python - Django ModelAdmin get_form() 没有设置字段属性

Question

我在我的 ModelAdmin 类中覆盖了 get_form():

def get_form(self, request, obj=None, **kwargs):
    form = super(ModelAdmin, self).get_form(request, obj, **kwargs)

现在，如果我添加这一行:

print form.fields

我得到一个:

AttributeError: type object 'FilerImageForm' has no attribute 'fields'

为什么会这样？调用 super get_form() 是否应该在表单上设置 fields 属性？如果我弄错了，如何访问 ModelAdmin 类中的表单字段？

Answer 1

get_form 返回类而不是实例，fields 属性是实例属性。因此，您必须在访问字段之前实例化表单。

来自 django/contrib/admin/options.py 的定义:

def get_form(self, request, obj=None, **kwargs):
    """
    Returns a Form class for use in the admin add view. This is used by
    add_view and change_view.
    """

更新:

I need to intercept form field creation, not the view. I need to change a field's value, not mess with a template's context. I don't think add_view() is the appropriate place for this.

我认为你可以通过覆盖 formfield_for_dbfield 方法来做到这一点:

def formfield_for_dbfield(self, db_field, **kwargs):
    """
    Hook for specifying the form Field instance for a given database Field
    instance.

    If kwargs are given, they're passed to the form Field's constructor.
    """

    formfield = super(MyModelAdmin, self).formfield_for_dbfield(db_field, **kwargs)

    if db_field.name == "field_you_are_looking_for":
        # change formfield somehow here
        # (or above, by passing modified kwargs in 'super' call)

    return formfield