Question

我有一个django表单，我想自定义清理。我不想仅仅像这里一样指定错误消息（Django form and field validation），而是想自己改变字段。我尝试了一些方法，但一直遇到错误，就像cleaning_data是不可变的一样。

所以为了解决这个问题，我制作了一份副本，更改了它并将其重新分配给了自己。这是最好的方法吗？可以/我应该在视图中处理这个吗？制作副本似乎很糟糕，但我一直遇到“不可变”的障碍。下面的示例代码我只是检查主题是否在末尾有'--help'，如果没有添加它。感谢

def clean(self):
        cleaned_data=self.cleaned_data.copy()
        subject=cleaned_data.get['subject']
        if not subject.endswith('--help'):
            cleaned_data['subject']=subject+='--help'
        self.cleaned_data=cleaned_data
        return self.cleaned_data

Answer 1

处理此问题的正确方法是使用字段特定的清理方法。

从clean_FOO方法返回的内容是cleaned_data在到达clean函数时将填充的内容。

请执行以下操作：

def clean_subject(self):
        data = self.cleaned_data.get('subject', '')
        if not data:
             raise forms.ValidationError("You must enter a subject")
             # if you don't want this functionality, just remove it.

        if not data.endswith('--help'):
             return data += '--help'
        return data

Answer 2

So, I found this recently having googled about possibly the same problem, whereby in a ModelForm instance of a form, I was trying to edit the data post-validation to provide a suggestion for the end user as to something that would be a valid response (computed from another value they enter into the form).

The TL:DR; is that if you are dealing with a ModelForm descendent specifically, there are two things that are important:

That you must call super(YourModelFormClass, self).clean() so that unique fields are checked.

That (most relevant to this question) that if you are editing cleaned_data, you must also edit the same field on the instance of your model which is attached to your ModelForm:

def clean(self)
  self.cleaned_data = super(MyModelFormClass, self).clean()
  self.cleaned_data['name']='My suggested value'
  self.instance.name = 'My suggested value'
  return self.cleaned_data

Documentation source for this behaviour

EDIT:

Contrary to the documentation, I have just found that this does not work. you have to edit the form's self.data in order to get the changes to show up when the form displays.

Answer 3

我认为您的问题是您已调用self.cleaned_data.get['subject']，然后将其用作数组。

我有一个消息传递应用程序的代码，用“无主题”替换空主题

def clean(self):
    super(forms.ModelForm, self).clean()
    subject = self.cleaned_data['subject']
    if subject.isspace():
        self.cleaned_data['subject'] = 'No Subject'
    return self.cleaned_data

对于您的代码，这应该有用。

def clean(self):
    super(forms.Form, self).clean() #I would always do this for forms.
    subject = self.cleaned_data['subject']
    if not subject.endswith('--help'):
        subject += '--help'
        self.cleaned_data['subject'] = subject
    return self.cleaned_data

Answer 4

“此方法应返回从cleaning_data获取的已清理值，无论其是否发生任何变化。”来自https://docs.djangoproject.com/en/dev/ref/forms/validation/

django用干净的方法改变表格数据

4 个答案: