Client config

The contractCopy Anchor Link

The hubs object is the contract. Each key is a hub path. Each value declares the events that the server pushes and the methods that you call on the server:

import { event, method } from "@dammers/use-signalr-angular";

export interface ChatMessage {
  roomId: string;
  user: string;
  text: string;
  sentAt: string;
}

// Keys are hub paths. Names and argument types match the server hub.
export const hubs = {
  "/hubs/rooms": {
    events: {
      MessageReceived: event<[message: ChatMessage]>(),
    },
    methods: {
      JoinRoom: method<[roomId: string]>(),
      LeaveRoom: method<[roomId: string]>(),
      SendMessage: method<[roomId: string, text: string]>(),
      GetHistory: method<[roomId: string], ChatMessage[]>(),
    },
  },
  "/hubs/presence": {
    lazy: true,
    graceMs: 2000,
    events: {
      OnlineCount: event<[count: number]>(),
    },
  },
};

event<Args>() takes the argument tuple of the handler. method<Args, Return>() takes the argument tuple and the type that the call resolves with. The default return type is void.

• A hub key must start with "/".
• A key that the hub definition does not know is a type error. This catches a typo such as graceMS.
• The method name must match the server method, including its casing. SignalR does not change the casing of method names.

Types flow from the contract. You write no separate contract type.

Create the clientCopy Anchor Link

createSignalRClient takes the contract and the options. Call it once, in a module that the rest of your app imports:

It returns provideSignalR and the typed helpers for your hubs.

import { createSignalRClient } from "@dammers/use-signalr-angular";
import { hubs } from "./contract";

export const {
  provideSignalR,
  injectHubEvent,
  injectHubInvoke,
  injectHubSend,
  injectHubTeardown,
  injectHubStatus,
  injectOnReconnected,
  injectKeepHubAlive,
} = createSignalRClient({ hubs });

Global and per-hub optionsCopy Anchor Link

You can set an option for all hubs, or for one hub. The value of a hub wins over the global value. These options are optional:

The library owns accessTokenFactory. Set it where you start the session, not in httpOptions.

This sample makes the presence hub lazy and sets its own reconnect delays:

const hubs = {
  "/hubs/rooms": {},
  "/hubs/presence": {
    lazy: true,
    graceMs: 2000,
    reconnect: [0, 2000, 10000],
  },
};

reconnect: false does not stop all retries. See Recovery.

Base URLCopy Anchor Link

The baseUrl is the root of your server. The library adds the hub path to it.

• The library removes a trailing slash. https://example.com/ and https://example.com give the same result.
• An empty string disables the session, so no hub connects. To use the same origin as the page, write "/".
• A change of baseUrl rebuilds all connections.

Keys that do not existCopy Anchor Link

createSignalRClient throws an error for these keys, at the top level or in a hub:

• transport and skipNegotiation. Put them in httpOptions.
• maxConnectRetries. The library retries a failed hub until the hub stops, so this option does not exist.

skipNegotiation: true needs transport: HttpTransportType.WebSockets. A binary protocol object with the Server-Sent Events transport also throws.