auto_route 0.2.2

AutoRoute is a route generation library, where everything needed for navigation is automatically generated for you.

auto_route:

AutoRoute is a route generation library, where everything needed for navigation is automatically generated for you.

---

• Installation
• Setup and Usage
• Customization
• Passing Arguments to Routes
• Navigating Using a Global Navigator Key aka Navigating Without Context
• Handling Wrapped Routes
• Nested Navigators
• Custom Route Transitions

Installation

dependencies:
  # add auto_route to your dependencies
  auto_route: [latest-version]

dev_dependencies:
  # add the generator to your dev_dependencies
  auto_route_generator: [latest-version]
  # of course build_runner is needed to run the generator
  build_runner:

Setup and Usage

---

First create a router config class then annotate it with @autoRouter and prefix it's name with $ to get a generated class with the same name minus the $.
$Router => Router

Note: using $ prefix is mandatory.

@autoRouter or @AutoRouter(pass config flags)
class $Router {

}

Now start adding your routes as class fields with the desired route names:

Only use the @MaterialRoute() or @CupertinoRoute() annotations to customize your route

@autoRouter
class $Router {
 // use @initial or @CupertinoRoute(initial: true) to annotate your initial route.
  @initial
  HomeScreen homeScreenRoute; // your desired route name

  SecondScreen secondScreenRoute;

  //optional route Customization
  @CupertinoRoute(fullscreenDialog: true)
  LoginScreen loginScreenRoute;
}

Now simply Run the generator

Use the [watch] flag to watch the files system for edits and rebuild as necessary.

flutter packages pub run build_runner watch

if you want the generator to run one time and exits use

flutter packages pub run build_runner build

Finalize the Setup

after you run the generator your router class will be generated containing all of your route names and the onGenerateRoute function implementation.

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
    // hook up the onGenerateRoute function in the generated Router class
    // with your Material app
      onGenerateRoute: MyRouter.onGenerateRoute,
      // optional
      initialRoute: MyRouter.homeScreenRoute,
    );
  }
}

Inside of the Generated class

class Router{
   // your route names will be generated as static const Strings
  static const loginScreenRoute = '/loginScreenRoute';

      static Route<dynamic> onGenerateRoute(RouteSettings settings) {
        switch (settings.name) {
        // The generated code for LoginScreen is
          case Router.loginScreenRoute:
            return CupertinoPageRoute(
              builder: (_) => LoginScreen(),
              settings: settings,
              fullscreenDialog: true
            );

          default:
          // autoRoute handles unknown routes for you
            return unknownRoutePage(settings.name);
        }
 } }

Customization

---

@AutoRouter

Property	Default value	Definition
generateNavigator [bool]	true	if true a navigator key will be generated with helper accessors
generateRouteList [bool]	false	if true a list of all routes will be generated

@MaterialRoute | @CupertinoRoute | @CustomRoute

Property	Default value	Definition
initial [bool]	false	mark the route as initial '\'
name [String]	null	this will be assigned to the route variable name if provided (String homeScreen = [name]);
fullscreenDialog [bool]	false	extension for the fullscreenDialog property in PageRoute
maintainState [bool]	true	extension for the maintainState property in PageRoute

@CupertinoRoute Specific => CupertinoPageRoute

Property	Default value	Definition
title [String]	null	extension for the title property in CupertinoPageRoute

@CustomeRoute Specific => PageRouteBuilder

Property	Default value	Definition
transitionsBuilder [Function]	null	extension for the transitionsBuilder property in PageRouteBuilder
opaque [bool]	true	extension for the opaque property in PageRouteBuilder
barrierDismissible [bool]	false	extension for the barrierDismissible property in PageRouteBuilder
durationInMilliseconds [double]	null	extension for the transitionDuration(millieSeconds) property in PageRouteBuilder

Passing Arguments to Routes

---

That's the fun part!

You don't actually need to do anything extra. AutoRoute automatically detects your route parameters and handles them for you, and because Types are important it will make sure you pass the right argument Type

class ProductDetails extends StatelessWidget {
  final int productId;
// your route parameters are handled based on
// your widget route constructor
  const ProductDetails(this.productId);
  @override
  Widget build(BuildContext context)...
}

Generated code for the above example

 final args = settings.arguments;
  case Router.productDetailsRoute:
   // ProductDetails screen is expecting a productId of type <int>
   // so we check the passed arguments against it
    if (hasInvalidArgs<int>(args))
    // if the passed in args are mistyped, an error route page will be displayed instead
    return misTypedArgsRoute<int>(args);
    // otherwise we navigate to the desired screen
    final typedArgs = args as int;
    return MaterialPageRoute(
      builder: (_) => ProductDetails(typedArgs),
      settings: settings,
    );

Passing multiple arguments (Don't worry, We're not using a dynamic Map!)

