| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // ignore_for_file: use_late_for_private_fields_and_variables |
| |
| import 'dart:async'; |
| |
| import 'package:flutter/material.dart'; |
| import 'package:go_router/go_router.dart'; |
| |
| import 'shared/data.dart'; |
| |
| void main() => runApp(App()); |
| |
| /// The main app. |
| class App extends StatelessWidget { |
| /// Creates a [App]. |
| App({Key? key}) : super(key: key); |
| |
| /// The title of the app. |
| static const String title = 'GoRouter Example: Async Data'; |
| |
| /// Repository to query data from. |
| static final Repository repo = Repository(); |
| |
| @override |
| Widget build(BuildContext context) => MaterialApp.router( |
| routeInformationProvider: _router.routeInformationProvider, |
| routeInformationParser: _router.routeInformationParser, |
| routerDelegate: _router.routerDelegate, |
| title: title, |
| ); |
| |
| late final GoRouter _router = GoRouter( |
| routes: <GoRoute>[ |
| GoRoute( |
| path: '/', |
| builder: (BuildContext context, GoRouterState state) => |
| const HomeScreen(), |
| routes: <GoRoute>[ |
| GoRoute( |
| path: 'family/:fid', |
| builder: (BuildContext context, GoRouterState state) => |
| FamilyScreen( |
| fid: state.params['fid']!, |
| ), |
| routes: <GoRoute>[ |
| GoRoute( |
| path: 'person/:pid', |
| builder: (BuildContext context, GoRouterState state) => |
| PersonScreen( |
| fid: state.params['fid']!, |
| pid: state.params['pid']!, |
| ), |
| ), |
| ], |
| ), |
| ], |
| ), |
| ], |
| ); |
| } |
| |
| /// The home screen. |
| class HomeScreen extends StatefulWidget { |
| /// Creates a [HomeScreen]. |
| const HomeScreen({Key? key}) : super(key: key); |
| |
| @override |
| State<HomeScreen> createState() => _HomeScreenState(); |
| } |
| |
| class _HomeScreenState extends State<HomeScreen> { |
| Future<List<Family>>? _future; |
| |
| @override |
| void initState() { |
| super.initState(); |
| _fetch(); |
| } |
| |
| @override |
| void didUpdateWidget(covariant HomeScreen oldWidget) { |
| super.didUpdateWidget(oldWidget); |
| |
| // refresh cached data |
| _fetch(); |
| } |
| |
| void _fetch() => _future = App.repo.getFamilies(); |
| |
| @override |
| Widget build(BuildContext context) => FutureBuilder<List<Family>>( |
| future: _future, |
| builder: (BuildContext context, AsyncSnapshot<List<Family>> snapshot) { |
| if (snapshot.connectionState == ConnectionState.waiting) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('${App.title}: Loading...')), |
| body: const Center(child: CircularProgressIndicator()), |
| ); |
| } |
| |
| if (snapshot.hasError) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('${App.title}: Error')), |
| body: SnapshotError(snapshot.error!), |
| ); |
| } |
| |
| assert(snapshot.hasData); |
| final List<Family> families = snapshot.data!; |
| return Scaffold( |
| appBar: AppBar( |
| title: Text('${App.title}: ${families.length} families'), |
| ), |
| body: ListView( |
| children: <Widget>[ |
| for (final Family f in families) |
| ListTile( |
| title: Text(f.name), |
| onTap: () => context.go('/family/${f.id}'), |
| ) |
| ], |
| ), |
| ); |
| }, |
| ); |
| } |
| |
| /// The family screen. |
| class FamilyScreen extends StatefulWidget { |
| /// Creates a [FamilyScreen]. |
| const FamilyScreen({required this.fid, Key? key}) : super(key: key); |
| |
| /// The id of the family. |
| final String fid; |
| |
| @override |
| State<FamilyScreen> createState() => _FamilyScreenState(); |
| } |
| |
| class _FamilyScreenState extends State<FamilyScreen> { |
| Future<Family>? _future; |
| |
| @override |
| void initState() { |
