How can I change a Django form field value before saving?

Question

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


        

Answer 1

See the documentation for the save() method

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 2

Override _clean methods and put your checks in them. You can modify cleaned_data from there.

E.g:

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

Every fields in the form will have a field_name_clean() method created automatically by Django. This method is called when you do form.is_valid().

Answer 3

You will have problems if you need to fill form from POST, change any form field value and render form again. Here is solution for it:

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

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

And then:

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

Answer 4

If you need to do something to the data before saving, just create a function like:

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

All you need is to create a function with the name **clean_***nameofdata* where nameofdata is the name of the field, so if you want to modify password field, you need:

def clean_password(self):

if you need to modify passwordrepeat

def clean_passwordrepeat(self):

So inside there, just encrypt your password and return the encrypted one.

I mean:

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

so when you valid the form, the password would be encrypted.

Answer 5

In Views:

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()

In Forms:

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

But be careful, this does not check is_valid(). If you want to do that, you can instantiate the form with the new values:

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