Avoid Flutter App State Reset When Changing Theme with Riverpod and GoRouter

Learn how to prevent Flutter app state reset and unwanted navigation when switching app themes using Riverpod and GoRouter, enabling smooth in-place theme updates without losing current screen.
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This video is based on the question https://stackoverflow.com/q/79349421/ asked by the user 'Mervin Hemaraju' ( https://stackoverflow.com/u/6884119/ ) and on the answer https://stackoverflow.com/a/79350026/ provided by the user 'Ruble' ( https://stackoverflow.com/u/17991131/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Problem Overview

When changing the app theme at runtime in Flutter using Riverpod and GoRouter, the entire app state resets, causing navigation back to the home screen. This interrupts user flow, closing dialogs and settings pages unexpectedly.

Why Does This Happen?

In the provided setup, the router is rebuilt on every widget build with:

[[See Video to Reveal this Text or Code Snippet]]

This means whenever the theme (or any watched state) changes, the entire MesMaterialApp rebuilds, creating a new router starting at the initial route (home or welcome). Consequently, navigation resets.

Key Insight

The router should not be recreated every build based on state that can change dynamically, such as theme or onboarding status.

Solution: Manage Router Independently of Theme Changes

Step 1: Initialize Router Once

Convert the router creation into a separate Provider or Notifier that does not depend on the theme or non-navigation state.

This helps preserve the current location and prevents unintended navigation resets.

For example, create a GoRouter provider:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Use Router Provider in MesMaterialApp

In your app widget, consume this provider without recreating it every build:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Preserve Navigation State

Ensure that the router is not recreated on theme changes by separating router logic from theme-related state.

When theme changes, only the theme mode updates, triggering a theme rebuild but not router reset.

Optional: Use a StateNotifier for Advanced Control

If your app requires dynamic changes to routing based on onboarding or other flags, consider wrapping the router in a StateNotifier (Riverpod's recommended approach).

The notifier updates only when navigation redirects are necessary — not on theme changes.

Summary

Do not recreate router on every build when theme changes.

Separate routing logic from theme and other state changes.

Use providers or notifiers to manage router lifecycle independently.

This approach prevents navigation reset and maintains the current screen and dialog state when changing themes.



By structuring your Flutter app to decouple routing from theming, users can seamlessly switch themes without unexpected navigation changes—delivering a smoother, more native app experience.