express-sse-middleware

It's a Express middleware that simply and easily using Server Sent Events (SSE)

Installation

npm install express-sse-middleware

How to use

Simple Usage

import express from 'express';
import { sseMiddleware } from 'express-sse-middleware';

app.use(sseMiddleware);
app.get('/path', (req, res) => {
  const sse = res.sse(); // `adding Response.sse()` funciton

  let count = 0;
  setInterval(() => {
    sse.send(String(count++));
  }, 1000);
  
  // sent incremented number every second.
  // ↓
  // data: 0
  // data: 1
  // data: ...

});

app.listen(3000);

EventBuilder

Prepared a simple event builder. but params of send function is so simple that No need to use.

  let count = 0;
  const builder = new EventBuilder() // <- Builder instance is immutable.
                        .id('test_id')
                        .event('event_name');
  setInterval(() => {
    sse.send(builder.data(String(count++)).build());
  }, 1000);

  // ↓
  // id: test_id
  // event: event_name
  // data: 0
  // 
  // id: test_id
  // event: event_name
  // data: 1

Dependency

This middleware is not depend on anything.