如何获取limit_choices_to（Django）中的实体实例？ [英] How to get instance of entity in limit_choices_to (Django)?

问题描述

例如：

class Foo(models.Model):
    bar = models.OneToOneField(
        'app.Bar',
        limit_choices_to=Q(type=1) & Q(foo=None) | Q(foo=instance)
    )


class Bar(models.Model):
    TYPE_CHOICE = (
        (0, 'hello'),
        (1, 'world')
    )
    type = models.SmallIntegerField(
        choices=TYPE_CHOICE,
        default=0
    )

$ b $我想在Django管理中只显示这些具有 type = 1 的这些条，与Foo没有关系，并显示已编辑实体的链接栏（如果是是的）

I wanna show in Django admin only these Bars that have type = 1, that haven't relations with Foo's, and show linked Bar of edited entity (if it is).

当然，我们可以通过覆盖 admin的 formfield_for_foreignkey .ModelAdmin ，但是我们想通过 limit_choices_to 来实现。

Of course, we can do it via overriding formfield_for_foreignkey method of admin.ModelAdmin, but we want do this via limit_choices_to.

如何获取实例的编辑实体？

How to get instance of edited entity?

推荐答案

如果您通过callable to limit_choices_to 引用当前实例。因此，您无法根据当前实例进行过滤。

If you pass a callable to limit_choices_to, that callable has no reference to the current instance. As such, you can't filter based on the current instance either.

还有其他几种方法可以实现所需的功能，例如覆盖 formfield_for_foreignkey（），或者在表单的 __ init __（）方法中覆盖表单域的查询集。 limit_choices_to 只不过是其中之一。

There are several other ways to achieve what you want, such as overriding formfield_for_foreignkey() as you mentioned, or overriding the formfield's queryset in the form's __init__() method. limit_choices_to just isn't one of them.

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