"Cannot set URL strategy more than once." error using go_router with Flutter Web

Question

I am using go_router flutter package for Flutter Web. I am getting this error while reloading the website. The back button is working great but the reload causes this.

Assertion failed: org-dartlang-sdk:///flutter_web_sdk/lib/_engine/engine/window.dart:25:10 !_isUrlStrategySet "Cannot set URL strategy more than once."

Below is the code for my main.dart:

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:navigator_2/some_app.dart';

import 'details_page.dart';

void main() {
runApp( MyApp());
}


class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
  final GoRouter _router = GoRouter(
    urlPathStrategy: UrlPathStrategy.path,
    routes: [
  GoRoute(path: '/',builder: (context,state)=> const SomeAppPage()),
  GoRoute(path: '/details',builder: (context,state){
    final query = state.queryParams['index'];
    return DetailsPage(index: int.parse(query!));
  }),
]);
return  MaterialApp.router(
  routeInformationParser: _router.routeInformationParser,
    routerDelegate: _router.routerDelegate ,
    title: 'Go Router Example',
    theme: ThemeData(
      primarySwatch: Colors.blue,
    ),
);
 }
 }

Answer 1

The url path strategy to remove the # character from url's should be set in main().

As of go_router 5.1.0, urlPathStrategy has been completely removed, so GoRouter.setUrlPathStrategy(UrlPathStrategy.path); would cause a build error.

In the 5.0 migration guide, instead of GoRouter.setUrlPathStrategy(UrlPathStrategy.path); replace with:

import 'package:flutter_web_plugins/url_strategy.dart';

void main() {
  usePathUrlStrategy();
  runApp(ExampleApp());
}

Answer 2

Divyam Makar's answer didn't work for me because I need to use ChangeNotifier subclass on my GoRouter definition, so when I moved the GoRouter initialisation to initState, I got the exception:

dependOnInheritedWidgetOfExactType<_InheritedProviderScope<MyCustomState?>>() or dependOnInheritedElement() was called before _MainWidgetState.initState() completed.

So, following the documentation, I set the Url Path Strategy in an upper level of the hierarchy, in the main method:

void main() {
  GoRouter.setUrlPathStrategy(UrlPathStrategy.path);
  runApp(App());
}