zenrouter

name	zenrouter
description	> Use when this capability is needed.

ZenRouter Skill

This project uses zenrouter — a Flutter router that supports imperative, declarative, and coordinator-based navigation. This skill covers the Coordinator + RouteModule pattern, which is the right choice when you need deep linking, URL sync, layouts, and modular feature organisation.

Deep-dive references — read these only when you need the specific topic:

File	When to read
ADVANCED.md	Coordinator-as-Module, tab navigation, composable redirect rules, parameter route examples
MIXIN.md	Full reference for RouteGuard, RouteRedirect, RouteDeepLink, RouteTransition, RouteQueryParameters, RouteRestorable
NAVIGATION.md	When to use push vs navigate vs replace and other navigation methods

---

Key Types

Type	Package	Purpose
RouteTarget	zenrouter_core	Base class for all routes; identity via props
RouteUnique	zenrouter_core	Mixin — adds URI identity; required for coordinator routes
Coordinator<T>	zenrouter	Central hub: owns NavigationPaths, parses URIs, drives Flutter Router
CoordinatorModular<T>	zenrouter_core	Mixin on Coordinator — splits route parsing across RouteModules
RouteModule<T>	zenrouter_core	Handles one feature's URI patterns and navigation paths
NavigationPath<T>	zenrouter	Mutable stack of routes; one per layout group
IndexedStackPath<T>	zenrouter	Fixed set of routes for tab-bar style navigation
RouteLayout<T>	zenrouter	Mixin — layout route that wraps nested routes (shell, tab bar, drawer, etc.)
RouteRedirectRule<T>	zenrouter_core	Mixin — delegates redirect logic to a list of RedirectRules
RedirectRule<T>	zenrouter_core	Single composable guard; returns continueRedirect, redirectTo, or stop

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1. Route Base Type

All routes in a coordinator must extend RouteTarget with RouteUnique:

abstract class AppRoute extends RouteTarget with RouteUnique {
  @override
  Widget build(covariant Coordinator coordinator, BuildContext context);
}

---

2. Coordinator

Simple (no modules)

class AppCoordinator extends Coordinator<AppRoute> {
  late final homeStack = NavigationPath<AppRoute>.createWith(
    label: 'home',
    coordinator: this,
  )..bindLayout(HomeLayout.new);

  @override
  List<StackPath> get paths => [...super.paths, homeStack];

  @override
  AppRoute parseRouteFromUri(Uri uri) => switch (uri.pathSegments) {
    [] || ['home'] => HomeRoute(),
    ['product', final id] => ProductRoute(id: id),
    _ => NotFoundRoute(uri: uri),
  };
}

// Wire up:
MaterialApp.router(routerConfig: AppCoordinator())

Modular (with feature modules)

Add CoordinatorModular<T> to delegate URI parsing across feature modules:

class AppCoordinator extends Coordinator<AppRoute>
    with CoordinatorModular<AppRoute> {
  @override
  Set<RouteModule<AppRoute>> defineModules() => {
    AuthModule(this),
    ShopModule(this),
    ProfileModule(this),
  };

  @override
  AppRoute notFoundRoute(Uri uri) => NotFoundRoute(uri: uri);
}

Rules:

• Module order in defineModules() determines parsing priority — first non-null result wins.
• CoordinatorModular overrides parseRouteFromUri automatically; do not override it.
• notFoundRoute is called when all modules return null.

For nested feature groups with sub-modules, see Coordinator as Module in ADVANCED.md.

---

3. Route Module

class ShopModule extends RouteModule<AppRoute> {
  ShopModule(super.coordinator);

  late final shopStack = NavigationPath<AppRoute>.createWith(
    coordinator: coordinator,   // ← always the inherited `coordinator` field (= root)
    label: 'shop',
  )..bindLayout(ShopLayout.new);

  @override
  List<StackPath> get paths => [shopStack];

  @override
  FutureOr<AppRoute?> parseRouteFromUri(Uri uri) => switch (uri.pathSegments) {
    ['shop'] => ShopHomeRoute(),
    ['shop', 'products', final id] => ProductDetailRoute(id: id),
    _ => null,   // ← MUST return null for unrecognised URIs
  };
}

Rules:

• Always return null for unrecognised URIs so other modules can claim them.
• Use coordinator (inherited field) for NavigationPath.createWith — it always refers to the root coordinator that owns the navigation state.
• bindLayout(LayoutClass.new) takes the constructor, not an instance.

---

4. Route Definition

// Standard route
class ShopHomeRoute extends AppRoute {
  @override
  Object? get parentLayoutKey => ShopLayout;   // matches RouteLayout.layoutKey (default: runtimeType)

  @override
  Uri toUri() => Uri.parse('/shop');

  @override
  Widget build(covariant AppCoordinator coordinator, BuildContext context) {
    return ShopHomePage(
      onProductTap: (id) => coordinator.push(ProductDetailRoute(id: id)),
    );
  }
}

// Route with parameters — must override props
class ProductDetailRoute extends AppRoute {
  ProductDetailRoute({required this.id});
  final String id;

  @override
  List<Object?> get props => [id];

  @override
  Object? get parentLayoutKey => ShopLayout;

  @override
  Uri toUri() => Uri.parse('/shop/products/$id');

  @override
  Widget build(covariant AppCoordinator coordinator, BuildContext context) =>
      ProductDetailPage(id: id);
}

Rules:

• parentLayoutKey must exactly match layoutKey of the target RouteLayout. Default layoutKey is runtimeType, so using the layout class Type is simplest.
• Override props for routes with parameters.
• toUri() is used for deep linking and URL sync.

For redirect-only routes, see RedirectRule in ADVANCED.md.

