packages/go_router/lib/src/go_router_delegate.dart - mirrors/packages - Git at Google

 // 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.

 import 'dart:async';

 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';

 import 'custom_transition_page.dart';
 import 'go_route_information_parser.dart';
 import 'go_route_match.dart';
 import 'go_router_cupertino.dart';
 import 'go_router_error_page.dart';
 import 'go_router_material.dart';
 import 'go_router_state.dart';
 import 'logging.dart';
 import 'route_data.dart';
 import 'typedefs.dart';

 /// GoRouter implementation of the RouterDelegate base class.
 class GoRouterDelegate extends RouterDelegate<List<GoRouteMatch>>
     with PopNavigatorRouterDelegateMixin<List<GoRouteMatch>>, ChangeNotifier {
   /// Constructor for GoRouter's implementation of the
   /// RouterDelegate base class.
   GoRouterDelegate(
     this._parser, {
     required this.builderWithNav,
     required this.errorPageBuilder,
     required this.errorBuilder,
     required this.observers,
     required this.routerNeglect,
     this.restorationScopeId,
   });

   // TODO(chunhtai): remove this once namedLocation is removed from go_router.
   final GoRouteInformationParser _parser;

   /// Builder function for a go router with Navigator.
   final GoRouterBuilderWithNav builderWithNav;

   /// Error page builder for the go router delegate.
   final GoRouterPageBuilder? errorPageBuilder;

   /// Error widget builder for the go router delegate.
   final GoRouterWidgetBuilder? errorBuilder;

   /// NavigatorObserver used to receive change notifications when
   /// navigation changes.
   final List<NavigatorObserver> observers;

   /// Set to true to disable creating history entries on the web.
   final bool routerNeglect;

   /// Restoration ID to save and restore the state of the navigator, including
   /// its history.
   final String? restorationScopeId;

   final GlobalKey<NavigatorState> _key = GlobalKey<NavigatorState>();
   List<GoRouteMatch> _matches = const <GoRouteMatch>[];

   /// Push the given location onto the page stack
   void push(GoRouteMatch match) {
     _matches.add(match);
     notifyListeners();
   }

   /// Pop the top page off the GoRouter's page stack.
   void pop() {
     _matches.remove(_matches.last);
     assert(_matches.isNotEmpty,
         'have popped the last page off of the stack; there are no pages left to show');
     notifyListeners();
   }

   /// For internal use; visible for testing only.
   @visibleForTesting
   List<GoRouteMatch> get matches => _matches;

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   GlobalKey<NavigatorState> get navigatorKey => _key;

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   List<GoRouteMatch> get currentConfiguration => _matches;

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   Widget build(BuildContext context) => _builder(context, _matches);

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   Future<void> setNewRoutePath(List<GoRouteMatch> configuration) {
     _matches = configuration;
     // Use [SynchronousFuture] so that the initial url is processed
     // synchronously and remove unwanted initial animations on deep-linking
     return SynchronousFuture<void>(null);
   }

   Widget _builder(BuildContext context, Iterable<GoRouteMatch> matches) {
     List<Page<dynamic>>? pages;
     Exception? error;
     final String location = matches.last.fullUriString;
     try {
       // build the stack of pages
       if (routerNeglect) {
         Router.neglect(
           context,
           () => pages = getPages(context, matches.toList()).toList(),
         );
       } else {
         pages = getPages(context, matches.toList()).toList();
       }

       // note that we need to catch it this way to get all the info, e.g. the
       // file/line info for an error in an inline function impl, e.g. an inline
       // `redirect` impl
       // ignore: avoid_catches_without_on_clauses
     } catch (err, stack) {
       assert(() {
         log.severe('Exception during GoRouter navigation', err, stack);
         return true;
       }());

       // if there's an error, show an error page
       error = err is Exception ? err : Exception(err);
       final Uri uri = Uri.parse(location);
       pages = <Page<dynamic>>[
         _errorPageBuilder(
           context,
           GoRouterState(
             _parser,
             location: location,
             subloc: uri.path,
             name: null,
             queryParams: uri.queryParameters,
             error: error,
           ),
         ),
       ];
     }

