Passing route functions to HTML via Socket.io Websocket - node.js

Question

Heyo.
i have an websocket defined like this.
const express = require('express');
const app = express();
const http = require('http');
const { Server } = require('socket.io');
const cors = require('cors');
app.use(cors());
const server = http.createServer(app);
const io = new Server(server, {
cors: {
origin: "*",
method: ["GET", "POST", "PUT"],
},
});
io.on("connection", (socket) => {
console.log(`user connected: ${socket.id}`);
});
server.listen(3001, () => {
console.log("websocket online");
});
The following code is the function i want to pass to my frontend html via websocket, which is accessed by pressing an button on my frontend html.
app.get("/updateSomething", (req,res) {
//some code
}
My question would be: How do i tell my frontend to access that specific function from my node script via button click.
<button>DoSomething</button>

Answer 1

You can use JavaScript to emit to your socket.io server when you press that button.
For example in your client html:
<button id="doSomethingBtn">DoSomething</button>
<script>
const socket = io();
document.getElementById("doSomethingBtn").addEventListener("click", () => {
socket.emit("buttonClicked", 'someData');
});
</script>
and in your server handle this emit
io.on("connection", (socket) => {
console.log(`user connected: ${socket.id}`);
socket.on("buttonClicked", (someData) => {
console.log("button Clicked!")
// here you can do any code you want including running whatever is in your app.get
});
});
Please dont hesitate to make a comment if you dont understand soemthing or you need more help.