带django_mptt信号的post_save模型

Question

class Category(MPTTModel):
    name = models.CharField(max_length=256)
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)

    class MPTTMeta:
        order_insertion_by = ['name']



@receiver(post_save)
def translate_name(sender, instance, created, **kwargs):
    if sender not in [Category]:
        return
    if created:
        # some operations with 'name_ru' 'name_en' fields (since django-modeltranslation)
        instance.save(update_fields=['name'])

引发“节点不得成为其任何后代的子节点”

node        <Category: Obj3>
right       3L
target      <Category: Obj2>
level       1L
self        <mptt.managers.TreeManager object at 0x108a76d10>
width       2L
new_tree_id 2L
tree_id     2L
position    u'last-child'
left        2L

当我从这个post_save处理程序中排除类别模型时-一切正常

Django==1.8.2
django-mptt==0.7.4

任何想法或解决办法..。

Answer 1

def move_to(self，target，position='first-child')：“”使用此模型实例调用TreeManager.move\_node的方便方法。注意:这是一种低级方法；它不尊重MPTTMeta.order\_insertion\_by。在大多数情况下，您应该通过设置node.parent来自己移动节点。“

if instance.parent:
    instance.move_to(instance.parent)
instance.save(update_fields=updated_field_list)