wtforms Form class subclassing and field ordering

Question

I have a UserForm class:

class UserForm(Form):
    first_name = TextField(u\'First name\', [validators.Required()])
    last_name = TextField(u\'Last name\', [va         


        

Answer 1

In regards to your first question about reording the fields when iterating over the form object, this is what I did:

class BaseForm(Form):
    def __iter__(self):
        field_order = getattr(self, 'field_order', None)
        if field_order:
            temp_fields = []
            for name in field_order:
                if name == '*':
                    temp_fields.extend([f for f in self._unbound_fields if f[0] not in field_order])
                else:
                    temp_fields.append([f for f in self._unbound_fields if f[0] == name][0])
            self._unbound_fields = temp_fields
        return super(BaseForm, self).__iter__()

class BaseUserForm(BaseForm):
    password = PasswordField('Password', [Required()])
    full_name = TextField('Full name', [Required()])

class NewUserForm(BaseUserForm):
    username = Textfield('Username', [Required()])
    field_order = ('username', '*')

That way, when you render NewUserForm (perhaps from a template which iterates over the form rendering field by field), you'll see username, password, full_name. Normally you'd see username last.