     // we should've set pages to something by now
     assert(pages != null);

     // pass either the match error or the build error along to the navigator
     // builder, preferring the match error
     if (matches.length == 1 && matches.first.error != null) {
       error = matches.first.error;
     }

     // wrap the returned Navigator to enable GoRouter.of(context).go()
     final Uri uri = Uri.parse(location);
     return builderWithNav(
       context,
       GoRouterState(
         _parser,
         location: location,
         name: null, // no name available at the top level
         // trim the query params off the subloc to match route.redirect
         subloc: uri.path,
         // pass along the query params 'cuz that's all we have right now
         queryParams: uri.queryParameters,
         // pass along the error, if there is one
         error: error,
       ),
       Navigator(
         restorationScopeId: restorationScopeId,
         key: _key, // needed to enable Android system Back button
         pages: pages!,
         observers: observers,
         onPopPage: (Route<dynamic> route, dynamic result) {
           if (!route.didPop(result)) {
             return false;
           }
           pop();
           return true;
         },
       ),
     );
   }

   /// Get the stack of sub-routes that matches the location and turn it into a
   /// stack of pages, e.g.
   /// routes: <GoRoute>[
   ///   /
   ///     family/:fid
   ///       person/:pid
   ///   /login
   /// ]
   ///
   /// loc: /
   /// pages: [ HomePage()]
   ///
   /// loc: /login
   /// pages: [ LoginPage() ]
   ///
   /// loc: /family/f2
   /// pages: [ HomePage(), FamilyPage(f2) ]
   ///
   /// loc: /family/f2/person/p1
   /// pages: [ HomePage(), FamilyPage(f2), PersonPage(f2, p1) ]
   @visibleForTesting
   Iterable<Page<dynamic>> getPages(
     BuildContext context,
     List<GoRouteMatch> matches,
   ) sync* {
     assert(matches.isNotEmpty);

     Map<String, String> params = <String, String>{};
     for (final GoRouteMatch match in matches) {
       // merge new params to keep params from previously matched paths, e.g.
       // /family/:fid/person/:pid provides fid and pid to person/:pid
       params = <String, String>{...params, ...match.decodedParams};

       // get a page from the builder and associate it with a sub-location
       final GoRouterState state = GoRouterState(
         _parser,
         location: match.fullUriString,
         subloc: match.subloc,
         name: match.route.name,
         path: match.route.path,
         fullpath: match.fullpath,
         params: params,
         error: match.error,
         queryParams: match.queryParams,
         extra: match.extra,
         pageKey: match.pageKey, // push() remaps the page key for uniqueness
       );
       if (match.error != null) {
         yield _errorPageBuilder(context, state);
         break;
       }

       final GoRouterPageBuilder? pageBuilder = match.route.pageBuilder;
       Page<dynamic>? page;
       if (pageBuilder != null) {
         page = pageBuilder(context, state);
         if (page is NoOpPage) {
           page = null;
         }
       }

       yield page ?? _pageBuilder(context, state, match.route.builder);
     }
   }

   Page<void> Function({
     required LocalKey key,
     required String? name,
     required Object? arguments,
     required String restorationId,
     required Widget child,
   })? _pageBuilderForAppType;

   Widget Function(
     BuildContext context,
     GoRouterState state,
   )? _errorBuilderForAppType;

   void _cacheAppType(BuildContext context) {
     // cache app type-specific page and error builders
     if (_pageBuilderForAppType == null) {
       assert(_errorBuilderForAppType == null);

       // can be null during testing
       final Element? elem = context is Element ? context : null;

       if (elem != null && isMaterialApp(elem)) {
         assert(() {
           log.info('MaterialApp found');
           return true;
         }());
         _pageBuilderForAppType = pageBuilderForMaterialApp;
         _errorBuilderForAppType = (BuildContext c, GoRouterState s) =>
             GoRouterMaterialErrorScreen(s.error);
       } else if (elem != null && isCupertinoApp(elem)) {
         assert(() {
           log.info('CupertinoApp found');
           return true;
         }());
         _pageBuilderForAppType = pageBuilderForCupertinoApp;
         _errorBuilderForAppType = (BuildContext c, GoRouterState s) =>
             GoRouterCupertinoErrorScreen(s.error);
       } else {
         assert(() {
           log.info('WidgetsApp found');
           return true;
         }());
         _pageBuilderForAppType = pageBuilderForWidgetApp;
         _errorBuilderForAppType =
             (BuildContext c, GoRouterState s) => GoRouterErrorScreen(s.error);
       }
     }

     assert(_pageBuilderForAppType != null);
     assert(_errorBuilderForAppType != null);
   }