---

5. Layout

class ShopLayout extends AppRoute with RouteLayout<AppRoute> {
  @override
  StackPath<AppRoute> resolvePath(covariant AppCoordinator coordinator) =>
      coordinator.getModule<ShopCoordinator>().shopStack;

  // layoutKey defaults to runtimeType — override only if you need a custom value
  // @override Object get layoutKey => 'ShopLayout';

  @override
  Widget build(covariant AppCoordinator coordinator, BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Shop')),
      body: buildPath(coordinator),   // renders the active child route
    );
  }
}

Rules:

• Use buildPath(coordinator) to render child routes — do not call super.build().
• resolvePath must return the exact NavigationPath that was bindLayout-ed in the module.
• For tab navigation, see IndexedStackPath in ADVANCED.md.

---

6. Navigation

coordinator.push(ProductDetailRoute(id: '42'));    // add to stack
coordinator.navigate(ShopHomeRoute());             // pop-to-existing or push new
coordinator.replace(SettingsRoute());              // full state reset
coordinator.pop();                                 // pop top route

// Navigate from a URI string (e.g. deep link):
final route = await coordinator.parseRouteFromUri(Uri.parse('/shop/products/42'));
coordinator.push(route!);

Redirect rules run automatically on every navigation call.

For full details on pushReplacement, pushOrMoveToTop, tryPop, recover, and decision flowcharts, see NAVIGATION.md.

---

7. File Structure Convention

lib/src/router/
├── coordinator.dart          ← Root Coordinator or Coordinator-as-Module
├── route.dart                ← Base route type (e.g. AppRoute)
├── _public.dart              ← Barrel: export module + public routes + public rules
├── rules/
│   ├── auth_required.dart
│   └── force_redirect.dart
└── routes/
    ├── (auth)/               ← Route group (shares a layout)
    │   ├── _layout.dart      ← Layout for this group
    │   ├── sign_in.dart      ← /sign-in
    │   └── forgot_password.dart
    ├── (dashboard)/
    │   ├── _layout.dart
    │   ├── _index.dart       ← Index / redirect-only route
    │   └── transactions/     ← URI segment directory
    │       ├── _index.dart   ← /transactions
    │       └── [id].dart     ← /transactions/:id  (named parameter route)
    │   └── blog/
    │       ├── _layout.dart   ← blog layout
    │       └── [...slug].dart ← /blog/*             (catch-all parameter route)
    └── not_found.dart

Conventions:

• (group)/ — parenthesised directories are layout groups (organisational only). They do not appear in the URI. Routes inside share a layout.
• group/ — bare directories (no parentheses) do appear in the URI. transactions/ → the URI includes /transactions/....
• _layout.dart — the RouteLayout for its group; prefixed with _ because it's structural, not a user-facing route.
• _index.dart — the index route for a directory (often a redirect-only route).
• [param].dart — a named parameter route file. The brackets mirror dynamic URI segments (e.g. [id].dart → /transactions/:id).
• [...param].dart — a catch-all parameter route file. Captures all remaining URI segments as a single list (e.g. [...slug].dart → /blog/*).
• _public.dart — barrel file that exports only public symbols.
• rules/ — reusable RedirectRule implementations.

For detailed examples of parameter route classes, see Named Parameter Routes and Catch-All Parameter Routes in ADVANCED.md.

---

8. Naming Conventions

Route Classes

Pattern	Example	When
<Feature>Route	SignInRoute, TransactionRoute	Standard page route
<Feature>DetailRoute	TransactionDetailRoute	Detail page with [id]
<Feature>IndexRoute	DashboardIndexRoute	Index / redirect-only route
<Feature>Tab	HomeTab, ShopTab	Tab in an IndexedStackPath
NotFoundRoute	NotFoundRoute	404 catch-all

Layout, Module, and Rule Classes

Pattern	Example	When
<Feature>Layout	AuthLayout, DashboardLayout	Layout shell
<Feature>Module	AuthModule, ShopModule	Simple RouteModule
<Feature>Coordinator	ShopCoordinator	Coordinator-as-Module (has sub-modules)
<Condition>Rule	AuthRequiredRule, AlreadyAuthRule	Redirect rule

URI Patterns

Pattern	Example	Route
/feature	/sign-in	SignInRoute
/feature/:id	/transaction/abc123	TransactionDetailRoute(id: 'abc123')
/group/feature	/shop/products	ProductListRoute
/group/feature/:id	/shop/products/42	ProductDetailRoute(id: '42')

Use kebab-case for URI segments. Use singular nouns for resource detail paths (/transaction/:id not /transactions/:id).

NavigationPath labels use kebab-case: 'auth', 'dashboard', 'shop-products'.

---

9. Adding a New Feature: Checklist

1. Create route — extend base route type; set parentLayoutKey, toUri(), build(), props.
2. Register in parseRouteFromUri of the owning module.
3. Export from _public.dart barrel if navigated to from outside.
4. New layout group? — create (group)/_layout.dart with RouteLayout, new NavigationPath with bindLayout, add to paths.
5. New module? — create module.dart extending RouteModule<T>, register in parent's defineModules().
6. New feature group with sub-modules? — use Coordinator-as-Module pattern.

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Common Mistakes

Mistake	Fix
parseRouteFromUri in a module not returning null for non-owned URIs	Must return null so other modules can claim the URI
parentLayoutKey doesn't match layoutKey	Default layoutKey is usually runtimeType — use the layout class Type as parentLayoutKey
Forgetting ...super.paths when overriding paths	Always spread super.paths to include root and inherited module paths
Overriding parseRouteFromUri on a CoordinatorModular coordinator	Don't — CoordinatorModular handles it; override notFoundRoute instead
Standalone Coordinator returning null from parseRouteFromUri	Standalone coordinators must never return null; add a catch-all case

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Source: definev/zenrouter — distributed by TomeVault.