[go_router_builder] Proposal: add json support, custom string encoder/decoder (#8665)

Add initial json support for use in go_router_builder
Adds annotation that enable custom string encoder/decoder, its enable conversion for base64

This allow custom type conversion for parameters, like mentionated in [#117261](flutter/flutter#117261) and [#110781](flutter/flutter#110781)

Author: NearTox

AUTHORS

@@ -80,3 +80,4 @@ LinXunFeng <[email protected]>
 Hashir Shoaib <[email protected]>
 Ricardo Dalarme <[email protected]>
 Andrei Kabylin <[email protected]>
+Ernesto Ramirez <[email protected]>

packages/go_router_builder/CHANGELOG.md

@@ -1,6 +1,11 @@
+## 4.1.0
+
+- Adds support for classes that support fromJson/toJson. [#117261](https://github.com/flutter/flutter/issues/117261)
+- Adds annotation that enable custom string encoder/decoder [#110781](https://github.com/flutter/flutter/issues/110781)
+
 ## 4.0.1
 
-- Fixes unnecessary whitespace in generated `RelativeGoRouteData`. 
+- Fixes unnecessary whitespace in generated `RelativeGoRouteData`.
 
 ## 4.0.0
 

packages/go_router_builder/example/lib/custom_encoder_example.dart

@@ -0,0 +1,94 @@
+// 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: public_member_api_docs, unreachable_from_main
+
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+part 'custom_encoder_example.g.dart';
+
+void main() => runApp(App());
+
+class App extends StatelessWidget {
+  App({super.key});
+
+  @override
+  Widget build(BuildContext context) =>
+      MaterialApp.router(routerConfig: _router, title: _appTitle);
+
+  final GoRouter _router = GoRouter(routes: $appRoutes);
+}
+
+@TypedGoRoute<HomeRoute>(
+  path: '/',
+  name: 'Home',
+  routes: <TypedGoRoute<GoRouteData>>[
+    TypedGoRoute<EncodedRoute>(path: 'encoded'),
+  ],
+)
+class HomeRoute extends GoRouteData with $HomeRoute {
+  const HomeRoute();
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) => const HomeScreen();
+}
+
+class EncodedRoute extends GoRouteData with $EncodedRoute {
+  const EncodedRoute(this.token);
+
+  @CustomParameterCodec(encode: toBase64, decode: fromBase64)
+  final String token;
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) =>
+      EncodedScreen(token: token);
+}
+
+class HomeScreen extends StatelessWidget {
+  const HomeScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(title: const Text(_appTitle)),
+    body: ListView(
+      children: <Widget>[
+        ListTile(
+          title: const Text('Base64Token'),
+          onTap: () => const EncodedRoute('Base64Token').go(context),
+        ),
+        ListTile(
+          title: const Text('from url only'),
+          // like in deep links
+          onTap: () => context.go('/encoded?token=ZW5jb2RlZCBpbmZvIQ'),
+        ),
+      ],
+    ),
+  );
+}
+
+class EncodedScreen extends StatelessWidget {
+  const EncodedScreen({super.key, required this.token});
+  final String token;
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(title: const Text('Base64Token')),
+    body: Center(child: Text(token)),
+  );
+}
+
+String fromBase64(String value) {
+  return const Utf8Decoder().convert(
+    base64Url.decode(base64Url.normalize(value)),
+  );
+}
+
+String toBase64(String value) {
+  return base64Url.encode(const Utf8Encoder().convert(value));
+}
+
+const String _appTitle = 'GoRouter Example: custom encoder';

packages/go_router_builder/example/lib/custom_encoder_example.g.dart

@@ -0,0 +1,82 @@
+// 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: public_member_api_docs, unreachable_from_main
+
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+import 'shared/json_example.dart';
+
+part 'json_example.g.dart';
+
+void main() => runApp(App());
+
+class App extends StatelessWidget {
+  App({super.key});
+
+  @override
+  Widget build(BuildContext context) =>
+      MaterialApp.router(routerConfig: _router, title: _appTitle);
+
+  final GoRouter _router = GoRouter(routes: $appRoutes);
+}
+
+@TypedGoRoute<HomeRoute>(
+  path: '/',
+  name: 'Home',
+  routes: <TypedGoRoute<GoRouteData>>[TypedGoRoute<JsonRoute>(path: 'json')],
+)
+class HomeRoute extends GoRouteData with $HomeRoute {
+  const HomeRoute();
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) => const HomeScreen();
+}
+
+class JsonRoute extends GoRouteData with $JsonRoute {
+  const JsonRoute(this.json);
+
+  final JsonExample json;
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) =>
+      JsonScreen(json: json);
+}
+
+class HomeScreen extends StatelessWidget {
+  const HomeScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(title: const Text(_appTitle)),
+    body: ListView(
+      children: <Widget>[
+        for (final JsonExample json in jsonData)
+          ListTile(
+            title: Text(json.name),
+            onTap: () => JsonRoute(json).go(context),
+          ),
+      ],
+    ),
+  );
+}
+
+class JsonScreen extends StatelessWidget {
+  const JsonScreen({required this.json, super.key});
+  final JsonExample json;
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(title: Text(json.name)),
+    body: ListView(
+      key: ValueKey<String>(json.id),
+      children: <Widget>[Text(json.id), Text(json.name)],
+    ),
+  );
+}
+
+const String _appTitle = 'GoRouter Example: builder';