SSESource

The @codecat/sse library provides an easy and efficient way to handle Server-Sent Events (SSE) in JavaScript and TypeScript. It includes tools for both fetching and pushing events from/to the server.

• Fetching Events: The SSESource class allows you to connect to an SSE endpoint, handle events individually or in a loop, and gracefully manage connection closures.
• Pushing Events: The SSESink class facilitates sending events from the server to connected clients, making it simple to implement real-time updates in your application.

The library supports custom HTTP methods, headers, and request bodies, offering flexibility for various use cases.

Usage

Fetching events from the server

import { SSESource } from 'jsr:@codecat/sse';

const source = new SSESource('https://example.com/sse', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer token',
  },
  body: JSON.stringify({ key: 'value' }),
});

try {
  // Handling events one by one
  const { event, done } = await source.next();
  console.log('connection closed: ', done);
  if (!done) {
    console.log(event.data);
  }

  // Handling events in a loop
  for await (const event of source) {
    console.log(event.data);
  }
  console.log('connection closed');
} catch (e) {
  console.error(e);
}

Pushing events on the server

import { SSESink } from 'jsr:@codecat/sse';

Deno.serve((req) => {
  if (req.method === 'GET' && req.url === '/sse') {
    const sink = new SSESink();
    setInterval(() => {
      sink.sendMessage({ data: 'Hello, world!' });
    }, 1000);
    return sink.getResponse();
  }
  return Response.error();
});

License

MIT License

Copyright (c) 2024 Mateusz Russak