   // builds the page based on app type, i.e. MaterialApp vs. CupertinoApp
   Page<dynamic> _pageBuilder(
     BuildContext context,
     GoRouterState state,
     GoRouterWidgetBuilder builder,
   ) {
     // build the page based on app type
     _cacheAppType(context);
     return _pageBuilderForAppType!(
       key: state.pageKey,
       name: state.name ?? state.fullpath,
       arguments: <String, String>{...state.params, ...state.queryParams},
       restorationId: state.pageKey.value,
       child: builder(context, state),
     );
   }

   /// Builds a page without any transitions.
   Page<void> pageBuilderForWidgetApp({
     required LocalKey key,
     required String? name,
     required Object? arguments,
     required String restorationId,
     required Widget child,
   }) =>
       NoTransitionPage<void>(
         name: name,
         arguments: arguments,
         key: key,
         restorationId: restorationId,
         child: child,
       );

   Page<void> _errorPageBuilder(
     BuildContext context,
     GoRouterState state,
   ) {
     // if the error page builder is provided, use that; otherwise, if the error
     // builder is provided, wrap that in an app-specific page, e.g.
     // MaterialPage; finally, if nothing is provided, use a default error page
     // wrapped in the app-specific page, e.g.
     // MaterialPage(GoRouterMaterialErrorPage(...))
     _cacheAppType(context);
     return errorPageBuilder != null
         ? errorPageBuilder!(context, state)
         : _pageBuilder(
             context,
             state,
             errorBuilder ?? _errorBuilderForAppType!,
           );
   }
 }
	// 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.

	import 'dart:async';

	import 'package:flutter/foundation.dart';
	import 'package:flutter/widgets.dart';

	import 'custom_transition_page.dart';
	import 'go_route_information_parser.dart';
	import 'go_route_match.dart';
	import 'go_router_cupertino.dart';
	import 'go_router_error_page.dart';
	import 'go_router_material.dart';
	import 'go_router_state.dart';
	import 'logging.dart';
	import 'route_data.dart';
	import 'typedefs.dart';

	/// GoRouter implementation of the RouterDelegate base class.
	class GoRouterDelegate extends RouterDelegate<List<GoRouteMatch>>
	with PopNavigatorRouterDelegateMixin<List<GoRouteMatch>>, ChangeNotifier {
	/// Constructor for GoRouter's implementation of the
	/// RouterDelegate base class.
	GoRouterDelegate(
	this._parser, {
	required this.builderWithNav,
	required this.errorPageBuilder,
	required this.errorBuilder,
	required this.observers,
	required this.routerNeglect,
	this.restorationScopeId,
	});

	// TODO(chunhtai): remove this once namedLocation is removed from go_router.
	final GoRouteInformationParser _parser;

	/// Builder function for a go router with Navigator.
	final GoRouterBuilderWithNav builderWithNav;

	/// Error page builder for the go router delegate.
	final GoRouterPageBuilder? errorPageBuilder;

	/// Error widget builder for the go router delegate.
	final GoRouterWidgetBuilder? errorBuilder;

	/// NavigatorObserver used to receive change notifications when
	/// navigation changes.
	final List<NavigatorObserver> observers;

	/// Set to true to disable creating history entries on the web.
	final bool routerNeglect;

	/// Restoration ID to save and restore the state of the navigator, including
	/// its history.
	final String? restorationScopeId;

	final GlobalKey<NavigatorState> _key = GlobalKey<NavigatorState>();
	List<GoRouteMatch> _matches = const <GoRouteMatch>[];

