Call SignalR Core Hub method from Controller

Question

How can I call SignalR Core Hub method from Controller?
I am using ASP.NET Core 2.0 with Microsoft.AspNetCore.SignalR (1.0.0-alpha2-final).

I have windows service which communicate with Excel, SolidEdge ... When operation is complete it post request to my controller in ASP.NET Core application. Now I need to inform all clients connected to server with SignalR that external program completed some task.
I can not change the way window service works. (Can not connect to SignalR from window service).
I found plenty solution for old SignalR (GlobalHost.ConnectionManager.GetHubContext), but much has changed and those solutions are not working anymore.

My controller:

[Route("API/vardesigncomm")] public class VarDesignCommController : Controller {     [HttpPut("ProcessVarDesignCommResponse/{id}")]     public async Task<IActionResult> ProcessVarDesignCommResponse(int id)     {         //call method TaskCompleted in Hub !!!! How?          return new JsonResult(true);     } } 

My hub:

public class VarDesignHub : Hub {     public async Task TaskCompleted(int id)     {         await Clients.All.InvokeAsync("Completed", id);     } } 

Answer 1

Solution 1

Another possibility is to inject your HubContext into your controller like:

public VarDesignCommController(IHubContext<VarDesignHub> hubcontext) {     HubContext = hubcontext;     ... }  private IHubContext<VarDesignHub> HubContext { get; set; } 

Then you can also call

await this.HubContext.Clients.All.InvokeAsync("Completed", id); 

But then you will direct call methods on all clients.

Solution 2

You can also work with typed hubs: Simple create an interface where you define which methods your server can call on the clients:

public interface ITypedHubClient {     Task BroadcastMessage(string name, string message); } 

Inherit from Hub:

public class ChatHub : Hub<ITypedHubClient> {     public void Send(string name, string message)     {         Clients.All.BroadcastMessage(name, message);     } } 

Inject your the typed hubcontext into your controller, and work with it:

[Route("api/demo")] public class DemoController : Controller {     IHubContext<ChatHub, ITypedHubClient> _chatHubContext;     public DemoController(IHubContext<ChatHub, ITypedHubClient> chatHubContext)     {         _chatHubContext = chatHubContext;     }      // GET: api/values     [HttpGet]     public IEnumerable<string> Get()     {         _chatHubContext.Clients.All.BroadcastMessage("test", "test");         return new string[] { "value1", "value2" };     } }