Since you can only pass one argument to the Navigator, if you define more then one parameter in your screen constructor autoRoute will automatically generate a class that holds your screen arguments and keep them typed.

class WelcomeScreen extends StatelessWidget {
  final String title;
  final String message;
  const WelcomeScreen({this.title = "Default Title",@required this.message});

  @override
  Widget build(BuildContext context)...
}

Generated code for the above example

• Default values are respected.
• Required fields are also respected and handled properly.

//WelcomeScreen arguments holder class is generated
class WelcomeScreenArguments {
  final String title;
  final String message;
  // you're not going to lose your default values;
  WelcomeScreenArguments({this.title = "Default Title",@required this.message});
}

 case Router.welcomeScreenRoute:
      // if your class holder contains at least one required field the whole argument class is considered required and can not be null
        if (hasInvalidArgs<WelcomeScreenArguments>(args,isRequired: true))
          return misTypedArgsRoute<WelcomeScreenArguments>(args);
        final typedArgs =
            args as WelcomeScreenArguments ?? WelcomeScreenArguments();
        return MaterialPageRoute(
          builder: (_) =>
              WelcomeScreen(title: typedArgs.title, message: typedArgs.message),
          settings: settings,
        );

Pass your typed args using the generated arguments holder class

Navigator.of(ctx).pushNamed(Router.welcomeScreenRoute,
    arguments: WelcomeScreenArguments(
        title: "Hello World!"
        message: "Let's AutoRoute!"
        )
    );

Navigating Using a Global Navigator Key aka Navigating Without Context

Simply assign MyRouter.navigatorKey to the MaterialApp property "navigatorKey" as follows

  MaterialApp(
      onGenerateRoute: MyRouter.onGenerateRoute,
      // hook up the navigatorKey
      navigatorKey: MyRouter.navigatorKey,
    );
}

Now use the navigator inside of MyRouter any where in your app.

---

MyRouter.navigator.pushNamed(MyRouter.secondScreen);

Nested Navigators

Create your nested router class and define your routes as before.

@autoRouter
class $MyNestedRouter {
  @initial
  NestedHomePage nestedHomePage;
  NestedSecondPage nestedSecondPage;
}

Hook up your nested navigator with the Generated Router class

 Navigator(
          key: MyNestedRouter.navigatorKey,
          onGenerateRoute: MyNestedRouter.onGenerateRoute),

And That's that! Now use your nested router's navigator to navigate within your nested navigator as follows

MyNestedRouter.navigator.pushNamed("your Nested route")

Handling Wrapped Routes

---

To wrap your route with a parent widget like a Provider or such, simply implement AutoRouteWrapper, and let wrappedRoute accessor return (this) as the child of your wrapper widget.

class ProductsScreen extends StatelessWidget implements AutoRouteWrapper {
  @override
  Widget get wrappedRoute => Provider(create: (ctx) => ProductsBloc(), child: this);
  ...
  }

Custom Route Transitions

---

To use custom Transitions use the @CustomRoute() annotation and pass in your preferences.
The TransitionsBuilder function needs to be passed as a static/const reference that has the same signature as the TransitionsBuilder Function of the PageRouteBuilder class.
The included TransitionsBuilders Class contains a preset of common Transitions builders

@CustomRoute(transitionsBuilder: TransitionBuilders.slideBottom,durationInMilliseconds: 400)
LoginScreen loginScreenRoute;

You can of course use your own transitionsBuilder function as long as it has the same function signature.
The function has to take in exactly a BuildContext, Animation[Double], Animation[Double] and a child Widget and it needs to return a Widget, typically you would wrap your child with one of flutter's transition Widgets as follows.

Widget zoomInTransition(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
 // you get an animation object and a widget
 // make your own transition
    return ScaleTransition(scale: animation, child: child);
  }

Now pass the reference of your function to @CustomRoute() annotation.

@CustomRoute(transitionsBuilder: zoomInTransition)
ZoomInScreen zoomInScreenRoute {}

Resources

---

• Lean how to setup and use auto_route with this well made tutorial by Reso Coder

Acknowledgements

---

Thanks to Peter Leibiger for his valuable advice.

Problems with the generation?

---

Make sure you always Save your files before running the generator, if that doesn't work you can always try to clean and rebuild.

flutter packages pub run build_runner clean