useNavigation

import { useNavigation } from "@remix-run/react";

function SomeComponent() {
  const navigation = useNavigation();
  // ...
}

// set from either one of these
<Form action="/some/where" />;
submit(formData, { action: "/some/where" });

// set from either one of these
<Form method="get" />;
submit(formData, { method: "get" });

// This form has the `email` field
<Form method="post" action="/signup">
  <input name="email" />
</Form>;

// So a navigation will have the field's value in `navigation.formData`
// while the navigation is pending.
navigation.formData.get("email");