如何在保存之前更改 Django 表單字段值？

Question

if request.method == 'POST':
    userf = UsersModelForm(request.POST)
    username = userf.data['username']
    password = userf.data['password']
    passwordrepeat = userf.data['passwordrepeat']
    email = userf.data['email']

我試過這個：

    tempSalt = bcrypt.gensalt()
    password = bcrypt.hashpw(password,tempSalt)
    passwordrepeat = bcrypt.hashpw(passwordrepeat,tempSalt)

    userf.data['password'] = password
    userf.data['passwordrepeat'] = passwordrepeat

但我有錯誤。 如何在保存前更改userf.data['password']和userf.data['passwordrepeat'] ？

錯誤：

AttributeError at /register

This QueryDict instance is immutable

Request Method:     POST
Request URL:    http://127.0.0.1:8000/register
Django Version:     1.3.1
Exception Type:     AttributeError
Exception Value:    

This QueryDict instance is immutable

Exception Location:     /usr/local/lib/python2.6/dist-packages/django/http/__init__.py in _assert_mutable, line 359
Python Executable:  /usr/bin/python
Python Version:     2.6.6
Python Path:    

['/home/user1/djangoblog',
 '/usr/lib/python2.6',
 '/usr/lib/python2.6/plat-linux2',
 '/usr/lib/python2.6/lib-tk',
 '/usr/lib/python2.6/lib-old',
 '/usr/lib/python2.6/lib-dynload',
 '/usr/local/lib/python2.6/dist-packages',
 '/usr/lib/python2.6/dist-packages',
 '/usr/lib/python2.6/dist-packages/gst-0.10',
 '/usr/lib/pymodules/python2.6',
 '/usr/lib/pymodules/python2.6/gtk-2.0']

Answer 1

如果您需要在保存前對數據做一些事情，只需創建一個函數，如：

def clean_nameofdata(self):
    data = self.cleaned_data['nameofdata']
    # do some stuff
    return data

您只需要創建一個名為 **clean_***nameofdata* 的函數，其中nameofdata是字段的名稱，因此如果要修改密碼字段，則需要：

def clean_password(self):

如果需要修改密碼repeat

def clean_passwordrepeat(self):

所以在里面，只需加密您的密碼並返回加密的密碼。

我的意思是：

def clean_password(self):
    data = self.cleaned_data['password']
    # encrypt stuff
    return data

因此，當您驗證表單時，密碼將被加密。

Answer 2

請參閱save()方法的文檔

if request.method == 'POST':
    userf = UsersModelForm(request.POST)
    new_user = userf.save(commit=False)

    username = userf.cleaned_data['username']
    password = userf.cleaned_data['password']
    passwordrepeat = userf.cleaned_data['passwordrepeat']
    email = userf.cleaned_data['email']

    new_user.password = new1
    new_user.passwordrepeat = new2

    new_user.save()

Answer 3

如果您需要從 POST 填寫表單、更改任何表單字段值並再次呈現表單，您將遇到問題。 這是它的解決方案：

class StudentSignUpForm(forms.Form):
  step = forms.IntegerField()

  def set_step(self, step):
    data = self.data.copy()
    data['step'] = step
    self.data = data

接着：

form = StudentSignUpForm(request.POST)
if form.is_valid() and something():
  form.set_step(2)
  return  render_to_string('form.html', {'form': form})

Answer 4

覆蓋_clean方法並將您的檢查放入其中。 您可以從那里修改cleaned_data 。

例如：

def clean_password(self):
    new1 = self.cleaned_data['password']
    return new1

表單中的每個字段都有一個由 Django 自動創建的field_name_clean()方法。 當您執行form.is_valid()時會調用此方法。

Answer 5

在視圖中：

def post(self, request, *args, **kwargs):
    form = self.form_class(request.POST)
    if form.is_valid():
        obj = form.save(commit=False)
        obj.my_field = 'value'
        obj.save()

在表格中：

instance = form.instance
instance.user = request.user
instance.save()

但要小心，這不會檢查is_valid() 。 如果你想這樣做，你可以用新值實例化表單：

# NOT TESTED, NOT SURE IF THIS WORKS...
form = MyForm(instance=instance)
if form.is_valid():
    form.save()