Django表单预览 - 在保存之前将用户添加到表单

class RegistrationFormPreview(FormPreview):
    preview_template    = 'workshops/workshop_register_preview.html'
    form_template       = 'workshops/workshop_register_form.html'

    def done(self, request, cleaned_data):
        # Do something with the cleaned_data, then redirect
        # to a "success" page. 
        # data = request.POST.copy()
        # data['user_id'] = u'%s' % (request.user.id)
        # cleaned_data['user'] = u'%s' % (request.user.id)
        #f = self.form(cleaned_data)
        #f = self.form(data)
        #f.user = request.user


        f = self.form(request.POST)
        f.save()

        pdb.set_trace()
        return HttpResponseRedirect('/register/success')
class RegistrationFormPreview(FormPreview):