Implicit Verbs from Method name

Implicit Verbs from Method name - c#

If I create a webApi controller, and populate it with methods prefixed with http verbs, the Api is able to correctly imply what verb should be used on that controller.
public class TestController : ApiController
{
public string GetData()
{
return "Called Get Method";
}
public string PostData()
{
return "Called Post Method";
}
public string PutData()
{
return "Called Put Method";
}
}
If I replace the Post with Update, the Post method continues to work implicitly.
public string UpdateData()
{
return "Called Updated Method";
}
Is there a list of the possible prefixes on a method and what verb they map to? Additionally, is it possible to define custom prefixes? For instance, if I wanted to always map a method starting with "Search" to a Post, can I define this?

If you put your Routing like the following :
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
Consider the routeTemplate.You'll now be able to call the actions on the controller by name,and no prefix issue should exist. This approach is very helpful if you have multiple actions on your controller with similar HTTP Verbs(multiple GET or POST say).

Implicit Verbs are a function of the built in routing, and cannot appear to be manually extended.
This Asp.Net details the specific rules around the implicit routing.
HTTP Methods. The framework only chooses actions that match the HTTP method of the request, determined as follows:
You can specify the HTTP method with an attribute: AcceptVerbs, HttpDelete, HttpGet, HttpHead, HttpOptions, HttpPatch, HttpPost, or HttpPut.
Otherwise, if the name of the controller method starts with "Get", "Post", "Put", "Delete", "Head", "Options", or "Patch", then by convention the action supports that HTTP method.
If none of the above, the method supports POST.
The reason why the UpdateData method appears to work, is because any method not implicitly determined is automatically a Post

Related

ASP.NET MVC new Routes not working

I am using ASP.NET MVC and I am trying to create a new route for a parameter like so:
config.Routes.MapHttpRoute(
name: "MarkOnline",
routeTemplate: "api/{controller}/{id}",
defaults: new { offline = RouteParameter.Optional }
);
and here is my method call I am trying to use inside my API Controller
public void MarkOnline(string offline)
{
}
however what gets returned is my Entity Framework GetData method in the API Controller, which is this:
public IQueryable<VistaLCPreview> GetData()
{
return db.Data;
}
What am I doing wrong?

In this context, GetData is being called due to the fact that it has a prefix of Get. There's a convention that maps HTTP GET to functions prefixed with Get, HTTP POST to PostXXX, etc. GetData is being resolved by the default HTTP route, which specifies an optional id parameter and is not present in your expected GetData URL example (which is what you want there).
The MapHttpRoute from your example is not going to match, due to the id parameter in the routeTemplate, which has not been defaulted to RouteParameter.Optional. This route is actually unnecessary - You do not need to include query-string parameters in this route definition. Query-string parameters are simply mapped into the arguments passed into the actions (offline in your case).
Because MarkOnline is not prefixed with one of the HTTP Verbs as I mentioned above, it is not being matched by the default HTTP route. To fix your problem you simply need to do two things:
Remove the MapHttpRoute that you added. This is not needed as the default HTTP route I've already mentioned will cover your use-case.
Add the HttpGet attribute to your MarkOnline method. This will cause the routing to pick up MarkOnline when an offline query-string parameter is found, but call GetData when it is not.

Your route is not configured correctly, you are not specifying the default action on your controller.
It should be something like this:
routes.MapRoute(
name: "MarkOnlineRoute",
url: "api/{controller}",
defaults: new { action = "MarkOnline" }
);
But also notice that the order which you configure your routes is important, it should be located before the default route configuration:
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
And as a reference, this is my test controller:
public class AvailabilityController : Controller
{
// GET: MarkOnline
public void MarkOnline(string offline)
{
//return Json(new { isOnline = true, name=offline }, JsonRequestBehavior.AllowGet);
}
}
And it is called with: http://localhost/api/availability?offline=xxx#xxx.com

No action was found on the controller ApiController

For my API, I want to be able to handle scenarios where the call is made using an incorrect URL (i.e. URL that does not match any controller or action.)
For this I have implemented routing so that it matches any route:
config.Routes.MapHttpRoute(
name: "CatchAll",
routeTemplate: "{*any}",
defaults: new { controller = "Error", action = "Handler" }
);
And I have implemented the controller - action as follows:
[Route("api/v1/Handler")]
[ActionName("Handler")]
public HttpResponseMessage Get() {...}
When I give an incorrect URL, I get the message:
No action was found on the controller 'Error' that matches the name 'Handler'
Not sure where the mistake is.

Simple approach:
You need to match the action name. So either rename Get to Handler in the ErrorController and remove attributes as they will conflict with conventions you mapped .
public HttpResponseMessage Handler(string any) {...}
or change action from Handler to Get in the Catch all MapHttpRoute
config.Routes.MapHttpRoute(
name: "CatchAll",
routeTemplate: "{*any}",
defaults: new { controller = "Error", action = "Get" }
);
Not so simple approach:
Here is how I handled the same thing in my web api using attribute routing and inheritance.
First I created a base api controller that will handler unknown actions.
public abstract class WebApiControllerBase : ApiController {
[Route("{*actionName}")]
[AcceptVerbs("GET", "POST", "PUT", "DELETE")]
[AllowAnonymous]
[ApiExplorerSettings(IgnoreApi = true)]
public virtual HttpResponseMessage HandleUnknownAction(string actionName) {
var status = HttpStatusCode.NotFound;
var message = "[Message placeholder]";
var content = new { message = message, status = status};
return Request.CreateResponse(status, content);
}
}
My Api controllers all inherit from this base controller.
[RoutePrefix("api/customers")]
public class CustomersApiController : WebApiControllerBase {...}
Given that your question included RouteAttribute you should already be using MapHttpAttributeRoutes in your web api config.
But there's more. To get the framework to recognize the inherited attributes you need to override the DefaultDirectRouteProvider as outlined here
and used in an answer here
WebAPI controller inheritance and attribute routing
public class WebApiCustomDirectRouteProvider : DefaultDirectRouteProvider {
protected override System.Collections.Generic.IReadOnlyList<IDirectRouteFactory>
GetActionRouteFactories(System.Web.Http.Controllers.HttpActionDescriptor actionDescriptor) {
// inherit route attributes decorated on base class controller's actions
return actionDescriptor.GetCustomAttributes<IDirectRouteFactory>(inherit: true);
}
}
and apply that to the web api configuration.
// Attribute routing. (with inheritance)
config.MapHttpAttributeRoutes(new WebApiCustomDirectRouteProvider());
Hope this helps

Defining two get function in WebAPI

I am getting to following exception when i am trying to call a GET function in MVC WebAPI
{"$id":"1","Message":"An error has occurred.",
"ExceptionMessage":"Multiple actions were found that match the request:
\r\nSystem.Xml.XmlNode Get(Int32, System.String)
I think the problem is cause due to two get function
I have defined two functions:
One:
[HttpGet]
public XmlNode Get(int id, string Tokken)
{
//Do something
}
Second One
[HttpGet]
public List<UsersAnswers> GetUsersInteractions(int? activityID, string Tokken)
{
// Do Something
}
The route configuration
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
Now i am getting the exception when i try to call to the second function:
{SiteURL}/api/Activities/GetUsersInteractions?activityID=32&Tokken=r54e54353
As you can see the route engine sent the request to the first function instead of the second.
How can i define two get operation and to call each one separately?

With the default routing template, Web API uses the HTTP method to select the action. However, you can also create a route where the action name is included in the URI:
routes.MapHttpRoute(
name: "ActionApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
In this route template, the {action} parameter names the action method on the controller. With this style of routing, use attributes to specify the allowed HTTP methods. For example, suppose your controller has the following method:
public class ProductsController : ApiController
{
[HttpGet]
public string Details(int id);
}
In this case, a GET request for “api/products/details/1” would map to the Details method. This style of routing is similar to ASP.NET MVC, and may be appropriate for an RPC-style API.
You can override the action name by using the ActionName attribute. In the following example, there are two actions that map to "api/products/thumbnail/id. One supports GET and the other supports POST:
public class ProductsController : ApiController
{
[HttpGet]
[ActionName("Thumbnail")]
public HttpResponseMessage GetThumbnailImage(int id);
[HttpPost]
[ActionName("Thumbnail")]
public void AddThumbnailImage(int id);
}

You are not calling the second function - the second function is named InsertUserRecord and is a POST method. The function you're calling via GET is GetUserInteractions. As there's no such function for GET, the engine may map this to the only GET function there is, but actually it should throw a "no such function" error.

