django-mptt - 如何在同一棵树中设置不同的模型

Question

我想要一棵树来模仿带有文件夹和文件的文件系统。文件夹和文件将由具有不同字段属性的不同模型定义。

楷模:

from mptt.models import MPTTModel, TreeForeignKey

class Folder(MPTTModel):
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children')
    name = models.CharField(max_length=50)
    type = models.CharField(max_length=50)

class File(MPTTModel):
    parent= TreeForeignKey(Document)
    filename = models.CharField(max_length=255)
    encoding = models.CharField(max_length=20)
    date_created = models.DateTimeField(auto_now_add=True)
    date_updated = models.DateTimeField(auto_now=True)

创建一些文件夹和文件:

 from shapefile.models import Folder, File
 root = Folder.objects.create(name="Root")
 download = Folder.objects.create(name="Download", parent=root)
 upload = Folder.objects.create(name="Upload", parent=root)
 File.objects.create(filename="Test", encoding="UTF-8", parent=download)

应该有:

> Root
> --Download
> ----Test
> --Upload

如何在 View 和模板中检索这棵树？

编辑:

文件不会作为文件夹的节点插入:

file = File.objects.get(filename="Test")
file.get_ancestors()
>>> []

Answer 1

您可以将 MPTTModel 与 generic relation 结合使用
来自内容类型框架。
您可以通过将 'django.contrib.contenttypes' 添加到您的 INSTALLED_APPS 设置来启用它。

from django.db import models
from mptt.models import MPTTModel, TreeForeignKey

class TreeItem(MPTTModel):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children')

class Folder(models.Model):
    name = models.CharField(max_length=50)
    type = models.CharField(max_length=50)

class File(models.Model):
    filename = models.CharField(max_length=255)
    encoding = models.CharField(max_length=20)
    date_created = models.DateTimeField(auto_now_add=True)
    date_updated = models.DateTimeField(auto_now=True)

mptt documentacion解释了如何访问模板中的树。