from django.contrib import messages class SuccessMessageMixin: """ Add a success message on successful form submission. """ success_message = "" def form_valid(self, form): response = super().form_valid(form) success_message = self.get_success_message(form.cleaned_data) if success_message: messages.success(self.request, success_message) return response def get_success_message(self, cleaned_data): return self.success_message % cleaned_data