smashingpat/index.html

## index.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>SSE</title>
</head>
<body>
    <script>
        function startConnection() {
            const stream = new EventSource('/event-stream')

            stream.addEventListener('message', (event) => {
                console.log('[SSE]:', JSON.parse(event.data))
            })
            stream.addEventListener('open', () => {
                console.log('[SSE]: connected')
            })
        }

        startConnection()
    </script>
</body>
</html>

## server.js
const fs = require('fs')
const path = require('path')
const {
    createServer
} = require('http')

let requestCounter = 0

function handler(request, response) {
    requestCounter++
    const requestCount = requestCounter

    switch (request.url) {
        case '/event-stream':
            {
                console.log(`[SSE]: connection opened (${requestCount})`)
                response.writeHead(200, {
                    'Content-Type': 'text/event-stream',
                    'Connection': 'keep-alive',
                    'Cache-Control': 'no-cache'
                })
                response.write('\n\n')
                const intervalId = setInterval(() => {
                    response.write(`data: <my data here>`)
                    response.write('\n\n')
                }, 1000)

                response.on('close', () => {
                    console.log(`[SSE]: connection closed (${requestCount})`)
                    clearInterval(intervalId)
                })
                break
            }
        case '/':
            {
                response.writeHead(200, {
                    'Content-Type': 'text/html'
                })
                fs.createReadStream(path.resolve(__dirname, './index.html'))
                .pipe(response)
                break
            }
        default:
            {
                response.writeHead(404, {
                    'Content-Type': 'text/plain'
                })
                response.end('404 - Not Found')
                break
            }
    }
}

createServer(handler)
    .listen(4000, () => console.log('server listening'))
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>SSE</title>
	</head>
	<body>
	<script>
	function startConnection() {
	const stream = new EventSource('/event-stream')

	stream.addEventListener('message', (event) => {
	console.log('[SSE]:', JSON.parse(event.data))
	})
	stream.addEventListener('open', () => {
	console.log('[SSE]: connected')
	})
	}

	startConnection()
	</script>
	</body>
	</html>
	const fs = require('fs')
	const path = require('path')
	const {
	createServer
	} = require('http')

	let requestCounter = 0

	function handler(request, response) {
	requestCounter++
	const requestCount = requestCounter

	switch (request.url) {
	case '/event-stream':
	{
	console.log(`[SSE]: connection opened (${requestCount})`)
	response.writeHead(200, {
	'Content-Type': 'text/event-stream',
	'Connection': 'keep-alive',
	'Cache-Control': 'no-cache'
	})
	response.write('\n\n')
	const intervalId = setInterval(() => {
	response.write(`data: <my data here>`)
	response.write('\n\n')
	}, 1000)

	response.on('close', () => {
	console.log(`[SSE]: connection closed (${requestCount})`)
	clearInterval(intervalId)
	})
	break
	}
	case '/':
	{
	response.writeHead(200, {
	'Content-Type': 'text/html'
	})
	fs.createReadStream(path.resolve(__dirname, './index.html'))
	.pipe(response)
	break
	}
	default:
	{
	response.writeHead(404, {
	'Content-Type': 'text/plain'
	})
	response.end('404 - Not Found')
	break
	}
	}
	}

	createServer(handler)
	.listen(4000, () => console.log('server listening'))