WebSockets für Subscriptions einrichten
Konfigurieren Sie einen WebSocket-Server und integrieren Sie ihn in Ihr tRPC-Backend, um Echtzeitkommunikation zu ermöglichen.
WebSockets für Subscriptions einrichten ist eine kostenlose tRPC End-to-End Type Safe APIs-Lektion auf CoddyKit. Dies ist Lektion 2 von 4. Du kannst die komplette Lektion unten kostenlos lesen – dann übst du sie direkt im Browser mit einem integrierten Code-Editor und einem KI-Tutor rund um die Uhr. Sie ist Teil des tRPC End-to-End Type Safe APIs-Lernpfads, und dein Fortschritt wird über Web und CoddyKit-App synchronisiert. Der tRPC End-to-End Type Safe APIs-Kurs umfasst insgesamt 4 Lektionen.
Teile dieser Lektion wurden noch nicht übersetzt und werden auf Englisch angezeigt.
Real-time with WebSockets
When building modern web applications, real-time updates are often essential. Think of live chat, stock tickers, or notification systems.
Traditional HTTP requests are stateless and short-lived. WebSockets provide a persistent, bidirectional communication channel between a client and a server.
- Persistent: The connection stays open, unlike HTTP.
- Bidirectional: Both client and server can send messages at any time.
- Efficient: Less overhead than constantly polling via HTTP.
Basic WebSocket Server Setup
Before integrating tRPC, let's understand how a standalone WebSocket server works. We'll use the popular ws library for Node.js.
First, install the necessary packages: npm install ws typescript ts-node
This basic server listens for connections and logs when clients connect or send messages.
import ws from 'ws';
const wss = new ws.Server({ port: 3001 });
wss.on('connection', (socket) => {
console.log('Client connected to raw WS!');
socket.on('message', (message) => {
console.log(`Received: ${message}`);
socket.send(`Echo: ${message}`);
});
socket.on('close', () => {
console.log('Client disconnected from raw WS!');
});
socket.send('Welcome to the raw WS server!');
});
console.log('Raw WS server listening on ws://localhost:3001');tRPC's WebSocket Adapter
tRPC needs a way to communicate over the WebSocket protocol. That's where @trpc/server/adapters/ws comes in.
This adapter allows your tRPC procedures to be exposed and handled by an existing WebSocket server (like the ws server we just saw).
Install it: npm install @trpc/server @trpc/server/adapters/ws
Preparing Your tRPC Router
For tRPC to handle subscriptions over WebSockets, you need a tRPC router and a context factory. This is similar to setting up an HTTP API, but for real-time communication.
Let's define a minimal tRPC setup. We'll add a simple subscription procedure next.
import { initTRPC } from '@trpc/server';
// Create a tRPC instance
const t = initTRPC.create();
// Define your application router
export const appRouter = t.router({
// This will hold our subscription procedures
healthcheck: t.procedure.query(() => 'ok'),
});
// Export the router's type for client-side usage
export type AppRouter = typeof appRouter;
// Context factory (can be empty for now)
export const createContext = () => ({});Integrating tRPC with the WS Server
Now, let's combine our ws server with the tRPC router using the applyWSSHandler function from the adapter.
This function bridges your tRPC procedures to the WebSocket connection, making them available for real-time interaction.
wss: Your WebSocket server instance.router: Your tRPCappRouter.createContext: A function to create the tRPC context for each request.
import { applyWSSHandler } from '@trpc/server/adapters/ws';
import ws from 'ws';
import { appRouter, createContext } from './trpc'; // Assuming trpc.ts from previous scene
const wss = new ws.Server({ port: 3001 });
const handler = applyWSSHandler({
wss,
router: appRouter,
createContext,
});
wss.on('connection', (socket) => {
console.log(`tRPC WS client connected! Total: ${wss.clients.size}`);
socket.once('close', () => {
console.log(`tRPC WS client disconnected! Total: ${wss.clients.size}`);
});
});
console.log('tRPC WS server listening on ws://localhost:3001');
// Optional: Handle graceful shutdown
process.on('SIGTERM', () => {
console.log('SIGTERM received, closing WS server');
handler.broadcastReconnectNotification(); // Notify clients to reconnect
wss.close();
});Creating a Simple Subscription
tRPC subscriptions use the observable pattern. An observable is a stream of data that a client can subscribe to, receiving updates over time.
Here, we create a basic onHello subscription that immediately sends a greeting and then cleans up.
// Inside your trpc.ts (update appRouter definition)
import { observable } from '@trpc/server/observable';
export const appRouter = t.router({
healthcheck: t.procedure.query(() => 'ok'),
onHello: t.procedure.subscription(() => {
return observable<string>((emit) => {
// Send a message immediately when subscribed
emit.next('Hello from tRPC WebSocket!');
// This function runs when the client unsubscribes
return () => {
console.log('Client unsubscribed from onHello');
};
});
}),
});Full tRPC WebSocket Server Code
Here's the complete server-side setup. You can save this as server.ts and run it with ts-node server.ts.
