Django + feincms。如何在管理界面中显示自组建列表？

Question

使用FeinCMS的Django可以显示表中的任何内容，看起来很不错。但是，如果我必须显示某些表中没有的数据呢？

这是我的代码：

##  models.py  ##
##  This is my main class.
class Application(models.Model):
    name = models.CharField(max_length=100)
    category = TreeForeignKey('Category', blank=False, null=False, verbose_name="name")
    ....

    class Meta:
        ordering = ('category__tree_id', 'category__lft', 'name')

##  This is my category class.
class Category(MPTTModel):
    name = models.CharField(max_length=50, unique = True)
    parent = TreeForeignKey('self', blank=True, null=True, related_name='children')

    class MPTTMeta:
        include_self = False
        order_insertion_by = ['name',]
        ordering = ['tree_id', 'lft']

##  This function returns list that I need to show in admin interface. As you can see I have to show name of every object which belongs to category.

    def get_trailer(self):
        application = Application()
        apps_list =  [application.__unicode__() for application in Application.objects.filter(category=self.id)]
        logging.error("This is apps_list from get_trailer!")
        logging.error(apps_list)
        return apps_list

##   Registering Category model as MPTT.
mptt.register(Category, order_insertion_by=['name'])

这里我们得到了管理界面的代码：

##  admin.py  ##
##  This is class for show Application.
class ApplicationAdmin(admin.ModelAdmin):
    list_display = ('name', 'category')
    list_filter = ('category',)
    ordering = ('category__lft',)

##  This is class for show Category.
class CategoryAdmin(tree_editor.TreeEditor):
    list_display = ('name', 'id',)
    list_filter = ('parent',)
    ordering = ('category__lft',)

确定。在这里，我们以树状格式获取所有类别。当我们点击任何类别时，我们只看到它的名字和父母。看看这个截图：

那么，如何通过django和feincms显示这个列表？我不想在表格中创建新的密钥。