/flutter-setup-declarative-routing

name: flutter-setup-declarative-routing
description: Configure `MaterialApp.router` using a package like `go_router` for advanced URL-based navigation. Use when developing web applications or mobile apps that require specific deep linking and browser history support.
metadata:
  model: models/gemini-3.1-pro-preview
  last_modified: Tue, 21 Apr 2026 21:08:03 GMT

Implementing Routing and Deep Linking

Contents

• [Core Concepts](#core-concepts)
• [Workflow: Initializing the Application and Router](#workflow-initializing-the-application-and-router)
• [Workflow: Configuring Platform Deep Linking](#workflow-configuring-platform-deep-linking)
• [Workflow: Implementing Nested Navigation](#workflow-implementing-nested-navigation)
• [Examples](#examples)

Core Concepts

Use the `go_router` package for declarative routing in Flutter. It provides a robust API for complex routing scenarios, deep linking, and nested navigation.

• **GoRouter**: The central configuration object defining the application's route tree.
• **GoRoute**: A standard route mapping a URL path to a Flutter screen.
• **ShellRoute / StatefulShellRoute**: Wraps child routes in a persistent UI shell (e.g., a `BottomNavigationBar`). `StatefulShellRoute` maintains the state of parallel navigation branches.
• **Path URL Strategy**: Removes the default `#` fragment from web URLs, essential for clean deep linking across platforms.

Workflow: Initializing the Application and Router

Follow this workflow to bootstrap a new Flutter application with `go_router` and configure the root routing mechanism.

Task Progress

• [ ] Create the Flutter application.
• [ ] Add the `go_router` dependency.
• [ ] Configure the URL strategy for web/deep linking.
• [ ] Implement the `GoRouter` configuration.
• [ ] Bind the router to `MaterialApp.router`.

1. Scaffold the Application

Run the following commands to create the app and add the required routing package:

flutter create <app-name>
cd <app-name>
flutter pub add go_router

2. Configure the Router

Define a top-level `GoRouter` instance. Handle authentication or state-based routing using the `redirect` parameter.

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:flutter_web_plugins/url_strategy.dart';

void main() {
  // Use path URL strategy to remove the '#' from web URLs
  usePathUrlStrategy();
  runApp(const MyApp());
}

final GoRouter _router = GoRouter(
  initialLocation: '/',
  routes: [
    GoRoute(
      path: '/',
      builder: (context, state) => const HomeScreen(),
      routes: [
        GoRoute(
          path: 'details/:id',
          builder: (context, state) => DetailsScreen(id: state.pathParameters['id']!),
        ),
      ],
    ),
  ],
  errorBuilder: (context, state) => ErrorScreen(error: state.error),
);

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routerConfig: _router,
      title: 'Routing App',
    );
  }
}

Workflow: Configuring Platform Deep Linking

Configure the native platforms to intercept specific URLs and route them into the Flutter application.

Task Progress

• [ ] Determine target platforms (iOS, Android, or both).
• [ ] Apply conditional configuration for Android (Manifest + Asset Links).
• [ ] Apply conditional configuration for iOS (Plist + Entitlements + AASA).
• [ ] Run validator -> review errors -> fix.

If configuring for Android:

1. **Modify `AndroidManifest.xml`**: Add the intent filter inside the `<activity>` tag for `.MainActivity`.

<intent-filter android:autoVerify="true">
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="http" android:host="yourdomain.com" />
    <data android:scheme="https" />
</intent-filter>

2. **Host `assetlinks.json`**: Serve the following JSON at `https://yourdomain.com/.well-known/assetlinks.json`.

[{
  "relation": ["delegate_permission/common.handle_all_urls"],
  "target": {
    "namespace": "android_app",
    "package_name": "com.yourcompany.yourapp",
    "sha256_cert_fingerprints": ["YOUR_SHA256_FINGERPRINT"]
  }
}]

If configuring for iOS:

1. **Modify `Info.plist`**: Opt-in to Flutter's default deep link handler. *Note: If using a third-party deep linking plugin (e.g., `app_links`), set this to `NO` to prevent conflicts.*

<key>FlutterDeepLinkingEnabled</key>
<true/>

2. **Modify `Runner.entitlements`**: Add the associated domain.

<key>com.apple.developer.associated-domains</key>
<array>
  <string>applinks:yourdomain.com</string>
</array>

3. **Host `apple-app-site-association`**: Serve the following JSON (without a `.json` extension) at `https://yourdomain.com/.well-known/apple-app-site-association`.

{
  "applinks": {
    "apps": [],
    "details": [{
      "appIDs": ["TEAM_ID.com.yourcompany.yourapp"],
      "paths": ["*"],
      "components": [{"/": "/*"}]
    }]
  }
}

Validation Loop

Run validator -> review errors -> fix.

• **Android**: Test using ADB.

  adb shell 'am start -a android.intent.action.VIEW -c android.intent.category.BROWSABLE -d "https://yourdomain.com/details/123"' com.yourcompany.yourapp

• **iOS**: Test using `xcrun` on a booted simulator.

  xcrun simctl openurl booted https://yourdomain.com/details/123

Workflow: Implementing Nested Navigation

Use `StatefulShellRoute` to implement persistent UI shells (like a bottom navigation bar) that maintain the state of their child routes.

Task Progress

• [ ] Define `StatefulShellRoute.indexedStack` in the `GoRouter` configuration.
• [ ] Create `StatefulShellBranch` instances for each navigation tab.
• [ ] Implement the shell widget using `StatefulNavigationShell`.

final Go