packages/go_router/lib/src/matching.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 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';

 import 'configuration.dart';
 import 'match.dart';
 import 'path_utils.dart';

 /// Converts a location into a list of [RouteMatch] objects.
 class RouteMatcher {
   /// [RouteMatcher] constructor.
   RouteMatcher(this.configuration);

   /// The route configuration.
   final RouteConfiguration configuration;

   /// Finds the routes that matched the given URL.
   RouteMatchList findMatch(String location, {Object? extra}) {
     final Uri uri = Uri.parse(canonicalUri(location));

     final Map<String, String> pathParameters = <String, String>{};
     final List<RouteMatch> matches =
         _getLocRouteMatches(uri, extra, pathParameters);
     return RouteMatchList(
         matches: matches, uri: uri, pathParameters: pathParameters);
   }

   List<RouteMatch> _getLocRouteMatches(
       Uri uri, Object? extra, Map<String, String> pathParameters) {
     final List<RouteMatch>? result = _getLocRouteRecursively(
       location: uri.path,
       remainingLocation: uri.path,
       routes: configuration.routes,
       matchedLocation: '',
       pathParameters: pathParameters,
       extra: extra,
     );

     if (result == null) {
       throw MatcherError('no routes for location', uri.toString());
     }

     return result;
   }
 }

 /// The list of [RouteMatch] objects.
 ///
 /// This corresponds to the GoRouter's history.
 @immutable
 class RouteMatchList {
   /// RouteMatchList constructor.
   RouteMatchList({
     required this.matches,
     required this.uri,
     required this.pathParameters,
   }) : fullPath = _generateFullPath(matches);

   /// Constructs an empty matches object.
   static RouteMatchList empty = RouteMatchList(
       matches: const <RouteMatch>[],
       uri: Uri(),
       pathParameters: const <String, String>{});

   /// The route matches.
   final List<RouteMatch> matches;

   /// Parameters for the matched route, URI-encoded.
   ///
   /// The parameters only reflects [RouteMatch]s that are not
   /// [ImperativeRouteMatch].
   final Map<String, String> pathParameters;

   /// The uri of the current match.
   ///
   /// This uri only reflects [RouteMatch]s that are not [ImperativeRouteMatch].
   final Uri uri;

   /// the full path pattern that matches the uri.
   ///
   /// For example:
   ///
   /// ```dart
   /// '/family/:fid/person/:pid'
   /// ```
   final String fullPath;

   /// Generates the full path (ex: `'/family/:fid/person/:pid'`) of a list of
   /// [RouteMatch].
   ///
   /// This method ignores [ImperativeRouteMatch]s in the `matches`, as they
   /// don't contribute to the path.
   ///
   /// This methods considers that [matches]'s elements verify the go route
   /// structure given to `GoRouter`. For example, if the routes structure is
   ///
   /// ```dart
   /// GoRoute(
   ///   path: '/a',
   ///   routes: [
   ///     GoRoute(
   ///       path: 'b',
   ///       routes: [
   ///         GoRoute(
   ///           path: 'c',
   ///         ),
   ///       ],
   ///     ),
   ///   ],
   /// ),
   /// ```
   ///
   /// The [matches] must be the in same order of how GoRoutes are matched.
   ///
   /// ```dart
   /// [RouteMatchA(), RouteMatchB(), RouteMatchC()]
   /// ```
   static String _generateFullPath(Iterable<RouteMatch> matches) {
     final StringBuffer buffer = StringBuffer();
     bool addsSlash = false;
     for (final RouteMatch match in matches
         .where((RouteMatch match) => match is! ImperativeRouteMatch)) {
       final RouteBase route = match.route;
       if (route is GoRoute) {
         if (addsSlash) {
           buffer.write('/');
         }
         buffer.write(route.path);
         addsSlash = addsSlash || route.path != '/';
       }
     }
     return buffer.toString();
   }

   /// Returns true if there are no matches.
   bool get isEmpty => matches.isEmpty;

   /// Returns true if there are matches.
   bool get isNotEmpty => matches.isNotEmpty;

   /// Returns a new instance of RouteMatchList with the input `match` pushed
   /// onto the current instance.
   RouteMatchList push<T>(ImperativeRouteMatch<T> match) {
     // Imperative route match doesn't change the uri and path parameters.
     return _copyWith(matches: <RouteMatch>[...matches, match]);
   }

