Guide
WebSockets
H3 内置支持跨平台的 WebSocket 和服务器发送事件。
H3 使用 🔌 CrossWS 提供内置的、运行时无关的 WebSocket 支持。
h3 v2 对 WebSockets 的内置支持仍在开发中。
使用方法
websocket.mjs
import { H3, serve, proxy, defineWebSocketHandler } from "h3";
export const app = new H3();
const websocketDemoURL =
"https://raw.githubusercontent.com/unjs/crossws/main/examples/h3/public/index.html";
app.get("/", (event) =>
proxy(event, websocketDemoURL, { headers: { "Content-Type": "text/html" } }),
);
app.use(
"/_ws",
defineWebSocketHandler({
open(peer) {
console.log("[ws] open", peer);
},
message(peer, message) {
console.log("[ws] message", peer, message);
if (message.text().includes("ping")) {
peer.send("pong");
}
},
close(peer, event) {
console.log("[ws] close", peer, event);
},
error(peer, error) {
console.log("[ws] error", peer, error);
},
}),
);
serve(app);
服务器发送事件（SSE）
作为 WebSockets 的替代方案，您可以使用服务器发送事件。
H3 提供内置 API，可使用 createEventStream(event) 工具创建服务器发送事件。
示例
server-sent-events.mjs
import { H3, serve, createEventStream } from "h3";
export const app = new H3();
app.get("/", (event) => {
const eventStream = createEventStream(event);
// Send a message every second
const interval = setInterval(async () => {
await eventStream.push("Hello world");
}, 1000);
// cleanup the interval when the connection is terminated or the writer is closed
eventStream.onClosed(() => {
console.log("Connection closed");
clearInterval(interval);
});
return eventStream.send();
});
serve(app);