	/// Push the given location onto the page stack
	void push(GoRouteMatch match) {
	_matches.add(match);
	notifyListeners();
	}

	/// Pop the top page off the GoRouter's page stack.
	void pop() {
	_matches.remove(_matches.last);
	assert(_matches.isNotEmpty,
	'have popped the last page off of the stack; there are no pages left to show');
	notifyListeners();
	}

	/// For internal use; visible for testing only.
	@visibleForTesting
	List<GoRouteMatch> get matches => _matches;

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	GlobalKey<NavigatorState> get navigatorKey => _key;

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	List<GoRouteMatch> get currentConfiguration => _matches;

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	Widget build(BuildContext context) => _builder(context, _matches);

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	Future<void> setNewRoutePath(List<GoRouteMatch> configuration) {
	_matches = configuration;
	// Use [SynchronousFuture] so that the initial url is processed
	// synchronously and remove unwanted initial animations on deep-linking
	return SynchronousFuture<void>(null);
	}

	Widget _builder(BuildContext context, Iterable<GoRouteMatch> matches) {
	List<Page<dynamic>>? pages;
	Exception? error;
	final String location = matches.last.fullUriString;
	try {
	// build the stack of pages
	if (routerNeglect) {
	Router.neglect(
	context,
	() => pages = getPages(context, matches.toList()).toList(),
	);
	} else {
	pages = getPages(context, matches.toList()).toList();
	}

	// note that we need to catch it this way to get all the info, e.g. the
	// file/line info for an error in an inline function impl, e.g. an inline
	// `redirect` impl
	// ignore: avoid_catches_without_on_clauses
	} catch (err, stack) {
	assert(() {
	log.severe('Exception during GoRouter navigation', err, stack);
	return true;
	}());

	// if there's an error, show an error page
	error = err is Exception ? err : Exception(err);
	final Uri uri = Uri.parse(location);
	pages = <Page<dynamic>>[
	_errorPageBuilder(
	context,
	GoRouterState(
	_parser,
	location: location,
	subloc: uri.path,
	name: null,
	queryParams: uri.queryParameters,
	error: error,
	),
	),
	];
	}

	// we should've set pages to something by now
	assert(pages != null);

	// pass either the match error or the build error along to the navigator
	// builder, preferring the match error
	if (matches.length == 1 && matches.first.error != null) {
	error = matches.first.error;
	}

	// wrap the returned Navigator to enable GoRouter.of(context).go()
	final Uri uri = Uri.parse(location);
	return builderWithNav(
	context,
	GoRouterState(
	_parser,
	location: location,
	name: null, // no name available at the top level
	// trim the query params off the subloc to match route.redirect
	subloc: uri.path,
	// pass along the query params 'cuz that's all we have right now
	queryParams: uri.queryParameters,
	// pass along the error, if there is one
	error: error,
	),
	Navigator(
	restorationScopeId: restorationScopeId,
	key: _key, // needed to enable Android system Back button
	pages: pages!,
	observers: observers,
	onPopPage: (Route<dynamic> route, dynamic result) {
	if (!route.didPop(result)) {
	return false;
	}
	pop();
	return true;
	},
	),
	);
	}

	/// Get the stack of sub-routes that matches the location and turn it into a
	/// stack of pages, e.g.
	/// routes: <GoRoute>[
	/// /
	/// family/:fid
	/// person/:pid
	/// /login
	/// ]
	///
	/// loc: /
	/// pages: [ HomePage()]
	///
	/// loc: /login
	/// pages: [ LoginPage() ]
	///
	/// loc: /family/f2
	/// pages: [ HomePage(), FamilyPage(f2) ]
	///
	/// loc: /family/f2/person/p1
	/// pages: [ HomePage(), FamilyPage(f2), PersonPage(f2, p1) ]
	@visibleForTesting
	Iterable<Page<dynamic>> getPages(
	BuildContext context,
	List<GoRouteMatch> matches,
	) sync* {
	assert(matches.isNotEmpty);

	Map<String, String> params = <String, String>{};
	for (final GoRouteMatch match in matches) {
	// merge new params to keep params from previously matched paths, e.g.
	// /family/:fid/person/:pid provides fid and pid to person/:pid
	params = <String, String>{...params, ...match.decodedParams};

