Question

I am writing a change password form, and I would like to pass the original password to the form for validation purposes, but the only way to do that is to make it a hidden field and pass it in with the rest of the data. I obviously don’t want to do that, I’d rather just pass it to the form constructor from within the view, but if it’s not passed in with the formdata then that won’t work.

class MyForm(Form):
    ...
    original_password = HiddenField()
    ...

    def validate_current_password(form, field):
        if field.data != form.original_password.data:
            ERROR

form = MyForm(request.POST, original_password=password) Does not work unless request.POST is empty, or unless I actually render and submit the original password with the form. form.original_password.data is empty otherwise.

Answer 1

For those of you familiar with formencode’s “state” variable, I solved this by subclassing Form and adding a state variable with information to assist in validation.