Push route on 404 error builder doesn't work

[jaumard]

I'm trying to do a 404 page not found screen with a button to return to the website:

errorPageBuilder: (BuildContext context, GoRouterState state) {
        return CustomTransitionPage<void>(
          key: state.pageKey,
          transitionsBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
            return FadeTransition(opacity: animation, child: child);
          },
          child: BgContainer(
            child: IntroDialog(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text('404 page introuvable', style: context.textTheme.headline6),
                  const SizedBox(height: kSmallPadding),
                  TextButton(
                    onPressed: () {
                      context.go('/');
                    },
                    child: const Text('Retourner sur le site'),
                  ),
                ],
              ),
            ),
          ),
        );

When I click I get:

======== Exception caught by gesture ===============================================================
The following assertion was thrown while handling a gesture:
Assertion failed: file:///Users/jaumard/.pub-cache/hosted/pub.dartlang.org/go_router-2.2.4/lib/src/go_router.dart:123:12
inherited != null
"No GoRouter found in context"

When the exception was thrown, this was the stack: 
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 251:49  throw_
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 29:3    assertFailed
packages/go_router/src/go_router.dart 123:21                                  of
packages/go_router/go_router.dart 32:25                                       GoRouterHelper.go
packages/heal_happy/common/router.dart 121:31                                 <fn>
packages/flutter/src/material/ink_well.dart 989:21                            [_handleTap]
packages/flutter/src/gestures/recognizer.dart 193:24                          invokeCallback
packages/flutter/src/gestures/tap.dart 608:48                                 handleTapUp
packages/flutter/src/gestures/tap.dart 296:5                                  [_checkUp]
packages/flutter/src/gestures/tap.dart 230:7                                  handlePrimaryPointer
packages/flutter/src/gestures/recognizer.dart 558:9                           handleEvent
packages/flutter/src/gestures/pointer_router.dart 94:12                       [_dispatch]
packages/flutter/src/gestures/pointer_router.dart 139:9                       <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/linked_hash_map.dart 21:13      forEach
packages/flutter/src/gestures/pointer_router.dart 137:17                      [_dispatchEventToRoutes]
packages/flutter/src/gestures/pointer_router.dart 123:7                       route
packages/flutter/src/gestures/binding.dart 440:19                             handleEvent
packages/flutter/src/gestures/binding.dart 420:14                             dispatchEvent
packages/flutter/src/rendering/binding.dart 278:11                            dispatchEvent
packages/flutter/src/gestures/binding.dart 374:7                              [_handlePointerEventImmediately]
packages/flutter/src/gestures/binding.dart 338:5                              handlePointerEvent
packages/flutter/src/gestures/binding.dart 296:7                              [_flushPointerEventQueue]
packages/flutter/src/gestures/binding.dart 279:32                             [_handlePointerDataPacket]
lib/_engine/engine/platform_dispatcher.dart 1018:13                           invoke1
lib/_engine/engine/platform_dispatcher.dart 182:5                             invokeOnPointerDataPacket
lib/_engine/engine/pointer_binding.dart 130:39                                [_onPointerData]
lib/_engine/engine/pointer_binding.dart 555:18                                <fn>
lib/_engine/engine/pointer_binding.dart 508:21                                <fn>
lib/_engine/engine/pointer_binding.dart 216:16                                loggedHandler
Handler: "onTap"
Recognizer: TapGestureRecognizer#a3ce4
  debugOwner: GestureDetector
  state: ready
====================================================================================================

Look like router is not accessible from the context given to the error callback :/ did I miss something ?

I use version 2.2.1 on last flutter stable

[csells]

That's a standard Flutter issue. Assuming the following:

late final router = GoRouter(...);

then you can do the following:

onPressed: () => router.go(...);

Does that work for you?

P.S. don't for the late keyword!

[jaumard]

So I need a global variable to avoid this? It will works for sure but that's ugly :D

[csells]

100% not. You can continue to define your router inside your app, e.g.

class MyApp {
  ...
  late final router = GoRouter(...);
  ...
}

[jaumard]

Yeah I put the router creation inside his own file ^^, something like this:

late GoRouter _router;

GoRouter createRouter(UserStore userStore) => _router = GoRouter(
      //... all routes and redirection stuff
      errorPageBuilder: (BuildContext context, GoRouterState state) {
        return CustomTransitionPage<void>(
          key: state.pageKey,
          transitionsBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
            return FadeTransition(opacity: animation, child: child);
          },
          child: BgContainer(
            child: IntroDialog(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text('404 page introuvable', style: context.textTheme.headline6),
                  const SizedBox(height: kSmallPadding),
                  TextButton(
                    onPressed: () {
                      _router.go('/');
                    },
                    child: const Text('Retourner sur le site'),
                  ),
                ],
              ),
            ),
          ),
        );
      },
    );

I have added the global variable (as private) and no more issues like this.

[csells]

Cool.