django formset bug?

碰到了一个郁闷的问题,修改inlineformset时,全部删掉子表,再新增一行时,报错.

背景: 用django配合jq做动态表格,实现用js动态添加/删除行,并通过inlineformset更新到数据库.示例代码在这里:https://github.com/TommyU/dynamic_form/

重现步骤:

1. 新增一个待办事宜,并设置清单,如下:

2. submit

3. 回头修改(通过列表的update按钮进入),把以上数据全部清空(圈起来的),只留下最后一行空白行,提交.

然后报错了,如下

Environment:

Request Method: POST
Request URL: http://127.0.0.1:8000/todolist/update/14/

Django Version: 1.6.5
Python Version: 2.7.5
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'south',
 'eForm',
 'formset_test')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'django.middleware.locale.LocaleMiddleware')

Traceback:
File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response
  112.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\base.py" in view
  69.             return self.dispatch(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\base.py" in dispatch
  87.         return handler(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\edit.py" in post
  228.         return super(BaseUpdateView, self).post(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django\views\generic\edit.py" in post
  171.             return self.form_valid(form)
File "E:/workspace/django_test/mysite/mysite\formset_test\views.py" in form_valid
  31.         if iter_form.is_valid():
File "C:\Python27\lib\site-packages\django\forms\formsets.py" in is_valid
  292.         err = self.errors
File "C:\Python27\lib\site-packages\django\forms\formsets.py" in errors
  267.             self.full_clean()
File "C:\Python27\lib\site-packages\django\forms\formsets.py" in full_clean
  314.             form = self.forms[i]
File "C:\Python27\lib\site-packages\django\utils\functional.py" in __get__
  49.         res = instance.__dict__[self.func.__name__] = self.func(instance)
File "C:\Python27\lib\site-packages\django\forms\formsets.py" in forms
  133.         forms = [self._construct_form(i) for i in xrange(self.total_form_count())]
File "C:\Python27\lib\site-packages\django\forms\models.py" in _construct_form
  848.         form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs)
File "C:\Python27\lib\site-packages\django\forms\models.py" in _construct_form
  567.                 connection=connections[self.get_queryset().db])
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py" in get_db_prep_lookup
  387.             value = self.get_prep_lookup(lookup_type, value)
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py" in get_prep_lookup
  369.             return self.get_prep_value(value)
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py" in get_prep_value
  613.         return int(value)

Exception Type: ValueError at /todolist/update/14/
Exception Value: invalid literal for int() with base 10: ''

　　

　post数据:

似乎一定要求子表必需有一行数据是原表的?

update对应的python代码如下:

class todo_listUpdateView(UpdateView):
    model = todo_list
    template_name = 'todo_list_create.html'
    success_url = '/todolist/'
    form_class = todo_listForm

    def get_context_data(self, **kwargs):
        context = super(todo_listUpdateView, self).get_context_data(**kwargs)
        if self.request.POST:
            context.update(item_form = todo_itemSet(self.request.POST))
        else:
            context.update(item_form = todo_itemSet(instance =todo_list.objects.get(pk = self.kwargs.get('pk',False))))
        return  context

    def form_valid(self, form):
        iter_form = todo_itemSet(self.request.POST,instance=self.object)
        if iter_form.is_valid():
            self.object = form.save()
            iter_form.instance = self.object
            iter_form.save()
            return HttpResponseRedirect(self.get_success_url())
        else:
            return self.render_to_response(self.get_context_data())

　　

============================经过调试,分析,看文档===================

发现如果用js直接把数据行给remove掉,如果全部move了,会报错.(原因有待分析).

其实,对于inlineformset的更新操作,django有做一个很不错的设计,直接给标志位打标记即可,什么都不用处理.核心修改如下:

1. 从create模板中分离出update模板(因为js处理不同)

2. 将update模板的deleteForm函数修改为:

    function deleteForm(btn, prefix) {
        $(".delete_mark",$(btn).parent().parent()).children().attr("checked","checked")
        $(btn).parents('.item').hide();
        return false;
    }

　同时update模板添加标志位:

<p class="delete_mark">{{form.DELETE}}</p>

　py代码不用修改,就这么简单!(其实django都处理好了,有时间要分析下)

===============备注===================

重现以上bug的方法是将todo_listUpdateView的template_name修改为"todo_list_create.html",如下图所示: