I have a small question about Django so I have a custom Registration Form which inherits from "UserCreationForm" and therefore I use "fields" to define the fields I want to display. For this test just ("username", "email",). But when I go to see my form which is displayed "Password" and "Password confirmation" are also present. Wanting to understand, I therefore went to see the UserCreationForm class of django but this one has a Meta class which has fields = ("username"), so I don't really see why I have the passwords which are also present. I'm sorry the explanation is a bit laborious but I would like to understand so if anyone has a little explanation thank you very much.

My custom class:

class CustomSignupForm(UserCreationForm):
class Meta:
    model = CustomUser
    fields = ("username", "email",)

The UserCreationForm of django:

class UserCreationForm(forms.ModelForm):
"""
A form that creates a user, with no privileges, from the given username and
password.
"""

error_messages = {
    "password_mismatch": _("The two password fields didn’t match."),
}
password1 = forms.CharField(
    label=_("Password"),
    strip=False,
    widget=forms.PasswordInput(attrs={"autocomplete": "new-password"}),
    help_text=password_validation.password_validators_help_text_html(),
)
password2 = forms.CharField(
    label=_("Password confirmation"),
    widget=forms.PasswordInput(attrs={"autocomplete": "new-password"}),
    strip=False,
    help_text=_("Enter the same password as before, for verification."),
)

class Meta:
    model = User
    fields = ("username",)
    field_classes = {"username": UsernameField}

def __init__(self, *args, **kwargs):
    super().__init__(*args, **kwargs)
    if self._meta.model.USERNAME_FIELD in self.fields:
        self.fields[self._meta.model.USERNAME_FIELD].widget.attrs[
            "autofocus"
        ] = True

def clean_password2(self):
    password1 = self.cleaned_data.get("password1")
    password2 = self.cleaned_data.get("password2")
    if password1 and password2 and password1 != password2:
        raise ValidationError(
            self.error_messages["password_mismatch"],
            code="password_mismatch",
        )
    return password2

def _post_clean(self):
    super()._post_clean()
    # Validate the password after self.instance is updated with form data
    # by super().
    password = self.cleaned_data.get("password2")
    if password:
        try:
            password_validation.validate_password(password, self.instance)
        except ValidationError as error:
            self.add_error("password2", error)

def save(self, commit=True):
    user = super().save(commit=False)
    user.set_password(self.cleaned_data["password1"])
    if commit:
        user.save()
    return user

Here is what it gives:

Display of my form

CodePudding user response：

The reason this happens is that the password1 and password2 field are defined in the UserCreationForm class. The form fields do not need to be listed in the fields attribute: all field objects in the class are form fields.

A ModelForm will in essence add form field objects to the class, and thus automates that process, but any field object defined in the class is a form field, that is how a simple Form ^[Django-doc] behaves, and a ModelForm is just a subclass of Form.

Based on your comment you want to reorder the fields. You can do so with the .field_order attribute ^[Django-doc]:

class CustomSignupForm(UserCreationForm):
    field_order = ('username', 'email', 'password1', 'password2', 'newsletter')
    
    class Meta:
        model = CustomUser
        fields = ('username', 'email', 'newsletter')