return the queryset that should be used when retrieving or listing
         instances.
         """
-        return getattr(self, 'queryset',
-                    getattr(self.view, 'queryset',
-                        self.get_model().objects.all()))
+        queryset = getattr(self, 'queryset', None)
+        if queryset is None:
+            queryset = getattr(self.view, 'queryset', None)
+            if queryset is None:
+                try:
+                    model = self.get_model()
+                except ImproperlyConfigured:
+                    raise ImproperlyConfigured(u"%(cls)s is missing a queryset. Define "
+                                               u"%(cls)s.model or %(cls)s.queryset." % {
+                                                    'cls': self.__class__
+                                               })
+                queryset = model._default_manager.all()
+        return queryset._clone()
 
     def get_ordering(self):
         """