Navigator.pop(context); shows RangeError (index): Index out of range: index must not be negative: -1

[sivaram16]

Describe the bug
When using Navigator.pop(context) in the latest version of beamer(1.0.0), It throws the error Navigator.pop(context); shows RangeError (index): Index out of range: index must not be negative: -1. This problem happens when using context.beamTo instead of context.beamToNamed.

Beamer version: (v1.0.0)

To Reproduce
Steps to reproduce the behavior:

1. In the location builder example of this plugin location_builder_example.
2. Change context.beamToNamed to context.beamTo.

          context.beamTo(
                 BooksLocation()
                   ..state = BeamState(
                     pathPatternSegments: [
                       'books',
                       ':bookId',
                     ],
                     pathParameters: {"bookId": book['id'].toString()},
                   ),
               ),

3. Try hitting the back button of the book description screen.
4. You can find the above-mentioned error.

Expected behavior
To go back to previous screen instead of the error.

Desktop (please complete the following information):

• OS: Windows 11
• Browser: Chrome

Additional context
Flutter version: 2.5.3

[slovnicki]

Hey @ThalapathySiva 👋
Thanks for creating an issue and providing clear steps how to reproduce.

I was able to reproduce it and make a fix in e47ddf7.

I would suggest using the super constructor to handle the creation of new state for YourBeamLocation. And in this specific use case, it would be better to update the state on currentBeamLocation instead of creating a new one.

[sivaram16]

@slovnicki Thanks for your fix and suggestions and when can I expect this fix in the release?

[slovnicki]

@ThalapathySiva The v1.1.0 release is planned somewhere within next few days, when other linked issues and PRs are resolved. You can inspect the goals and progres for v1.1 milestone here: https://github.com/slovnicki/beamer/milestone/16

Edit: it's published.

[sivaram16]

@slovnicki Yes I have checked and It worked and I have another doubt to ask,

In the same location builder example, you have book and book details screen in same location(BookLocation). But when you have a separate location for the book details screen as I mentioned below, If you navigate to details screen and you hit the back button pop does not work, but browser back button will work just fine.

class BooksLocation extends BeamLocation<BeamState> {
  BooksLocation({RouteInformation? routeInformation}) : super(routeInformation);

  @override
  List<String> get pathPatterns => [
        '/',
        '/books',
      ];

  @override
  List<BeamPage> buildPages(BuildContext context, BeamState state) {
    return [
      BeamPage(
        key: ValueKey('home'),
        title: 'Home',
        child: HomeScreen(),
      ),
      if (state.uri.pathSegments.contains('books'))
        BeamPage(
          key: ValueKey('books'),
          title: 'Books',
          child: BooksScreen(),
        ),
    ];
  }
}

class BooksDetailLocation extends BeamLocation<BeamState> {
  BooksDetailLocation({RouteInformation? routeInformation})
      : super(routeInformation);

  @override
  List<String> get pathPatterns => [
        '/',
        '/books/:bookId',
      ];

  @override
  List<BeamPage> buildPages(BuildContext context, BeamState state) {
    return [
      BeamPage(
        key: ValueKey('book-${state.pathParameters['bookId']}'),
        title: books.firstWhere(
            (book) => book['id'] == state.pathParameters['bookId'])['title'],
        child: BookDetailsScreen(
          book: books.firstWhere(
              (book) => book['id'] == state.pathParameters['bookId']),
        ),
      ),
    ];
  }
}

And Navigate like below,

context.beamTo(
                 BooksDetailLocation()
                        ..state = BeamState(
                          pathPatternSegments: [
                            'books',
                            ':bookId',
                          ],
                          pathParameters: {"bookId": book['id'].toString()},
                        ),
                     );

And finally it would be great if you show me some example to use the super constructor to handle the creation of new state for beam location as you suggested.

[sivaram16]

Hi @slovnicki any update on this ?

[slovnicki]

Hey @ThalapathySiva, sorry for a late response.

This is expected.
AppBar's back button will do a pop and browser's back button will just navigate to last URL. These behaviors are different.

The list of pages you return in buildPages are the pages that the Navigator will stack on top of each other. If there is a page beneath a certain page, we can pop. In the case of your BookDetailLocation, you have just one page in the navigator stack so it cannot pop.

You can read more about this in the Navigating Back section of README. Browser's back button is "reverse chronological", I should probably mention that in README.

[sivaram16]

Can you please let me know the correct way of doing beamTo to particular location along with parameters like I have done above. @slovnicki

[slovnicki]

@ThalapathySiva It depends on what you want.
I have described in my above comment the difference between various back navigations.

The most natural way would be to have all books related pages in the same BeamLocation and stacked on top of each other, like in the example

Best is to navigate with, for example beamToNamed('/books/2), but beamTo you provided above should works the same.

[sivaram16]

@slovnicki Thanks for the reply.