Django 在管理中遇到 generic.GenericTabularInline 问题

Question

我有一个通用的 Django 媒体模型，我想将其与许多其他模型相关联。一切似乎都工作正常，但我无法使用管理中的内联表单保存新的或现有的对象。以下是相关模型：

from django.db import models
from franklin.utils.content_media import *
from django.contrib.contenttypes import generic
from django.contrib.contenttypes.models import ContentType
from franklin.core.scripts.models import Script

class Media(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    media_type = models.CharField(max_length = 20, choices = media_types)
    media_file = models.CharField(max_length = 300, blank = True)
    text_value = models.CharField(max_length = 2000, blank = True)
    caption = models.CharField(max_length = 300, blank = True)
    attributes = models.CharField(max_length = 150, blank = True)
    related_id = models.PositiveIntegerField(null = True, blank = True)
    template = models.ForeignKey(Script, null = True, blank = True)
    sort_order = models.IntegerField(default = 1)

class StaticContent(models.Model):
    title = models.CharField(max_length = 100, unique = True)
    key = models.CharField(max_length = 200, unique = True)
    content_type = models.CharField(max_length = 10, choices = content_types)
    content = models.TextField(blank = True)
    media = generic.GenericRelation(Media, content_type_field='content_type', object_id_field='object_id')

这是管理代码：

from django.contrib import admin
from forms import *
from models import *
from django.contrib.contenttypes import generic

class MediaInline(generic.GenericTabularInline):
    model = Media
    form = MediaFormInline
    extra = 1
    verbose_name_plural = 'media'

class static_content_admin(admin.ModelAdmin):
    inlines = [MediaInline]

admin.site.register(StaticContent, static_content_admin)

这是有问题的表单：

from models import *
from django import forms

class MediaFormInline(forms.ModelForm):

    class Meta:
        model = Media
        fields = ('media_type', 'sort_order',)

内联表单显示正确，但当我保存时出现以下错误：

---

Django 版本：1.3 pre-alpha 异常类型：TypeError 异常值：

“NoneType”对象不可迭代

异常位置：...django\contrib\contenttypes\generic.py in _set_，第 217 行

---

发生错误使用 ReverseGenericRelatedObjectsDescriptor 类的 _set_ 方法。该页面正在向 _set_ 的 value 参数发送 None：

def __set__(self, instance, value):
    if instance is None:
        raise AttributeError("Manager must be accessed via instance")

    manager = self.__get__(instance)
    manager.clear()
    for obj in value:
        manager.add(obj)

任何有关此问题的帮助将不胜感激。如果我不能解决这个问题，我将不得不寻求一个不那么干燥的解决方案。

Answer 1

您需要使用GenericTabularInline。请参阅 Django 文档< /a>.

样本：

from django.contrib.contenttypes.admin import GenericTabularInline


class MediatInline(GenericTabularInline):
    model = Media
    extra = 1


class StaticContentAdmin(admin.ModelAdmin):
    inlines = [MediaInline]