Api controller declaring more than one Get statement

Using the new Api Controller in MVC4, and I've found a problem. If I have the following methods:
public IEnumberable<string> GetAll()
public IEnumberable<string> GetSpecific(int i)
This will work. However, if I want to retrieve some different data of a different type, it defaults to the GetAll method, even though the $.getJSON is set to the GetAllIntegers method:
public IEnumberable<int> GetAllIntergers()
(bad naming conventions)
Is it possible for me to be able to do this?
Can I only have a single GetAll method in the Web API controller?
I think it's easier to visualise what I'm trying to achieve. Here is a snippet of code to show what I'd like to be able to do, in a single ApiController:
public IEnumerable<string> GetClients()
{ // Get data
}
public IEnumerable<string> GetClient(int id)
{ // Get data
}
public IEnumerable<string> GetStaffMember(int id)
{ // Get data
}
public IEnumerable<string> GetStaffMembers()
{ // Get data
}

This is all in the routing. The default Web API route looks like this:
config.Routes.MapHttpRoute(
name: "API Default",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
With the default routing template, Web API uses the HTTP method to select the action. In result it will map a GET request with no parameters to first GetAll it can find. To work around this you need to define a route where the action name is included:
config.Routes.MapHttpRoute(
name: "ActionApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
After that you can star making requests with following URL's:
api/yourapicontroller/GetClients
api/yourapicontroller/GetStaffMembers
This way you can have multiple GetAll in Controller.
One more important thing here is that with this style of routing, you must use attributes to specify the allowed HTTP methods (like [HttpGet]).
There is also an option of mixing the default Web API verb based routing with traditional approach, it is very well described here:
Web API: Mixing Traditional & Verb-Based Routing

In case someone else faces this problem. Here's how I solved this. Use the [Route] attribute on your controller to route to a specific url.
[Route("api/getClient")]
public ClientViewModel GetClient(int id)
[Route("api/getAllClients")]
public IEnumerable<ClientViewModel> GetClients()

Custom method names in ASP.NET Web API

I'm converting from the WCF Web API to the new ASP.NET MVC 4 Web API. I have a UsersController, and I want to have a method named Authenticate. I see examples of how to do GetAll, GetOne, Post, and Delete, however what if I want to add extra methods into these services? For instance, my UsersService should have a method called Authenticate where they pass in a username and password, however it doesn't work.
public class UsersController : BaseApiController
{
public string GetAll()
{
return "getall!";
}
public string Get(int id)
{
return "get 1! " + id;
}
public User GetAuthenticate(string userName, string password, string applicationName)
{
LogWriter.Write(String.Format("Received authenticate request for username {0} and password {1} and application {2}",
userName, password, applicationName));
//check if valid leapfrog login.
var decodedUsername = userName.Replace("%40", "#");
var encodedPassword = password.Length > 0 ? Utility.HashString(password) : String.Empty;
var leapFrogUsers = LeapFrogUserData.FindAll(decodedUsername, encodedPassword);
if (leapFrogUsers.Count > 0)
{
return new User
{
Id = (uint)leapFrogUsers[0].Id,
Guid = leapFrogUsers[0].Guid
};
}
else
throw new HttpResponseException("Invalid login credentials");
}
}
I can browse to myapi/api/users/ and it will call GetAll and I can browse to myapi/api/users/1 and it will call Get, however if I call myapi/api/users/authenticate?username={0}&password={1} then it will call Get (NOT Authenticate) and error:
The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.String Get(Int32)' in 'Navtrak.Services.WCF.NavtrakAPI.Controllers.UsersController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
How can I call custom method names such as Authenticate?

By default the route configuration follows RESTFul conventions meaning that it will accept only the Get, Post, Put and Delete action names (look at the route in global.asax => by default it doesn't allow you to specify any action name => it uses the HTTP verb to dispatch). So when you send a GET request to /api/users/authenticate you are basically calling the Get(int id) action and passing id=authenticate which obviously crashes because your Get action expects an integer.
If you want to have different action names than the standard ones you could modify your route definition in global.asax:
Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { action = "get", id = RouteParameter.Optional }
);
Now you can navigate to /api/users/getauthenticate to authenticate the user.