   /// Returns a new instance of RouteMatchList with the input `match` removed
   /// from the current instance.
   RouteMatchList remove(RouteMatch match) {
     final List<RouteMatch> newMatches = matches.toList();
     final int index = newMatches.indexOf(match);
     assert(index != -1);
     newMatches.removeRange(index, newMatches.length);

     // Also pop ShellRoutes when there are no subsequent route matches
     while (newMatches.isNotEmpty && newMatches.last.route is ShellRoute) {
       newMatches.removeLast();
     }
     // Removing ImperativeRouteMatch should not change uri and pathParameters.
     if (match is ImperativeRouteMatch) {
       return _copyWith(matches: newMatches);
     }

     final String fullPath = _generateFullPath(
         newMatches.where((RouteMatch match) => match is! ImperativeRouteMatch));
     // Need to remove path parameters that are no longer in the fullPath.
     final List<String> newParameters = <String>[];
     patternToRegExp(fullPath, newParameters);
     final Set<String> validParameters = newParameters.toSet();
     final Map<String, String> newPathParameters =
         Map<String, String>.fromEntries(
       pathParameters.entries.where((MapEntry<String, String> value) =>
           validParameters.contains(value.key)),
     );
     final Uri newUri =
         uri.replace(path: patternToPath(fullPath, newPathParameters));
     return _copyWith(
       matches: newMatches,
       uri: newUri,
       pathParameters: newPathParameters,
     );
   }

   /// An optional object provided by the app during navigation.
   Object? get extra => matches.isEmpty ? null : matches.last.extra;

   /// The last matching route.
   RouteMatch get last => matches.last;

   /// Returns true if the current match intends to display an error screen.
   bool get isError => matches.length == 1 && matches.first.error != null;

   /// Returns the error that this match intends to display.
   Exception? get error => matches.first.error;

   RouteMatchList _copyWith({
     List<RouteMatch>? matches,
     Uri? uri,
     Map<String, String>? pathParameters,
   }) {
     return RouteMatchList(
         matches: matches ?? this.matches,
         uri: uri ?? this.uri,
         pathParameters: pathParameters ?? this.pathParameters);
   }

   @override
   bool operator ==(Object other) {
     if (other.runtimeType != runtimeType) {
       return false;
     }
     return other is RouteMatchList &&
         const ListEquality<RouteMatch>().equals(matches, other.matches) &&
         uri == other.uri &&
         const MapEquality<String, String>()
             .equals(pathParameters, other.pathParameters);
   }

   @override
   int get hashCode {
     return Object.hash(
       Object.hashAll(matches),
       uri,
       Object.hashAllUnordered(
         pathParameters.entries.map<int>((MapEntry<String, String> entry) =>
             Object.hash(entry.key, entry.value)),
       ),
     );
   }

   @override
   String toString() {
     return '${objectRuntimeType(this, 'RouteMatchList')}($fullPath)';
   }
 }

 /// An error that occurred during matching.
 class MatcherError extends Error {
   /// Constructs a [MatcherError].
   MatcherError(String message, this.location) : message = '$message: $location';

   /// The error message.
   final String message;

   /// The location that failed to match.
   final String location;

   @override
   String toString() {
     return message;
   }
 }

 /// Returns the list of `RouteMatch` corresponding to the given `loc`.
 ///
 /// For example, for a given `loc` `/a/b/c/d`, this function will return the
 /// list of [RouteBase] `[GoRouteA(), GoRouterB(), GoRouteC(), GoRouterD()]`.
 ///
 /// - [location] is the complete URL to match (without the query parameters). For
 ///   example, for the URL `/a/b?c=0`, [location] will be `/a/b`.
 /// - [remainingLocation] is the remaining part of the URL to match while [matchedLocation]
 ///   is the part of the URL that has already been matched. For examples, for
 ///   the URL `/a/b/c/d`, at some point, [remainingLocation] would be `/c/d` and
 ///   [matchedLocation] will be `/a/b`.
 /// - [routes] are the possible [RouteBase] to match to [remainingLocation].
 List<RouteMatch>? _getLocRouteRecursively({
   required String location,
   required String remainingLocation,
   required String matchedLocation,
   required List<RouteBase> routes,
   required Map<String, String> pathParameters,
   required Object? extra,
 }) {
   List<RouteMatch>? result;
   late Map<String, String> subPathParameters;
   // find the set of matches at this level of the tree
   for (final RouteBase route in routes) {
     subPathParameters = <String, String>{};

     final RouteMatch? match = RouteMatch.match(
       route: route,
       remainingLocation: remainingLocation,
       matchedLocation: matchedLocation,
       pathParameters: subPathParameters,
       extra: extra,
     );