| super.initState(); |
| _fetch(); |
| } |
| |
| @override |
| void didUpdateWidget(covariant FamilyScreen oldWidget) { |
| super.didUpdateWidget(oldWidget); |
| |
| // refresh cached data |
| if (oldWidget.fid != widget.fid) { |
| _fetch(); |
| } |
| } |
| |
| void _fetch() => _future = App.repo.getFamily(widget.fid); |
| |
| @override |
| Widget build(BuildContext context) => FutureBuilder<Family>( |
| future: _future, |
| builder: (BuildContext context, AsyncSnapshot<Family> snapshot) { |
| if (snapshot.connectionState == ConnectionState.waiting) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('Loading...')), |
| body: const Center(child: CircularProgressIndicator()), |
| ); |
| } |
| |
| if (snapshot.hasError) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('Error')), |
| body: SnapshotError(snapshot.error!), |
| ); |
| } |
| |
| assert(snapshot.hasData); |
| final Family family = snapshot.data!; |
| return Scaffold( |
| appBar: AppBar(title: Text(family.name)), |
| body: ListView( |
| children: <Widget>[ |
| for (final Person p in family.people) |
| ListTile( |
| title: Text(p.name), |
| onTap: () => context.go( |
| '/family/${family.id}/person/${p.id}', |
| ), |
| ), |
| ], |
| ), |
| ); |
| }, |
| ); |
| } |
| |
| /// The person screen. |
| class PersonScreen extends StatefulWidget { |
| /// Creates a [PersonScreen]. |
| const PersonScreen({required this.fid, required this.pid, Key? key}) |
| : super(key: key); |
| |
| /// The id of family the person is in. |
| final String fid; |
| |
| /// The id of the person. |
| final String pid; |
| |
| @override |
| State<PersonScreen> createState() => _PersonScreenState(); |
| } |
| |
| class _PersonScreenState extends State<PersonScreen> { |
| Future<FamilyPerson>? _future; |
| |
| @override |
| void initState() { |
| super.initState(); |
| _fetch(); |
| } |
| |
| @override |
| void didUpdateWidget(covariant PersonScreen oldWidget) { |
| super.didUpdateWidget(oldWidget); |
| |
| // refresh cached data |
| if (oldWidget.fid != widget.fid || oldWidget.pid != widget.pid) { |
| _fetch(); |
| } |
| } |
| |
| void _fetch() => _future = App.repo.getPerson(widget.fid, widget.pid); |
| |
| @override |
| Widget build(BuildContext context) => FutureBuilder<FamilyPerson>( |
| future: _future, |
| builder: (BuildContext context, AsyncSnapshot<FamilyPerson> snapshot) { |
| if (snapshot.connectionState == ConnectionState.waiting) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('Loading...')), |
| body: const Center(child: CircularProgressIndicator()), |
| ); |
| } |
| |
| if (snapshot.hasError) { |
| return Scaffold( |
| appBar: AppBar(title: const Text('Error')), |
| body: SnapshotError(snapshot.error!), |
| ); |
| } |
| |
| assert(snapshot.hasData); |
| final FamilyPerson famper = snapshot.data!; |
| return Scaffold( |
| appBar: AppBar(title: Text(famper.person.name)), |
| body: Text( |
| '${famper.person.name} ${famper.family.name} is ' |
| '${famper.person.age} years old', |
| ), |
| ); |
| }, |
| ); |
| } |
| |
| /// The Error page. |
| class SnapshotError extends StatelessWidget { |
| /// Creates an error page. |
| SnapshotError(Object error, {Key? key}) |
| : error = error is Exception ? error : Exception(error), |
| super(key: key); |
| |
| /// The error. |
| final Exception error; |
| |
| @override |
| Widget build(BuildContext context) => Center( |
| child: Column( |
| mainAxisAlignment: MainAxisAlignment.center, |
| children: <Widget>[ |
| SelectableText(error.toString()), |
| TextButton( |
| onPressed: () => context.go('/'), |
| child: const Text('Home'), |
| ), |
| ], |
| ), |
| ); |
| } |