django - 管理模型无法识别继承的字段

Question

我想知道这是否是django.admin，django甚至python特有的东西吗？但是，如果我不能访问它们的字段，我真的不理解拥有抽象父类(super class)的意义:-)。我做错什么了吗？

例子:
如果使用管理界面获取以下模型“Module”，则收到带有以下“异常值:为Module指定的未知字段(creation_date)的FieldError。请检查类ModuleAdmin的field/fieldsets/exclude属性”。

class GeneralModel(models.Model):
    creation_date = models.DateTimeField('date of creation', auto_now_add=True)
    edited_date = models.DateTimeField('date of last modification', auto_now=True)

    class Meta:
        abstract = True


class Module(GeneralModel):
    name = models.CharField(max_length=100)
    shortDescription = models.CharField("summary", max_length=100)
    description = models.CharField("description", max_length=1500)
    authors = models.ManyToManyField("Author", through="Authorship")

    def __unicode__(self):
        return self.name

使用以下ModelAdmin代码:

class ModuleAdmin(admin.ModelAdmin):
    def formfield_for_dbfield(self, db_field, **kwargs):
        formfield = super(ModuleAdmin, self).formfield_for_dbfield(db_field, **kwargs)
        if db_field.name == 'description':
            formfield.widget = forms.Textarea(attrs=formfield.widget.attrs)
        return formfield
    fieldsets = [
        ("General", {"fields": ["name", "shortDescription"]}),
        ("Details", {"fields": ["description", "creation_date"], "classes": ["collapse"]})
    ]

Answer 1

您的问题与答案有关:
https://stackoverflow.com/a/3594927/3006165

The error is due to date having auto_now_add=True (or auto_now=True). As the value is automatic, it's not editable, so it's not in the form

根据文献:

The fields option ... may contain callables only if they are listed in readonly_fields.