It combines the tRPC router with a subscription, the ws server, and the integration via applyWSSHandler.
import { initTRPC } from '@trpc/server';
import { applyWSSHandler } from '@trpc/server/adapters/ws';
import ws from 'ws';
import { observable } from '@trpc/server/observable';
// 1. tRPC Setup
const t = initTRPC.create();
const appRouter = t.router({
healthcheck: t.procedure.query(() => 'ok'),
onHello: t.procedure.subscription(() => {
return observable<string>((emit) => {
emit.next('Hello from tRPC WebSocket!');
return () => { /* optional cleanup */ };
});
}),
});
export type AppRouter = typeof appRouter;
const createContext = () => ({});
// 2. WebSocket Server Setup
const wss = new ws.Server({ port: 3001 });
// 3. Integrate tRPC with WS Server
const handler = applyWSSHandler({
wss,
router: appRouter,
createContext,
});
wss.on('connection', (socket) => {
console.log(`Client connected! Total: ${wss.clients.size}`);
socket.once('close', () => {
console.log(`Client disconnected! Total: ${wss.clients.size}`);
});
});
console.log('tRPC WebSocket Server listening on ws://localhost:3001');
// 4. Graceful shutdown
process.on('SIGTERM', () => {
console.log('SIGTERM received, closing WS server');
handler.broadcastReconnectNotification();
wss.close();
});Client-Side WebSocket Link
On the client-side, you need to configure your tRPC client to use the WebSocket connection. This is done with wsLink from @trpc/client/links/wsLink.
The wsLink tells your tRPC client where to connect for real-time data, distinct from your HTTP endpoint.
Install: npm install @trpc/client @trpc/react-query @tanstack/react-query
import { createWSClient, wsLink, httpBatchLink, createTRPCReact } from '@trpc/react-query';
import type { AppRouter } from '../server/server'; // Adjust path to your server's AppRouter
// Create a tRPC React client instance
export const trpc = createTRPCReact<AppRouter>();
// Create a WebSocket client instance
const wsClient = createWSClient({
url: `ws://localhost:3001`,
});
export const trpcClient = trpc.createClient({
links: [
// Use the WebSocket link for subscriptions
wsLink({
client: wsClient,
}),
// Optionally, use HTTP for queries/mutations
httpBatchLink({
url: `http://localhost:3000/api/trpc`,
}),
],
});Consuming Subscriptions in Frontend
With the client configured, you can now use tRPC's useSubscription hook (if using React Query) to listen for real-time updates.
It works similarly to queries and mutations, but for continuous data streams, providing callbacks for new data and errors.
import React from 'react';
import { trpc } from './trpcClient'; // Assuming trpcClient.ts from previous scene
function MyComponent() {
const [message, setMessage] = React.useState('Waiting for greeting...');
// Subscribe to the 'onHello' procedure
trpc.onHello.useSubscription(undefined, {
onData(data) {
// This callback fires whenever the server sends new data
setMessage(data);
console.log('Received subscription data:', data);
},
onError(err) {
console.error('Subscription error:', err);
setMessage(`Error: ${err.message}`);
},
});
return (
<div>
<h1>Live Greeting:</h1>
<p>{message}</p>
</div>
);
}
export default MyComponent;Quick Check: WS Integration
You've learned how to set up a WebSocket server and integrate it with tRPC for real-time subscriptions. Which of the following are essential components or steps for this integration?
Recap: Setting Up WebSockets
You've successfully set up the foundation for real-time communication with tRPC!
- We started with a basic WebSocket server using the
wslibrary. - Then, we integrated our tRPC router with this server using
@trpc/server/adapters/wsandapplyWSSHandler. - We added a simple subscription procedure to our router using the
observablepattern. - Finally, we configured the client with
wsLinkand saw how to consume subscriptions usinguseSubscription.
This robust setup allows your tRPC backend to push real-time updates directly to your frontend clients, leveraging type safety end-to-end.
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Ist die Lektion „WebSockets für Subscriptions einrichten“ kostenlos?
Ja — der vollständige Text von „WebSockets für Subscriptions einrichten“ ist hier im Web kostenlos zu lesen. Um sie interaktiv zu üben (integrierter Code-Editor und 24/7 KI-Tutor) und den Rest des tRPC End-to-End Type Safe APIs-Kurses freizuschalten, upgrade auf CoddyKit PRO. Der tRPC End-to-End Type Safe APIs-Kurs umfasst insgesamt 4 Lektionen.
Was lerne ich in „WebSockets für Subscriptions einrichten“?
Konfigurieren Sie einen WebSocket-Server und integrieren Sie ihn in Ihr tRPC-Backend, um Echtzeitkommunikation zu ermöglichen. Du übst tRPC End-to-End Type Safe APIs mit praktischem Code, den du direkt im Browser ausführst, und ein 24/7 KI-Tutor beantwortet deine Fragen während du die Lektion bearbeitest.
Brauche ich Erfahrung, um tRPC End-to-End Type Safe APIs zu starten?
Keine Vorkenntnisse erforderlich. tRPC End-to-End Type Safe APIs auf CoddyKit ist für Anfänger bis fortgeschrittene Lernende strukturiert, sodass du hier starten oder von Anfang an beginnen und in deinem eigenen Tempo voranschreiten kannst. Dies ist Lektion 2 von 4.
Wie lange dauert die Lektion „WebSockets für Subscriptions einrichten“?
Die meisten CoddyKit-Lektionen dauern etwa 5–10 Minuten. Jede ist kompakt und interaktiv, sodass du stetig Fortschritte machst und genau dort weitermachst, wo du aufgehört hast – im Web und in der App.
Kann ich in dieser tRPC End-to-End Type Safe APIs-Lektion Code schreiben und ausführen?
Ja. Jede tRPC End-to-End Type Safe APIs-Lektion enthält einen integrierten Code-Editor, sodass du echten Code direkt in deinem Browser schreibst und ausführst und sofort KI-Feedback erhältst — ohne lokale Einrichtung erforderlich.
Alle Lektionen in diesem Kurs
- Einführung in Echtzeitkommunikation mit tRPC
- WebSockets für Subscriptions einrichten
- Live-Daten-Subscriptions implementieren
- Wiederverbindung und Bereinigung von Subscriptions