fetcher or not fetcher?

[redhat127]

Let’s say I have a /user/:userId route, and within that route, I use a fetcher form to toggle the user’s activity. I use fetcher to prevent navigation.

However, when JavaScript is disabled and I submit the fetcher form, the UI shows the changes as expected, but when I click the back button, the server processes the form submission again. This happens because I didn’t follow the "redirect after POST" rule, so the browser tries to re-submit the form data.

On the other hand, if I do a redirect inside the action, then with JavaScript enabled, the fetcher causes a navigation instead of staying on the same /user/:userId page—which defeats the purpose of using a fetcher.

My proposed solution is to include a hidden input using the useHydrated hook. This input would only be added when JavaScript is enabled. Then, on the backend, I check for the presence of that field in formData:

If it exists (i.e., JS is on), I return null to stay on the same page.

If it doesn’t (i.e., JS is off), I redirect after the form submission to avoid re-submission on back button.

Does this sound like a valid solution, or am I missing something?