     if (match == null) {
       continue;
     }

     if (match.route is GoRoute &&
         match.matchedLocation.toLowerCase() == location.toLowerCase()) {
       // If it is a complete match, then return the matched route
       // NOTE: need a lower case match because matchedLocation is canonicalized to match
       // the path case whereas the location can be of any case and still match
       result = <RouteMatch>[match];
     } else if (route.routes.isEmpty) {
       // If it is partial match but no sub-routes, bail.
       continue;
     } else {
       // Otherwise, recurse
       final String childRestLoc;
       final String newParentSubLoc;
       if (match.route is ShellRoute) {
         childRestLoc = remainingLocation;
         newParentSubLoc = matchedLocation;
       } else {
         assert(location.startsWith(match.matchedLocation));
         assert(remainingLocation.isNotEmpty);

         childRestLoc = location.substring(match.matchedLocation.length +
             (match.matchedLocation == '/' ? 0 : 1));
         newParentSubLoc = match.matchedLocation;
       }

       final List<RouteMatch>? subRouteMatch = _getLocRouteRecursively(
         location: location,
         remainingLocation: childRestLoc,
         matchedLocation: newParentSubLoc,
         routes: route.routes,
         pathParameters: subPathParameters,
         extra: extra,
       );

       // If there's no sub-route matches, there is no match for this location
       if (subRouteMatch == null) {
         continue;
       }
       result = <RouteMatch>[match, ...subRouteMatch];
     }
     // Should only reach here if there is a match.
     break;
   }
   if (result != null) {
     pathParameters.addAll(subPathParameters);
   }
   return result;
 }

 /// The match used when there is an error during parsing.
 RouteMatchList errorScreen(Uri uri, String errorMessage) {
   final Exception error = Exception(errorMessage);
   return RouteMatchList(
     matches: <RouteMatch>[
       RouteMatch(
         matchedLocation: uri.path,
         extra: null,
         error: error,
         route: GoRoute(
           path: uri.toString(),
           pageBuilder: (BuildContext context, GoRouterState state) {
             throw UnimplementedError();
           },
         ),
         pageKey: const ValueKey<String>('error'),
       ),
     ],
     uri: uri,
     pathParameters: const <String, String>{},
   );
 }
	// 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 'package:collection/collection.dart';
	import 'package:flutter/foundation.dart';
	import 'package:flutter/widgets.dart';

	import 'configuration.dart';
	import 'match.dart';
	import 'path_utils.dart';

	/// Converts a location into a list of [RouteMatch] objects.
	class RouteMatcher {
	/// [RouteMatcher] constructor.
	RouteMatcher(this.configuration);

	/// The route configuration.
	final RouteConfiguration configuration;

	/// Finds the routes that matched the given URL.
	RouteMatchList findMatch(String location, {Object? extra}) {
	final Uri uri = Uri.parse(canonicalUri(location));

	final Map<String, String> pathParameters = <String, String>{};
	final List<RouteMatch> matches =
	_getLocRouteMatches(uri, extra, pathParameters);
	return RouteMatchList(
	matches: matches, uri: uri, pathParameters: pathParameters);
	}

	List<RouteMatch> _getLocRouteMatches(
	Uri uri, Object? extra, Map<String, String> pathParameters) {
	final List<RouteMatch>? result = _getLocRouteRecursively(
	location: uri.path,
	remainingLocation: uri.path,
	routes: configuration.routes,
	matchedLocation: '',
	pathParameters: pathParameters,
	extra: extra,
	);

	if (result == null) {
	throw MatcherError('no routes for location', uri.toString());
	}

	return result;
	}
	}

	/// The list of [RouteMatch] objects.
	///
	/// This corresponds to the GoRouter's history.
	@immutable
	class RouteMatchList {
	/// RouteMatchList constructor.
	RouteMatchList({
	required this.matches,
	required this.uri,
	required this.pathParameters,
	}) : fullPath = _generateFullPath(matches);

	/// Constructs an empty matches object.
	static RouteMatchList empty = RouteMatchList(
	matches: const <RouteMatch>[],
	uri: Uri(),
	pathParameters: const <String, String>{});

	/// The route matches.
	final List<RouteMatch> matches;

	/// Parameters for the matched route, URI-encoded.
	///
	/// The parameters only reflects [RouteMatch]s that are not
	/// [ImperativeRouteMatch].
	final Map<String, String> pathParameters;

	/// The uri of the current match.
	///
	/// This uri only reflects [RouteMatch]s that are not [ImperativeRouteMatch].
	final Uri uri;

