Attribute Routing With ASP.net MVC 5

Introduction

• This Article shows how to use the Latest ASP.net MVC 5 Attribute Routing with your Application.
• This Article has 2 parts.First part of this Article will show the basic usage of Attribute Routing.
• Now you can read the 2nd part of this Article here 'Attribute Routing With ASP.net MVC 5 - Route Constraints' 

What is Routing ?

• Routing is how ASP.net MVC matches a URI to an Action

What is Attribute Routing ?

• ASP.net MVC 5 supports a new type of Routing, called Attribute Routing
• As the name implies, attribute routing uses attributes to define routes
• Attribute routing gives you more control over the URIs in your web application

How To Enable Attribute Routing ?

• For that, You have to select the RouteConfig.cs inside the App_Start Folder.
• After that call MapMvcAttributeRoutes is as below.

RouteConfig.cs

public class RouteConfig

    {

        public static void RegisterRoutes(RouteCollection routes)

        {

            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapMvcAttributeRoutes();//Attribute Routing

            //Convention-based Routing

            routes.MapRoute(

                name: "Default",

                url: "{controller}/{action}/{id}",

                defaults: new { controller = "Home", action = "Index",

                                id = UrlParameter.Optional }

            );

        }

    }

Key points of the above code

• To enable Attribute Routing,You have to call MapMvcAttributeRoutes on RouteConfig File.
• If you want, You can keep the Convention-based Routing also with the same file is as above.
• But routes.MapMvcAttributeRoutes(); Should configure before the Convention-based Routing.

How to use Optional URI Parameters ?

• To that you can add a question mark to the Route parameter
• Well, It's like this : [Route("Pet/{petKey?}")]

    PetController.cs

  public class PetController : Controller

    {

        // eg: /Pet

        // eg: /Pet/123

        [Route("Pet/{petKey?}")]

        public ActionResult GetPet(string petKey)

        {

            return View();

        }

       }

Key point of the above code

• In the above example, both /Pet and /Pet/123 will Route to the “GetPet” Action

Above Route on Browser is as below

                  

How to use Default Values URI Parameters ?

• To that you can specify a default value  to the route parameter
• It's like this : [Route("Pet/Breed/{petKey=123}")]

       PetController.cs
        

    public class PetController : Controller

     {

        // eg: /Pet/Breed

        // eg: /Pet/Breed/528

        [Route("Pet/Breed/{petKey=123}")]

        public ActionResult GetSpecificPet(string petKey)

        {

            return View();

        }

     }

Key point of the above code

• In the above example, both /Pet/Breed and /Pet/Breed/528 will route to the “GetSpecificPet” Action

Above Route on Browser is as below

How to use Route Prefixes ?

• Normally, the routes in a controller all start with the same prefix
• Well,It's like this : /Booking

BookingController.cs

public class BookingController : Controller
    {

        // eg: /Booking

        [Route("Booking")]

        public ActionResult Index() { return View(); }

        // eg: /Booking/5

        [Route("Booking/{bookId}")]

        public ActionResult Show(int bookId) { return View(); }

        // eg: /Booking/5/Edit

        [Route("Booking/{bookId}/Edit")]

        public ActionResult Edit(int bookId) { return View(); }

    }

Above Routes on Browser are as below

How to Set Common Route Prefix ?

• If you want, you can specify a common prefix for an entire controller
• To that you can use [RoutePrefix] attribute
• It's like this : [RoutePrefix("Booking")]

    

       BookingController.cs

    [RoutePrefix("Booking")]

    public class BookingController : Controller

    {

        // eg: /Booking

        [Route]

        public ActionResult Index() { return View(); }

        // eg: /Booking/5

        [Route("{bookId}")]

        public ActionResult Show(int bookId) { return View(); }

        // eg: /Booking/5/Edit

        [Route("{bookId}/Edit")]

        public ActionResult Edit(int bookId) { return View(); }

    }

Above Routes on Browser are as below

How to Override the Common Route Prefix ?

• You can use a tilde (~) on the method attribute to override the route prefix
• Well,It's like this : [Route("~/PetBooking")]

       

        BookingController.cs

    [RoutePrefix("Booking")]

    public class BookingController : Controller

    {

        // eg: /PetBooking

        [Route("~/PetBooking")]

        public ActionResult PetBooking() { return View(); }

    }

Above Route on Browser is as below

How to use Default Route ?

• You can apply the [Route] attribute on the Controller level and put the Action as a parameter
• That Route will then be applied on all Actions in the Controller
• Well,It's like this : [Route("{action=index}")]

      

       BookingController.cs

    [RoutePrefix("Booking")]

    [Route("{action=index}")]

    public class BookingController : Controller

    {

        // eg: /Booking

        public ActionResult Index() { return View(); }

        // eg: /Booking/Show

        public ActionResult Show() { return View(); }

        // eg: /Booking/New

        public ActionResult New() { return View(); }

    }

Above Routes on Browser are as below

How to override Default Route ?

• For that you have to use specific [Route] on a specific Action.
• It'll override the default settings on the Controller.

       BookingController.cs

    [RoutePrefix("Booking")]

    [Route("{action=index}")]

    public class BookingController : Controller

    {

        // eg: /Booking

        public ActionResult Index() { return View(); }

        // eg: /Booking/Edit/3

        [Route("Edit/{bookId:int}")]

        public ActionResult Edit(int bookId) { return View(); }

    }

Above overridden Route on Browser is as below

How to give Route Names ?

• You can specify a Name for a Route
• By using that Name, you can easily allow URI generation for it
• Well,It's like this : [Route("Booking", Name = "Payments")]

  BookingController.cs

 public class BookingController : Controller

    {

        // eg: /Booking

        [Route("Booking", Name = "Payments")]

        public ActionResult Payments() { return View(); }

    }

• After that you can generate a Link is using Url.RouteUrl
• It's like this : 

    <a href="@Url.RouteUrl("Payments")">Payments Screen</a>

Note : On the above code, "Payments" is a Route Name

Advantages of Attribute Routing Over the Convention-based Routing

• Attribute Routing gives you more control over the URIs in your web application
• Easy to Troubleshoot issues
• No fear of modifying anything will break another route down the line 

Used Dev. Environment in Article's Source Code

• Visual Studio 2013 Express
• .Net Framework 4.5.1
• ASP.net MVC 5
• C#

Conclusion

• You saw that how easily can configure the URI Routines with Attribute Routing
• In my next article I will show how to apply Attribute Routing with Route Constraints, Custom Route Constraints and Areas
• So enjoy this Awesome New Feature of ASP.net MVC 5

I hope this helps to You.Comments and feedback greatly appreciated.

If you feel it was a good article,Give me a +1.Thank You.

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