表单集数据初始化

Question

我正在尝试理解formset数据的初始化是如何工作的。要创建表单集，您可以使用formset_factory并定义参数" extra“和"max_num"，这两个参数决定了在初始/填写表单之后额外空白表单的数量以及分别发布的表单的最大数量。但是，当您创建已定义表单集的实例以将其作为数据传递给模板时，需要向该实例传递更多数据，特别是'form-TOTAL_FORMS‘、'form-INITIAL_FORMS’和'form-MAX_NUM_FORMS‘。但是我们不是已经在formset_factory中定义了max_num_forms吗？为什么我们要定义两次呢？对于文档来说，初始表单似乎就像它听起来的那样--已经填写的表单，这与“额外”是不同的。只是不理解如何定义两次最大参数。

Answer 1

根据文档：

You may have noticed the additional data (form-TOTAL_FORMS, form-INITIAL_FORMS and form-MAX_NUM_FORMS) that was required in the formset’s data above. This data is required for the ManagementForm. This form is used by the formset to manage the collection of forms contained in the formset. If you don’t provide this management data, an exception will be raised.

https://docs.djangoproject.com/en/2.2/topics/forms/formsets/#understanding-the-managementform