	/// the full path pattern that matches the uri.
	///
	/// For example:
	///
	/// ```dart
	/// '/family/:fid/person/:pid'
	/// ```
	final String fullPath;

	/// Generates the full path (ex: `'/family/:fid/person/:pid'`) of a list of
	/// [RouteMatch].
	///
	/// This method ignores [ImperativeRouteMatch]s in the `matches`, as they
	/// don't contribute to the path.
	///
	/// This methods considers that [matches]'s elements verify the go route
	/// structure given to `GoRouter`. For example, if the routes structure is
	///
	/// ```dart
	/// GoRoute(
	/// path: '/a',
	/// routes: [
	/// GoRoute(
	/// path: 'b',
	/// routes: [
	/// GoRoute(
	/// path: 'c',
	/// ),
	/// ],
	/// ),
	/// ],
	/// ),
	/// ```
	///
	/// The [matches] must be the in same order of how GoRoutes are matched.
	///
	/// ```dart
	/// [RouteMatchA(), RouteMatchB(), RouteMatchC()]
	/// ```
	static String _generateFullPath(Iterable<RouteMatch> matches) {
	final StringBuffer buffer = StringBuffer();
	bool addsSlash = false;
	for (final RouteMatch match in matches
	.where((RouteMatch match) => match is! ImperativeRouteMatch)) {
	final RouteBase route = match.route;
	if (route is GoRoute) {
	if (addsSlash) {
	buffer.write('/');
	}
	buffer.write(route.path);
	addsSlash = addsSlash \|\| route.path != '/';
	}
	}
	return buffer.toString();
	}

	/// Returns true if there are no matches.
	bool get isEmpty => matches.isEmpty;

	/// Returns true if there are matches.
	bool get isNotEmpty => matches.isNotEmpty;

	/// Returns a new instance of RouteMatchList with the input `match` pushed
	/// onto the current instance.
	RouteMatchList push<T>(ImperativeRouteMatch<T> match) {
	// Imperative route match doesn't change the uri and path parameters.
	return _copyWith(matches: <RouteMatch>[...matches, match]);
	}

	/// Returns a new instance of RouteMatchList with the input `match` removed
	/// from the current instance.
	RouteMatchList remove(RouteMatch match) {
	final List<RouteMatch> newMatches = matches.toList();
	final int index = newMatches.indexOf(match);
	assert(index != -1);
	newMatches.removeRange(index, newMatches.length);

	// Also pop ShellRoutes when there are no subsequent route matches
	while (newMatches.isNotEmpty && newMatches.last.route is ShellRoute) {
	newMatches.removeLast();
	}
	// Removing ImperativeRouteMatch should not change uri and pathParameters.
	if (match is ImperativeRouteMatch) {
	return _copyWith(matches: newMatches);
	}

	final String fullPath = _generateFullPath(
	newMatches.where((RouteMatch match) => match is! ImperativeRouteMatch));
	// Need to remove path parameters that are no longer in the fullPath.
	final List<String> newParameters = <String>[];
	patternToRegExp(fullPath, newParameters);
	final Set<String> validParameters = newParameters.toSet();
	final Map<String, String> newPathParameters =
	Map<String, String>.fromEntries(
	pathParameters.entries.where((MapEntry<String, String> value) =>
	validParameters.contains(value.key)),
	);
	final Uri newUri =
	uri.replace(path: patternToPath(fullPath, newPathParameters));
	return _copyWith(
	matches: newMatches,
	uri: newUri,
	pathParameters: newPathParameters,
	);
	}

	/// An optional object provided by the app during navigation.
	Object? get extra => matches.isEmpty ? null : matches.last.extra;

	/// The last matching route.
	RouteMatch get last => matches.last;

	/// Returns true if the current match intends to display an error screen.
	bool get isError => matches.length == 1 && matches.first.error != null;

	/// Returns the error that this match intends to display.
	Exception? get error => matches.first.error;

	RouteMatchList _copyWith({
	List<RouteMatch>? matches,
	Uri? uri,
	Map<String, String>? pathParameters,
	}) {
	return RouteMatchList(
	matches: matches ?? this.matches,
	uri: uri ?? this.uri,
	pathParameters: pathParameters ?? this.pathParameters);
	}

	@override
	bool operator ==(Object other) {
	if (other.runtimeType != runtimeType) {
	return false;
	}
	return other is RouteMatchList &&
	const ListEquality<RouteMatch>().equals(matches, other.matches) &&
	uri == other.uri &&
	const MapEquality<String, String>()
	.equals(pathParameters, other.pathParameters);
	}

