Question

Django 2.1.2

我几乎成功地将一个复选框添加到了django管理员列表视图中，该列表未链接到基础模型中的字段。相反，我想根据复选框的值更新模型中的字段。

阅读了here个帖子后，它基本上可以正常工作。我的问题是，如果我在表单中覆盖save（），django会在其他地方中断，说“'NoneType'对象没有属性'save'”。

我有一个 TrainingSession （培训课程）模型，其中包含 submitted_date （提交日期）和 accepted_date （接受日期）。以下代码在列表视图中显示一个复选框，如果设置了acceptd_date，则默认为选中；如果未设置Submitted_date，则该复选框为禁用状态。我的计划是，如果选中此复选框，则将接受日期设置为今天：

class TrainingSessionListForm(forms.ModelForm):
    accept = forms.BooleanField(required=False)
    class Meta:
        model = TrainingSession
        fields = '__all__'

    def __init__(self, *args, **kwargs):
        instance = kwargs.get('instance')
        if instance:
            initiallyApproved = instance.accepted_date is not None
            submittedForApproval = instance.submitted_date is not None
            initial = kwargs.get('initial', {})
            initial['accept'] = initiallyApproved
            self.base_fields['accept'].disabled = not submittedForApproval
            kwargs['initial'] = initial
        super(TrainingSessionListForm, self).__init__(*args, **kwargs)

    def save(self, *args, **kwargs):
        instance = kwargs.get('instance')
        if instance:
            accepted = self.cleaned_data['accept']
            if accepted and instance.accepted_date is None:
                instance.accepted_date = datetime.date.today()
        super(TrainingSessionListForm, self).save(*args, **kwargs)


class TrainingSessionAdmin(admin.ModelAdmin):
    list_display = ['course','learner','submitted_date','accepted_date','accept']
    list_editable = ['learner'] #needed so the editable form works
    list_display_links = ['course']

    def get_changelist_form(self, request, **kwargs):
        return TrainingSessionListForm

    def accept(self, obj=None):
        #needed so list_display doesn't complain
        pass

如果在更改值后单击“保存”，则会收到以下回溯：

Django Version: 2.1.2
Python Version: 3.6.7
Installed Applications:
['assessment.apps.AssessmentConfig',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'crispy_forms']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 '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']



Traceback:

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\exception.py" in inner
  34.             response = get_response(request)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in wrapper
  604.                 return self.admin_site.admin_view(view)(*args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\views\decorators\cache.py" in _wrapped_view_func
  44.         response = view_func(request, *args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\sites.py" in inner
  223.             return view(request, *args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapper
  45.         return bound_method(*args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\utils\decorators.py" in _wrapped_view
  142.                     response = view_func(request, *args, **kwargs)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in changelist_view
  1745.                         self.save_model(request, obj, form, change=True)

File "C:\Users\Aaron\AppData\Local\Programs\Python\Python36\lib\site-packages\django\contrib\admin\options.py" in save_model
  1091.         obj.save()

Exception Type: AttributeError at /admin/assessment/trainingsession/
Exception Value: 'NoneType' object has no attribute 'save'

如果我尝试以下两种方法之一，都会得到相同的结果：

def save(self, *args, **kwargs):
    super(TrainingSessionListForm, self).save(*args, **kwargs)

def save(self, *args, **kwargs):
    pass

还要注意：在我的 __ init __ 中，我必须使用 self.base_fields ，因为 self.fields 不存在（我是是新手，所以也许这只是我缺乏理解）。也是 type（self）.__ name __ 是 TrainingSessionForm ，而不是 TrainingSessionListForm ？

自定义django管理员listview可编辑字段的问题

0 个答案: