```
## 传递自定义参数到formset表单
有时候您的表单类需要自定义参数，比如 `MyArticleForm` 。您可以在formset实例化的时候传递这个参数:
```
>>> from django.forms import BaseFormSet
>>> from django.forms import formset_factory
>>> from myapp.forms import ArticleForm
>>> class MyArticleForm(ArticleForm):
... def __init__(self, *args, user, **kwargs):
... self.user = user
... super().__init__(*args, **kwargs)
>>> ArticleFormSet = formset_factory(MyArticleForm)
>>> formset = ArticleFormSet(form_kwargs={'user': request.user})
```
`form_kwargs` 也可能依赖于特定的表单实例。formset基类提供了一个 `get_form_kwargs` 方法。该方法只接收一个参数——formset中表单的序列。对于 [empty\_form](#empty-form) ，它的序列是 `None`
```
>>> from django.forms import BaseFormSet
>>> from django.forms import formset_factory
>>> class BaseArticleFormSet(BaseFormSet):
... def get_form_kwargs(self, index):
... kwargs = super().get_form_kwargs(index)
... kwargs['custom_kwarg'] = index
... return kwargs
>>> ArticleFormSet = formset_factory(MyArticleForm, formset=BaseArticleFormSet)
>>> formset = ArticleFormSet()
```
## 自定义formset的前缀
在已渲染的HTML页面中，表单集中的每个字段都包含一个前缀。这个前缀默认是 `'form'` ，但可以使用formset的 `prefix` 参数来自定义。
例如，在默认情况下，您可能会看到:
```html
```
但使用 `ArticleFormset(prefix='article')` 的话就会变为：
```html
```
如果您想 :ref:在视图中使用多个formset \ \` ，这个参数会很有用。
## 在视图和模板中使用formset
Formsets have the following attributes and methods associated with rendering:
#### `BaseFormSet.renderer`
> **New in Django 4.0**
指定 [渲染器](/zh-hans/4.1/ref/forms/renderers/) 用于表单集。默认为 `FORM_RENDER` 配置所指定的渲染器。
#### `BaseFormSet.template_name`
> **New in Django 4.0**
The name of the template rendered if the formset is cast into a string,
e.g. via `print(formset)` or in a template via `{{ formset }}`.
By default, a property returning the value of the renderer's
[`formset_template_name`](/zh-hans/4.1/ref/forms/renderers/#django.forms.renderers.BaseRenderer.formset_template_name). You may
set it as a string template name in order to override that for a particular
formset class.
This template will be used to render the formset's management form, and
then each form in the formset as per the template defined by the form's
[`template_name`](/zh-hans/4.1/ref/forms/api/#django.forms.Form.template_name).
> **Changed in Django 4.1**
>
> In older versions `template_name` defaulted to the string value
> `'django/forms/formset/default.html'`.
#### `BaseFormSet.template_name_div`
> **New in Django 4.1**
The name of the template used when calling [`as_div()`](#django.forms.formsets.BaseFormSet.as_div). By default this
is `"django/forms/formsets/div.html"`. This template renders the
formset's management form and then each form in the formset as per the
form's [`as_div()`](/zh-hans/4.1/ref/forms/api/#django.forms.Form.as_div) method.
#### `BaseFormSet.template_name_p`
> **New in Django 4.0**
The name of the template used when calling [`as_p()`](#django.forms.formsets.BaseFormSet.as_p). By default this
is `"django/forms/formsets/p.html"`. This template renders the formset's
management form and then each form in the formset as per the form's
[`as_p()`](/zh-hans/4.1/ref/forms/api/#django.forms.Form.as_p) method.
#### `BaseFormSet.template_name_table`
> **New in Django 4.0**
The name of the template used when calling [`as_table()`](#django.forms.formsets.BaseFormSet.as_table). By default
this is `"django/forms/formsets/table.html"`. This template renders the
formset's management form and then each form in the formset as per the
form's [`as_table()`](/zh-hans/4.1/ref/forms/api/#django.forms.Form.as_table) method.
#### `BaseFormSet.template_name_ul`
> **New in Django 4.0**
The name of the template used when calling [`as_ul()`](#django.forms.formsets.BaseFormSet.as_ul). By default this
is `"django/forms/formsets/ul.html"`. This template renders the formset's
management form and then each form in the formset as per the form's
[`as_ul()`](/zh-hans/4.1/ref/forms/api/#django.forms.Form.as_ul) method.
#### `BaseFormSet.get_context()`
> **New in Django 4.0**
返回用于在模板中渲染表单集的上下文。
可用的上下文：
- `formset`：表单集的实例。
#### `BaseFormSet.render(template_name=None, context=None, renderer=None)`
> **New in Django 4.0**
The render method is called by `__str__` as well as the [`as_div()`](#django.forms.formsets.BaseFormSet.as_div),
[`as_p()`](#django.forms.formsets.BaseFormSet.as_p), [`as_ul()`](#django.forms.formsets.BaseFormSet.as_ul), and [`as_table()`](#django.forms.formsets.BaseFormSet.as_table) methods. All arguments
are optional and will default to:
- `template_name`： [`template_name`](#django.forms.formsets.BaseFormSet.template_name)
- `context`： 由 [`get_context()`](#django.forms.formsets.BaseFormSet.get_context) 返回的值
- `renderer`： 由 [`renderer`](#django.forms.formsets.BaseFormSet.renderer) 返回的值
#### `BaseFormSet.as_div()`
> **New in Django 4.1**
Renders the formset with the [`template_name_div`](#django.forms.formsets.BaseFormSet.template_name_div) template.
#### `BaseFormSet.as_p()`
用 [`template_name_p`](#django.forms.formsets.BaseFormSet.template_name_p) 模板渲染表单集。
#### `BaseFormSet.as_table()`
使用 [`template_name_table`](#django.forms.formsets.BaseFormSet.template_name_table) 模板渲染表单集。
#### `BaseFormSet.as_ul()`
用 [`template_name_ul`](#django.forms.formsets.BaseFormSet.template_name_ul) 模板渲染表单集。
在视图中使用formset与使用常规的 `Form` 类没有太多不同之处。你唯一需要注意的是确保要在模板中使用管理表单。我们来看一个示例视图：
```
from django.forms import formset_factory
from django.shortcuts import render
from myapp.forms import ArticleForm
def manage_articles(request):
ArticleFormSet = formset_factory(ArticleForm)
if request.method == 'POST':
formset = ArticleFormSet(request.POST, request.FILES)
if formset.is_valid():
# do something with the formset.cleaned_data
pass
else:
formset = ArticleFormSet()
return render(request, 'manage_articles.html', {'formset': formset})
```
模板 `manage_articles.html` 可能如下所示：
```html+django
```
但是对于上面让formset自己处理管理表单，还有个小小的捷径：
```html+django
```
上面的内容最终会调用表单集类上的 [`BaseFormSet.render()`](#django.forms.formsets.BaseFormSet.render) 方法。这将使用 [`template_name`](#django.forms.formsets.BaseFormSet.template_name) 属性指定的模板来渲染表单集。与表单类似，默认情况下，表单集将被渲染为 `as_table`，其他辅助方法 `as_p` 和 `as_ul` 可用。表单集的渲染可以通过指定 `template_name` 属性来定制，或者更普遍的是通过 [覆盖默认模板](/zh-hans/4.1/ref/forms/renderers/#overriding-built-in-formset-templates)。
> **Changed in Django 4.0**
>
> 表单集的渲染被转移到模板引擎。
### 手动渲染 `can_delete` 和 `can_order`
如果您在模板中手动渲染字段，您可以用 `{{ form.DELETE }}` 来渲染参数 `can_delete` 。
```html+django
```
同样，如果formset能排序( `can_order=True` )，可以用 `{{ form.ORDER }}` 来渲染它。
### 在视图中使用多个formset
你可以在视图中使用多个formset。表单集从表单上借鉴了很多行为。像之前说的，你可以使用参数 `prefix` 来给formset中表单的字段附上前缀，以避免多个formset的数据传到同一个视图而引起名称冲突。让我们来看下这是如何实现的：
```
from django.forms import formset_factory
from django.shortcuts import render
from myapp.forms import ArticleForm, BookForm
def manage_articles(request):
ArticleFormSet = formset_factory(ArticleForm)
BookFormSet = formset_factory(BookForm)
if request.method == 'POST':
article_formset = ArticleFormSet(request.POST, request.FILES, prefix='articles')
book_formset = BookFormSet(request.POST, request.FILES, prefix='books')
if article_formset.is_valid() and book_formset.is_valid():
# do something with the cleaned_data on the formsets.
pass
else:
article_formset = ArticleFormSet(prefix='articles')
book_formset = BookFormSet(prefix='books')
return render(request, 'manage_articles.html', {
'article_formset': article_formset,
'book_formset': book_formset,
})
```
然后您就可以像平时那样渲染表单集。需要指出的是，您需要同时在POST和非POST情况下传递 `prefix` ，以便它能被正确渲染和处理。
每个formset的 [prefix](#formset-prefix) 会替换添加到每个字段的 `name` 和 `id` HTML属性的默认 `form` 前缀。