	@override
	int get hashCode {
	return Object.hash(
	Object.hashAll(matches),
	uri,
	Object.hashAllUnordered(
	pathParameters.entries.map<int>((MapEntry<String, String> entry) =>
	Object.hash(entry.key, entry.value)),
	),
	);
	}

	@override
	String toString() {
	return '${objectRuntimeType(this, 'RouteMatchList')}($fullPath)';
	}
	}

	/// An error that occurred during matching.
	class MatcherError extends Error {
	/// Constructs a [MatcherError].
	MatcherError(String message, this.location) : message = '$message: $location';

	/// The error message.
	final String message;

	/// The location that failed to match.
	final String location;

	@override
	String toString() {
	return message;
	}
	}

	/// Returns the list of `RouteMatch` corresponding to the given `loc`.
	///
	/// For example, for a given `loc` `/a/b/c/d`, this function will return the
	/// list of [RouteBase] `[GoRouteA(), GoRouterB(), GoRouteC(), GoRouterD()]`.
	///
	/// - [location] is the complete URL to match (without the query parameters). For
	/// example, for the URL `/a/b?c=0`, [location] will be `/a/b`.
	/// - [remainingLocation] is the remaining part of the URL to match while [matchedLocation]
	/// is the part of the URL that has already been matched. For examples, for
	/// the URL `/a/b/c/d`, at some point, [remainingLocation] would be `/c/d` and
	/// [matchedLocation] will be `/a/b`.
	/// - [routes] are the possible [RouteBase] to match to [remainingLocation].
	List<RouteMatch>? _getLocRouteRecursively({
	required String location,
	required String remainingLocation,
	required String matchedLocation,
	required List<RouteBase> routes,
	required Map<String, String> pathParameters,
	required Object? extra,
	}) {
	List<RouteMatch>? result;
	late Map<String, String> subPathParameters;
	// find the set of matches at this level of the tree
	for (final RouteBase route in routes) {
	subPathParameters = <String, String>{};

	final RouteMatch? match = RouteMatch.match(
	route: route,
	remainingLocation: remainingLocation,
	matchedLocation: matchedLocation,
	pathParameters: subPathParameters,
	extra: extra,
	);

	if (match == null) {
	continue;
	}

	if (match.route is GoRoute &&
	match.matchedLocation.toLowerCase() == location.toLowerCase()) {
	// If it is a complete match, then return the matched route
	// NOTE: need a lower case match because matchedLocation is canonicalized to match
	// the path case whereas the location can be of any case and still match
	result = <RouteMatch>[match];
	} else if (route.routes.isEmpty) {
	// If it is partial match but no sub-routes, bail.
	continue;
	} else {
	// Otherwise, recurse
	final String childRestLoc;
	final String newParentSubLoc;
	if (match.route is ShellRoute) {
	childRestLoc = remainingLocation;
	newParentSubLoc = matchedLocation;
	} else {
	assert(location.startsWith(match.matchedLocation));
	assert(remainingLocation.isNotEmpty);

	childRestLoc = location.substring(match.matchedLocation.length +
	(match.matchedLocation == '/' ? 0 : 1));
	newParentSubLoc = match.matchedLocation;
	}

	final List<RouteMatch>? subRouteMatch = _getLocRouteRecursively(
	location: location,
	remainingLocation: childRestLoc,
	matchedLocation: newParentSubLoc,
	routes: route.routes,
	pathParameters: subPathParameters,
	extra: extra,
	);

	// If there's no sub-route matches, there is no match for this location
	if (subRouteMatch == null) {
	continue;
	}
	result = <RouteMatch>[match, ...subRouteMatch];
	}
	// Should only reach here if there is a match.
	break;
	}
	if (result != null) {
	pathParameters.addAll(subPathParameters);
	}
	return result;
	}

	/// The match used when there is an error during parsing.
	RouteMatchList errorScreen(Uri uri, String errorMessage) {
	final Exception error = Exception(errorMessage);
	return RouteMatchList(
	matches: <RouteMatch>[
	RouteMatch(
	matchedLocation: uri.path,
	extra: null,
	error: error,
	route: GoRoute(
	path: uri.toString(),
	pageBuilder: (BuildContext context, GoRouterState state) {
	throw UnimplementedError();
	},
	),
	pageKey: const ValueKey<String>('error'),
	),
	],
	uri: uri,
	pathParameters: const <String, String>{},
	);
	}