As you know, Routing
is a pattern matching system that monitor the incoming request and
figure out what to do with that request. A URL pattern is matched
against the routes patterns defined in the Route dictionary in an Order
and the first match wins. This means the first route which successfully
matches a controller, action, and action parameters defined in the URL
will call into the specified controller and action.
Asp.Net MVC application and Asp.Net Web API must have at least one
route defined in order to function. Hence, Visual Studio templates
defined for MVC and Web API must have a default route. Now let's
understand the difference between Asp.Net MVC and Asp.Net Web API.Default Route Pattern
The default route pattern for a Web API Project is defined as follows-The literal
- config.Routes.MapHttpRoute(
- name: "DefaultApi", //route name
- routeTemplate: "api/{controller}/{id}", //route pattern
- defaults: new { id = RouteParameter.Optional } //parameter default values
- );
api at the beginning of the Web API route
pattern, makes it distinct from the standard MVC route. This is not
mandatory but it is a good convention to differ Web API route from MVC
route. In Web API route pattern {action} parameter is optional but you can include an {action} parameter. Also, the action methods defined on the controller must be have an HTTP action verb as a prefix to the method name in order to work. So, you can also define the route for Web API as follows-
The default route pattern for an Asp.Net MVC Project is defined as follows-
- config.Routes.MapHttpRoute(
- name: "DefaultApi",//route name
- routeTemplate: "api/{controller}/{action}/{id}",//route pattern
- defaults: new { id = RouteParameter.Optional }//parameter default values
- );
As you have seen there is no literal before at the beginning of the Asp.Net MVC route pattern but you can add if you wish.
- routes.MapRoute(
- name: "Default", //route name
- url: "{controller}/{action}/{id}", //route pattern
- defaults: new
- {
- controller = "Home",
- action = "Index",
- id = UrlParameter.Optional
- } //parameter default values
- );
Route Processing
In Web API route processing the URLs map to a controller, and then to the action which matches the HTTP verb of the request and the most parameters of the request is selected. The Action methods defined in the API controller must either have the HTTP action verbs (GET, POST, PUT, DELETE) or have one of the HTTP action verbs as a prefix for the Actions methods name as given below-In Asp.Net MVC route processing the URLs map to a controller, and then to the action which matches the HTTP verb of the request and the most parameters of the request is selected. The Action methods defined in the MVC controller do not have HTTP action verbs as a prefix for the Actions methods but they have name like as normal method as shown below-
- public class ValuesController : ApiController
- {
- // GET api/
- public IEnumerable Get()
- {
- return new string[] { "value1", "value2" };
- }
- // GET api//5
- public string Get(int id)
- {
- return "value";
- }
- // POST api/
- public void Post([FromBody]string value)
- {
- }
- // PUT api//5
- public void Put(int id, [FromBody]string value)
- {
- }
- // DELETE api//5
- public void Delete(int id)
- {
- }
- }
- // OR You can also defined above API Controller as Verb Prefix
- public class ValuesController : ApiController
- {
- // GET api/values
- public IEnumerable GetValues()
- {
- return new string[] { "value1", "value2" };
- }
- // GET api/values/5
- public string GetValues(int id)
- {
- return "value";
- }
- // POST api/values
- public void PostValues([FromBody]string value)
- {
- }
- // PUT api/values/5
- public void PutValues(int id, [FromBody]string value)
- {
- }
- // DELETE api/values/5
- public void DeleteValues(int id)
- {
- }
- }
In MVC, by default HTTP verb is GET for using others HTTP verbs you need defined as an attribute but in Web API you need to define as an method's name prefix.
- public class HomeController : Controller
- {
- // GET: /Home/Index
- public ActionResult Index() //method - Index
- {
- // To Do:
- return View();
- }
- // Post: /Home/Index
- [HttpPost]
- public ActionResult Index(LoginModel model, string id)
- {
- // To Do:
- return View();
- }
- }
Complex Parameter Processing
Unlike MVC, URLs in Web API cannot contain complex types. Complex types must be placed in the HTTP message body and there should be only one complex type in the body of an HTTP message.Base Library
Web API controllers inherit fromSystem.Web.Http.Controller, but MVC controllers inherit from System.Web.Mvc.Controller. Both the library are different but acts in similar fashion.
