Deep Location problem

[csinesz]

Deep Location problem

[slovnicki]

@csinesz thanks for reporting this. From the top of my head, I think it's a problem related to something I was trying to solve yesterday (and thought I solved it, but was aware that solution is not ideal). I will test your example and try to fix this today.

[slovnicki]

I solved it, but it's a tricky use case and I'm not sure (yet) how to solve it better at the moment.

First, I noticed you forgot to put BooksThirdLocation() in Beamer.beamLocations, but that did not affect the nature of issue.

The problem was that both BooksLocation and BooksThirdLocation were compared to current stack of pages, but without any pathParameters. At this state then, they are the same. But, the solution was not just to compare everytime with pathParameters because then BooksLocation can never go to just /books without the id part.

So, I added an attribute called keepPathParametersOnPop (default false) to the BeamPage and then BooksThirdLocation should set it to true. In fact, any location that has pages beyond/after :id/ should set this to true.

I also refactored your BooksThirdLocation a little bit to be simpler. Notice that collection-if is not necessary on last BeamPage because there can not be a situation where :id doesn't exists when we're on books/:id/redeem. Because, what would that be... books//redeem? :)

import 'package:flutter/material.dart';
import 'package:beamer/beamer.dart';

// SCREENS
class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home Screen'),
      ),
      body: Center(
        child: RaisedButton(
          onPressed: () => context.beamTo(BooksLocation()),
          child: Text('Go to books location'),
        ),
      ),
    );
  }
}

const List<Map<String, String>> books = [
  {
    'id': '1',
    'title': 'Stranger in a Strange Land',
    'author': 'Robert A. Heinlein',
  },
  {
    'id': '2',
    'title': 'Foundation',
    'author': 'Isaac Asimov',
  },
  {
    'id': '3',
    'title': 'Fahrenheit 451',
    'author': 'Ray Bradbury',
  },
];

class BooksScreen extends StatelessWidget {
  BooksScreen({this.titleQuery = ''});

  final String titleQuery;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Books'),
      ),
      body: ListView(
        children: books
            .where((book) =>
                book['title'].toLowerCase().contains(titleQuery.toLowerCase()))
            .map((book) => ListTile(
                  title: Text(book['title']),
                  subtitle: Text(book['author']),
                  onTap: () => Beamer.of(context).beamTo(
                    BooksLocation.withParameters(
                      path: {'id': book['id']},
                    ),
                  ),
                ))
            .toList(),
      ),
    );
  }
}

class BookDetailsScreen extends StatelessWidget {
  BookDetailsScreen({
    this.book,
  });

  final Map<String, String> book;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(book['title']),
      ),
      body: Column(
        children: [
          Text('Author: ${book['author']}'),
          SizedBox(
            height: 50.0,
          ),
          ElevatedButton(
            child: Text('GO DEEPER -> '),
            onPressed: () {
              Beamer.of(context).beamTo(
                BooksThirdLocation.withParameters(
                  path: {'id': book['id']},
                ),
              );
            },
          ),
        ],
      ),
    );
  }
}

class BookThirdScreen extends StatelessWidget {
  BookThirdScreen({
    this.book,
  });

  final Map<String, String> book;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(book['title']),
      ),
      body: Text('Third screen of book nr. ${book['author']}'),
    );
  }
}

// LOCATIONS
class HomeLocation extends BeamLocation {
  @override
  List<BeamPage> get pages => [
        BeamPage(
          key: ValueKey('home'),
          page: HomeScreen(),
        ),
      ];

  @override
  String get pathBlueprint => '/';
}

class BooksLocation extends BeamLocation {
  BooksLocation() : super();

  BooksLocation.withParameters({
    Map<String, String> path,
    Map<String, String> query,
  }) : super.withParameters(path: path, query: query);

  @override
  List<BeamPage> get pages => [
        ...HomeLocation().pages,
        BeamPage(
          key: ValueKey('books-${queryParameters['title'] ?? ''}'),
          page: BooksScreen(
            titleQuery: queryParameters['title'] ?? '',
          ),
        ),
        if (pathParameters.containsKey('id'))
          BeamPage(
            key: ValueKey('book-${pathParameters['id']}'),
            page: BookDetailsScreen(
              book: books
                  .firstWhere((book) => book['id'] == pathParameters['id']),
            ),
          ),
      ];

  @override
  String get pathBlueprint => '/books/:id';
}

class BooksThirdLocation extends BeamLocation {
  BooksThirdLocation() : super();

  BooksThirdLocation.withParameters({
    Map<String, String> path,
    Map<String, String> query,
  }) : super.withParameters(path: path, query: query);

  @override
  List<BeamPage> get pages => [
        ...BooksLocation.withParameters(
          path: pathParameters,
          query: queryParameters,
        ).pages,
        BeamPage(
          key: ValueKey('book-deeper-${pathParameters['id']}'),
          keepPathParametersOnPop: true,
          page: BookThirdScreen(
            book:
                books.firstWhere((book) => book['id'] == pathParameters['id']),
          ),
        ),
      ];

  @override
  String get pathBlueprint => '/books/:id/deeper';
}

// APP
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Beamer(
      initialLocation: HomeLocation(),
      beamLocations: [
        HomeLocation(),
        BooksLocation(),
        BooksThirdLocation(),
      ],
      notFoundPage: Scaffold(body: Center(child: Text('Not found'))),
      app: MaterialApp(),
    );
  }
}

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

Let me know of any other issues you may encounter.