Django formset clean_data为空时提交表单不变

问题描述

关于django 1.4和formsets，我遇到了一个奇怪的问题：当提交的数据不变时，formset的clean_data字段为空，即使表单本身通过验证。

这是一个例子：

forms.py：

  class NameForm（forms.Form）：
 name = forms.CharField（required = False，initial ='Foo'）
  

views.py：

 code> def welcome（request）：
 
 Formset = formset_factory（NameForm，extra = 1）
如果request.method =='POST'：
 formset = Formset （request.POST）
 print'1.Formset有效？'，formset.is_valid（）
 print'2.Formset'，formset 
 print'3.Formset clean_data'，formset。 clean_data 
 else：
 formset = Formset（）
返回render_to_response（'template.html'，localals（））
  

虽然formset是有效的，它实际上包含数据，第3行打印一个空字典的列表，除非我实际上更改了字段中的初始值。

$ b $这对我来说似乎很奇怪，但我可能会做错事？任何帮助？

解决方案

一个表单呈现一堆表单以及几个隐藏的输入字段，其中包含最多数量的表单等信息。因此，正确POST POST的表单始终包含数据。

而且，CharField 名称内的初始Foo是原因那个表单有空字典。当表单的 empty_permitted 设置为True时，表单的所有项目等于其初始值，Django将将表单视为空，并将其clean_data设置为空字符串。 empty_permitted 默认为False，对于额外的表单，formset将设置为True。因此，在您点击提交w / o编辑值Foo后，表单实例被视为空，因此包装表单的表单获得了一个空的clean_data。

I 've been experiencing a weird problem, regarding django 1.4 and formsets: when the submitted data is unchanged, the cleaned_data field of the formset is empty, even if the formset itself passes the validation.

Here is an example:

forms.py:

class NameForm(forms.Form):
    name = forms.CharField(required=False, initial='Foo')

views.py:

def welcome(request):

    Formset = formset_factory(NameForm, extra=1)
    if request.method == 'POST':
        formset = Formset(request.POST)
        print '1.Formset is valid?', formset.is_valid()
        print '2.Formset', formset
        print '3.Formset cleaned_data', formset.cleaned_data
    else:
        formset = Formset()
    return render_to_response('template.html', locals())

Although formset is valid, and it actually contains data, line 3 prints a list of an empty dictionary, unless I 've actually changed the initial value in the field.

This seems weird to me, but I 'm probably doing something wrong? Any help?

解决方案

A formset renders bunch of forms as well as several hidden input fields holding info such as max number of forms. Thus a correctly POSTed formset always contains data.

And, the initial 'Foo' inside CharField name is the reason that formset got empty dictionary. When empty_permitted of a form is set to True, and all items of the form equals to its initial value, Django will treat the form as empty and set its cleaned_data to be empty dict. The empty_permitted defaults to False, formset will set it to True for extra forms. Thus after you clicked submit w/o editing the value 'Foo', the form instance was treated as empty, hence the formset wrapping the form got an empty cleaned_data.

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