	// get a page from the builder and associate it with a sub-location
	final GoRouterState state = GoRouterState(
	_parser,
	location: match.fullUriString,
	subloc: match.subloc,
	name: match.route.name,
	path: match.route.path,
	fullpath: match.fullpath,
	params: params,
	error: match.error,
	queryParams: match.queryParams,
	extra: match.extra,
	pageKey: match.pageKey, // push() remaps the page key for uniqueness
	);
	if (match.error != null) {
	yield _errorPageBuilder(context, state);
	break;
	}

	final GoRouterPageBuilder? pageBuilder = match.route.pageBuilder;
	Page<dynamic>? page;
	if (pageBuilder != null) {
	page = pageBuilder(context, state);
	if (page is NoOpPage) {
	page = null;
	}
	}

	yield page ?? _pageBuilder(context, state, match.route.builder);
	}
	}

	Page<void> Function({
	required LocalKey key,
	required String? name,
	required Object? arguments,
	required String restorationId,
	required Widget child,
	})? _pageBuilderForAppType;

	Widget Function(
	BuildContext context,
	GoRouterState state,
	)? _errorBuilderForAppType;

	void _cacheAppType(BuildContext context) {
	// cache app type-specific page and error builders
	if (_pageBuilderForAppType == null) {
	assert(_errorBuilderForAppType == null);

	// can be null during testing
	final Element? elem = context is Element ? context : null;

	if (elem != null && isMaterialApp(elem)) {
	assert(() {
	log.info('MaterialApp found');
	return true;
	}());
	_pageBuilderForAppType = pageBuilderForMaterialApp;
	_errorBuilderForAppType = (BuildContext c, GoRouterState s) =>
	GoRouterMaterialErrorScreen(s.error);
	} else if (elem != null && isCupertinoApp(elem)) {
	assert(() {
	log.info('CupertinoApp found');
	return true;
	}());
	_pageBuilderForAppType = pageBuilderForCupertinoApp;
	_errorBuilderForAppType = (BuildContext c, GoRouterState s) =>
	GoRouterCupertinoErrorScreen(s.error);
	} else {
	assert(() {
	log.info('WidgetsApp found');
	return true;
	}());
	_pageBuilderForAppType = pageBuilderForWidgetApp;
	_errorBuilderForAppType =
	(BuildContext c, GoRouterState s) => GoRouterErrorScreen(s.error);
	}
	}

	assert(_pageBuilderForAppType != null);
	assert(_errorBuilderForAppType != null);
	}

	// builds the page based on app type, i.e. MaterialApp vs. CupertinoApp
	Page<dynamic> _pageBuilder(
	BuildContext context,
	GoRouterState state,
	GoRouterWidgetBuilder builder,
	) {
	// build the page based on app type
	_cacheAppType(context);
	return _pageBuilderForAppType!(
	key: state.pageKey,
	name: state.name ?? state.fullpath,
	arguments: <String, String>{...state.params, ...state.queryParams},
	restorationId: state.pageKey.value,
	child: builder(context, state),
	);
	}

	/// Builds a page without any transitions.
	Page<void> pageBuilderForWidgetApp({
	required LocalKey key,
	required String? name,
	required Object? arguments,
	required String restorationId,
	required Widget child,
	}) =>
	NoTransitionPage<void>(
	name: name,
	arguments: arguments,
	key: key,
	restorationId: restorationId,
	child: child,
	);

	Page<void> _errorPageBuilder(
	BuildContext context,
	GoRouterState state,
	) {
	// if the error page builder is provided, use that; otherwise, if the error
	// builder is provided, wrap that in an app-specific page, e.g.
	// MaterialPage; finally, if nothing is provided, use a default error page
	// wrapped in the app-specific page, e.g.
	// MaterialPage(GoRouterMaterialErrorPage(...))
	_cacheAppType(context);
	return errorPageBuilder != null
	? errorPageBuilder!(context, state)
	: _pageBuilder(
	context,
	state,
	errorBuilder ?? _errorBuilderForAppType!,
	);
	}
	}