class MyCategory(models.Model):
    caption = models.CharField(max_length=40)
    
    class Meta:
        ordering=['id']
    def __unicode__(self):
        return self.caption
class MyItem(models.Model):
    category = models.ForeignKey(TodoCategory)
    caption = models.CharField(max_length=40)
    description = models.CharField(max_length=512)
    created = models.DateTimeField('Created time'), default=timezone.now)
    createdby = models.ForeignKey(MyUser)
    ....
    class Meta:
        ordering=['created']
        app_label = 'mysmallapp'
        permissions = (
            ('moderate_myitems', 'View, update and delete any myitems'),
        )
    def __unicode__(self):
        return self.caption
    def get_notes(self):
        return MyNote.objects.filter(itemlink=self)
class MyNote(models.Model):
    itemlink = models.ForeignKey(MyItem)
    text = models.CharField(max_length=512)
    created = models.DateTimeField('Created time'), default=timezone.now)
    ...
    
    class Meta:
        ordering=['created']
        app_label = 'mysmallapp'
        permissions = (
            ('moderate_notes', 'View, update and delete any note'),
        )

urlpatterns = patterns('',
                       url(r'^item/add/$', login_required(MyItemCreateView.as_view()), 
			   name='myitem_add'),
		       url(r'^item/(?P<pk>\d+)/edit/$', login_required(MyItemEditView.as_view()), 
			   name='myitem_edit'),
		       url(r'^item/(?P<pk>\d+)/delete/$', login_required(MyItemDeleteView.as_view()), 
			   name='myitem_delete'),
		       url(r'^item/(?P<numer>\d+)/add/$', login_required(MyNoteCreateView.as_view()), 
			   name='mynote_add'),
		       url(r'^note/(?P<pk>\d+)/edit/$', login_required(MyNoteEditView.as_view()), 
			   name='mynote_edit'),
		       url(r'^note/(?P<pk>\d+)/delete/$', login_required(MyNoteDeleteView.as_view()), 
			   name='mynote_delete'),
                       )

def get_mynotes_queryset(self):
    if self.request.user.has_perm('mysmallapp.moderate_notes'):
        return MyNote.objects.all()
    else:
        return MyNote.objects.filter(itemlink__createdby=self.request.user)
class MyNoteEditView(UpdateView):
    model = MyNote
    form_class = MyNoteForm
    ...
    get_queryset = get_mynotes_queryset
class MyNoteDeleteView(DeleteView):
    model = MyNote
    template_name = ...
    ...
    
    get_queryset = get_mynotes_queryset

    def form_valid(self, form):
        nlink = get_object_or_404(MyItem, pk=self.kwargs['numer'])
        form.instance.itemlink = nlink
        return super(MyNoteCreateView, self).form_valid(form)

class PermissionResolverMixin(object):
    def dispatc(self, request, *args, **kw):
        if ....
              self.item = ...
        else:
              raise PermissionDenied()
        return super(PermissionResolverMixin, self).dispatc(self, request, *args, **kw)
class MyView(PermissionResolverMixin, UpdateView):
     pass