I am developing ASP.NET Web API using .NET Core. This Web API is going to be mainly accessed by UI application (UI will be developed using ASP.NET Core MVC) but in future API ma
Have a look at swagger: https://docs.microsoft.com/en-us/aspnet/core/tutorials/web-api-help-pages-using-swagger It's better to specify ProducesResponseType attribute for method:
[ProducesResponseType(typeof(TodoItem), 201)]
public IActionResult Create([FromBody, Required] TodoItem item)
So that automatically generated swagger documentation to show the actual returned data for the method.
If I want [the] client to do content negotiation then what should be the return type of the API action method?
To do content negotiation, return Task<ObjectResult>
or Task<MyPoco>
.
The framework automatically wraps POCOs in an ObjectResult
; therefor, both options are equivalent, and both will obey the HTTP Accept
header. You will also get content negotiation by returning any result that implements ObjectResult
, such as an OkObjectResult
does.
If I want [the] method to always return data in JSON format then what should be [the] return type of the API action method?
To always return JSON, return a Task<JsonResult>
(or use the [Produces]
filter).
See also: https://docs.asp.net/en/latest/mvc/models/formatting.html#content-negotiation
[S]o I am assuming then
IActionResult
is only used for MVC controller?
IActionResult
is the contract for all results that a Controller
returns. If your action's signature has an IActionResult
return type, then your action's method body can return
any result type, because all of them implement the IActionResult
interface. Here is the inheritance hierarchy.
IActionResult
ActionResult
ChallengeResult
ContentResult
EmptyResult
FileResult
FileContentResult
FileStreamResult
PhysicalFileResult
VirtualFileResult
ForbidResult
LocalRedirectResult
ObjectResult
CreatedAtActionResult
CreatedAtRouteResult
CreatedResult
BadRequestObjectResult
NotFoundObjectResult
OkObjectResult
RedirectResult
RedirectToActionResult
RedirectToRouteResult
SignInResult
SignOutResult
StatusCodeResult
NoContentResult
NotFoundResult
OkResult
UnauthorizedResult
UnsupportedMediaTypeResult
BadRequestResult
See also: https://github.com/aspnet/Mvc/tree/dev/src/Microsoft.AspNetCore.Mvc.Core