Socket.io Client Once
Socket.io Client once is a very simple package that allows you to avoid the multiple event listening issues associated with socket.io client library.
This simple library prevents multiple creation of socket listeners that grossly affect performance with SAP applications.
Creating socket client instance
This library similar interface with the traditional socket.io library, so it can be easily replaced any existing socket.io-client implementation, or so I thought.
import { io } from "socket.io-client-once";
const client = io("socket.io-url", {
// accept all socket.io client options
transports: ["websocket"],
autoConnect: true,
});
client.on("event-to-listen-to", (data: any) => {
// process response data
console.log(data);
});
client.emit("event-to-emit", {
// event data
});Event listener order
When you add multiple event listener of the same event, only the last listener will be processed. see the example below:
/**
* Despite adding multiple event listeners for the same event, only the last listener added
* will be processed.
*
* @note this allows us to avoid multiple instance listener scenario synonymous with
* socket.io client libraries. So our listener will only fire once
**/
client.on("event-to-listen-to", (data: any) => {
// This listener will not be processed
});
client.on("event-to-listen-to", (data: any) => {
// Only the last listener will be processed
});Getting the underlining socket.io client
To get the underlining socket.io client instance, you can use the following. This will enable you to perform any other task related traditional socket.io client