Adding a client-side method on the proxy and calling it from the server

The previous recipe taught us how to call a server-side method exposed by a Hub and how to receive its return value, if any. As we already explained in Chapter 2, Using Hubs, SignalR really shines when we have to push information to several connected clients at the same time, and we illustrated the various APIs available to do this. In this recipe, we'll concentrate again on those strategies, and in particular on notifying the caller, but our focus will be on explaining the client-side mechanics involved when receiving server-to-client calls.

How to do it…

We need to prepare our Hub, and to do this we need to perform the following steps:

1. Add a Hub-derived type that we'll call EchoHub.

2. Add an OWIN Startup class bootstrapping SignalR with a call to app.MapSignalR(); inside its Configuration() method.

For more details on these steps, you can check the previous chapters.

Then, let's start adding the code for this specific sample...