WebSocket-based Pub/Sub client and server, used for remote code execution and message passing in Flok.
- Basic Publish/Subscribe functionality:
subscribe,unsubscribe,publish,unsubscribeAll. - Payload is JSON serialized, topics are any string.
- Allows subscribing or unsubscribing without being connected by storing state on the client.
- Automatically reconnects if connection is lost, recovering client's state.
- Ping/pong mechanism for detecting and closing broken connections both on client and server.
import { WebSocketServer } from "ws"
import { PubSubServer } from "@flok-editor/pubsub"
// To use the server, you need to create a `WebSocketServer` and pass it to
// `PubSubServer`.
const wss = new WebSocketServer({ port: 4000 });
const server = new PubSubServer({ wss });
console.log(`PubSub server listening on`, wss.address())import { PubSubClient } from "@flok-editor/pubsub"
const client = new PubSubClient({ url: "ws://localhost:4000" });
// Subscribe to topics
client.subscribe("b");
client.subscribe("a");
client.start();
// Wait for the connection to be made, otherwise published messages are discarded.
let internalId;
client.on("open", () => {
// Publish a message (any JSON serializable object) to a topic
internalId = setInterval(() => {
client.publish("a", { salutation: "hello!" })
}, 2000);
})
// Add an error event handler to ignore connection errors
client.on("error", () => { });
client.on("close", () => clearInterval(internalId))
setTimeout(() => {
// Unsubscribe from a topic
client.unsubscribe("b");
// ... or from all topics with a single call
client.unsubscribeAll();
}, 5000)
// you can add a listener for all message events
client.on("message", (topic, data) => {
console.log("message", topic, data)
})
// ...or only from a specific topic
client.on("message:a", (data) => {
console.log("message from topic 'a'", data)
})
// Finally, you can subscribe and listen to messages in a single call
client.subscribe("c", (data) => {
console.log("message from 'c'", data);
});Run npm install to install dependencies.
Run npm run build to build package.