This is the best method I have come up with so far to incorporate extra GET methods while supporting the normal REST methods as well. Add the following routes to your WebApiConfig:
routes.MapHttpRoute("DefaultApiWithId", "Api/{controller}/{id}", new { id = RouteParameter.Optional }, new { id = #"\d+" });
routes.MapHttpRoute("DefaultApiWithAction", "Api/{controller}/{action}");
routes.MapHttpRoute("DefaultApiGet", "Api/{controller}", new { action = "Get" }, new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) });
routes.MapHttpRoute("DefaultApiPost", "Api/{controller}", new {action = "Post"}, new {httpMethod = new HttpMethodConstraint(HttpMethod.Post)});
I verified this solution with the test class below. I was able to successfully hit each method in my controller below:
public class TestController : ApiController
{
public string Get()
{
return string.Empty;
}
public string Get(int id)
{
return string.Empty;
}
public string GetAll()
{
return string.Empty;
}
public void Post([FromBody]string value)
{
}
public void Put(int id, [FromBody]string value)
{
}
public void Delete(int id)
{
}
}
I verified that it supports the following requests:
GET /Test
GET /Test/1
GET /Test/GetAll
POST /Test
PUT /Test/1
DELETE /Test/1
Note That if your extra GET actions do not begin with 'Get' you may want to add an HttpGet attribute to the method.

I am days into the MVC4 world.
For what its worth, I have a SitesAPIController, and I needed a custom method, that could be called like:
http://localhost:9000/api/SitesAPI/Disposition/0
With different values for the last parameter to get record with different dispositions.
What Finally worked for me was:
The method in the SitesAPIController:
// GET api/SitesAPI/Disposition/1
[ActionName("Disposition")]
[HttpGet]
public Site Disposition(int disposition)
{
Site site = db.Sites.Where(s => s.Disposition == disposition).First();
return site;
}
And this in the WebApiConfig.cs
// this was already there
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
// this i added
config.Routes.MapHttpRoute(
name: "Action",
routeTemplate: "api/{controller}/{action}/{disposition}"
);
For as long as I was naming the {disposition} as {id} i was encountering:
{
"Message": "No HTTP resource was found that matches the request URI 'http://localhost:9000/api/SitesAPI/Disposition/0'.",
"MessageDetail": "No action was found on the controller 'SitesAPI' that matches the request."
}
When I renamed it to {disposition} it started working. So apparently the parameter name is matched with the value in the placeholder.
Feel free to edit this answer to make it more accurate/explanatory.

Web Api by default expects URL in the form of api/{controller}/{id}, to override this default routing. you can set routing with any of below two ways.
First option:
Add below route registration in WebApiConfig.cs
config.Routes.MapHttpRoute(
name: "CustomApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
Decorate your action method with HttpGet and parameters as below
[HttpGet]
public HttpResponseMessage ReadMyData(string param1,
string param2, string param3)
{
// your code here
}
for calling above method url will be like below
http://localhost:[yourport]/api/MyData/ReadMyData?param1=value1&param2=value2&param3=value3
Second option
Add route prefix to Controller class and Decorate your action method with HttpGet as below.
In this case no need change any WebApiConfig.cs. It can have default routing.
[RoutePrefix("api/{controller}/{action}")]
public class MyDataController : ApiController
{
[HttpGet]
public HttpResponseMessage ReadMyData(string param1,
string param2, string param3)
{
// your code here
}
}
for calling above method url will be like below
http://localhost:[yourport]/api/MyData/ReadMyData?param1=value1&param2=value2&param3=value3

