auto_route_generator

A generator for auto_route library.

auto_route:

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

Installation

dependencies:  
# add auto_route to your dependencies  
  auto_route:  
  
dev_dependencies:  
# add the generator to your dev_dependencies  
  auto_route_generator:  
# 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 desired name minus the $.
$Router => Router

Note: using $ prefix is mandatory.
@autoRouter  
class $Router {  
  
}

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

You don't have to annotate very single route with @MaterialRoute() or @CupertinoRoute()
@autoRouter  
class $Router {  
 // use @initial or @CupertinoRoute(initial: true) to annotate your initial route.  
  @initial  
  HomeScreen homeScreenRoute; // your desired route name  
  
  SecondScreen secondScreenRoute;  
  
  //only use the @MaterialRoute() or @CupertinoRoute() annotations to customize your route  
  @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);  
        }  
 } }

Passing Arugments 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!"  
        )  
    );

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 wrappeRoute 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, Animation and a child Widget and it needs to return a Widget, typically you would wrap your child with one of flutter's transtion 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 {}

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

Libraries

auto_route_generator
builder
route_config_visitor
router_class_generator
utils