RouteBase class abstract

The base class for GoRoute and ShellRoute.

Routes are defined in a tree such that parent routes must match the current location for their child route to be considered a match. For example the location "/home/user/12" matches with parent route "/home" and child route "user/:userId".

To create sub-routes for a route, provide them as a GoRoute list with the sub routes.

For example these routes:

/         => HomePage()
  family/f1 => FamilyPage('f1')
    person/p2 => PersonPage('f1', 'p2') ← showing this page, Back pops ↑

Can be represented as:

final GoRouter _router = GoRouter(
  routes: <GoRoute>[
    GoRoute(
      path: '/',
      pageBuilder: (BuildContext context, GoRouterState state) => MaterialPage<void>(
        key: state.pageKey,
        child: HomePage(families: Families.data),
      ),
      routes: <GoRoute>[
        GoRoute(
          path: 'family/:fid',
          pageBuilder: (BuildContext context, GoRouterState state) {
            final Family family = Families.family(state.pathParameters['fid']!);
            return MaterialPage<void>(
              key: state.pageKey,
              child: FamilyPage(family: family),
            );
          },
          routes: <GoRoute>[
            GoRoute(
              path: 'person/:pid',
              pageBuilder: (BuildContext context, GoRouterState state) {
                final Family family = Families.family(state.pathParameters['fid']!);
                final Person person = family.person(state.pathParameters['pid']!);
                return MaterialPage<void>(
                  key: state.pageKey,
                  child: PersonPage(family: family, person: person),
                );
              },
            ),
          ],
        ),
      ],
    ),
  ],
);

If there are multiple routes that match the location, the first match is used.
To make predefined routes to take precedence over dynamic routes eg. '/:id'
consider adding the dynamic route at the end of the routes
For example:

final GoRouter router = GoRouter( routes: ) => '/family/${Families.data0.id}', ), GoRoute( path: '/family', pageBuilder: (BuildContext context, GoRouterState state) => ..., ), GoRoute( path: '/:username', pageBuilder: (BuildContext context, GoRouterState state) => ..., ), ], );

In the above example, if /family route is matched, it will be used.
else /:username route will be used.
///
See [main.dart](https://github.com/flutter/packages/blob/main/packages/go_router/example/lib/main.dart)