In case you're using ASP.NET 5 with ASP.NET MVC 6, most of these answers simply won't work because you'll normally let MVC create the appropriate route collection for you (using the default RESTful conventions), meaning that you won't find any Routes.MapRoute() call to edit at will.
The ConfigureServices() method invoked by the Startup.cs file will register MVC with the Dependency Injection framework built into ASP.NET 5: that way, when you call ApplicationBuilder.UseMvc() later in that class, the MVC framework will automatically add these default routes to your app. We can take a look of what happens behind the hood by looking at the UseMvc() method implementation within the framework source code:
public static IApplicationBuilder UseMvc(
[NotNull] this IApplicationBuilder app,
[NotNull] Action<IRouteBuilder> configureRoutes)
{
// Verify if AddMvc was done before calling UseMvc
// We use the MvcMarkerService to make sure if all the services were added.
MvcServicesHelper.ThrowIfMvcNotRegistered(app.ApplicationServices);
var routes = new RouteBuilder
{
DefaultHandler = new MvcRouteHandler(),
ServiceProvider = app.ApplicationServices
};
configureRoutes(routes);
// Adding the attribute route comes after running the user-code because
// we want to respect any changes to the DefaultHandler.
routes.Routes.Insert(0, AttributeRouting.CreateAttributeMegaRoute(
routes.DefaultHandler,
app.ApplicationServices));
return app.UseRouter(routes.Build());
}
The good thing about this is that the framework now handles all the hard work, iterating through all the Controller's Actions and setting up their default routes, thus saving you some redundant work.
The bad thing is, there's little or no documentation about how you could add your own routes. Luckily enough, you can easily do that by using either a Convention-Based and/or an Attribute-Based approach (aka Attribute Routing).
Convention-Based
In your Startup.cs class, replace this:
app.UseMvc();
with this:
app.UseMvc(routes =>
{
// Route Sample A
routes.MapRoute(
name: "RouteSampleA",
template: "MyOwnGet",
defaults: new { controller = "Items", action = "Get" }
);
// Route Sample B
routes.MapRoute(
name: "RouteSampleB",
template: "MyOwnPost",
defaults: new { controller = "Items", action = "Post" }
);
});
Attribute-Based
A great thing about MVC6 is that you can also define routes on a per-controller basis by decorating either the Controller class and/or the Action methods with the appropriate RouteAttribute and/or HttpGet / HttpPost template parameters, such as the following:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNet.Mvc;
namespace MyNamespace.Controllers
{
[Route("api/[controller]")]
public class ItemsController : Controller
{
// GET: api/items
[HttpGet()]
public IEnumerable<string> Get()
{
return GetLatestItems();
}
// GET: api/items/5
[HttpGet("{num}")]
public IEnumerable<string> Get(int num)
{
return GetLatestItems(5);
}
// GET: api/items/GetLatestItems
[HttpGet("GetLatestItems")]
public IEnumerable<string> GetLatestItems()
{
return GetLatestItems(5);
}
// GET api/items/GetLatestItems/5
[HttpGet("GetLatestItems/{num}")]
public IEnumerable<string> GetLatestItems(int num)
{
return new string[] { "test", "test2" };
}
// POST: /api/items/PostSomething
[HttpPost("PostSomething")]
public IActionResult Post([FromBody]string someData)
{
return Content("OK, got it!");
}
}
}
This controller will handle the following requests:
[GET] api/items
[GET] api/items/5
[GET] api/items/GetLatestItems
[GET] api/items/GetLatestItems/5
[POST] api/items/PostSomething
Also notice that if you use the two approaches togheter, Attribute-based routes (when defined) would override Convention-based ones, and both of them would override the default routes defined by UseMvc().
For more info, you can also read the following post on my blog.

See this article for a longer discussion of named actions. It also shows that you can use the [HttpGet] attribute instead of prefixing the action name with "get".
http://www.asp.net/web-api/overview/web-api-routing-and-actions/routing-in-aspnet-web-api

Web APi 2 and later versions support 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 API. For example, you can easily create URIs that describe hierarchies of resources.
For example:
[Route("customers/{customerId}/orders")]
public IEnumerable<Order> GetOrdersByCustomer(int customerId) { ... }
Will perfect and you don't need any extra code for example in WebApiConfig.cs.
Just you have to be sure web api routing is enabled or not in WebApiConfig.cs , if not you can activate like below:
// Web API routes
config.MapHttpAttributeRoutes();
You don't have to do something more or change something in WebApiConfig.cs. For more details you can have a look this article.

Just modify your WebAPIConfig.cs as bellow
Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { action = "get", id = RouteParameter.Optional });
Then implement your API as bellow
// GET: api/Controller_Name/Show/1
[ActionName("Show")]
[HttpGet]
public EventPlanner Id(int id){}

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

Implicit Verbs from Method name - c#

Related

ASP.NET MVC new Routes not working

No action was found on the controller ApiController

Defining two get function in WebAPI

Api controller declaring more than one Get statement

Custom method names in ASP.NET Web API

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