linus/Publish a message

## middleware.coffee
redis = require 'redis'

# Make sure multi-line messages are properly formatted
formatData = (data) ->
  data.split(/\n/).join "\ndata: "

# Format data as an event
formatEvent = (type, data) ->
  """
  id: #{+new Date}
  event: #{type}\n
  data: #{formatData data}

  """

# Stream events on redis channel to response
stream = (config, req, res) ->
  channel = req.url[1..]

  unless channel in req.user.auctions.concat req.user.username
    res.writeHead 403
    return res.end()

  res.writeHead 200,
    'content-type': 'text/event-stream'
    'cache-control': 'no-cache'
    'connection': 'keep-alive'
  res.write ''

  sub = redis.createClient config

  sub.on 'pmessage', (pattern, chan, message) ->
    type = chan.slice channel.length
    res.write formatEvent type, message

  sub.psubscribe channel + '*'

  finish = (err) ->
    console.error err if err

    sub.quit()
    res.end()

  req.on 'close', finish
  req.on 'error', finish

# SSE middleware
module.exports = (config) ->
  (req, res, next) ->
    if req.accepts 'event-stream'
      stream config, req, res
    else
      next()

## Publish a message
linus@Newton:~$ redis-cli
redis 127.0.0.1:6379> publish /updates.foo "hello there!"
(integer) 1
redis 127.0.0.1:6379>

## sse.coffee
http = require 'http'
redis = require 'redis'

# Send data as an event of optional type
sendEvent = (res, data, type) ->
  # Make sure multi-line messages are properly formatted
  formatData = (data) ->
    data.split(/\n/).join "\ndata: "

  res.write "id: #{+new Date}\n"
  res.write "event: #{type}\n" if type
  res.write "data: #{formatData data}\n\n"

# Handle event-stream requests
sendEvents = (req, res) ->
  # Write header
  res.writeHead 200,
    'content-type': 'text/event-stream'
    'cache-control': 'no-cache'
    'connection': 'keep-alive'

  res.write '' # Flush headers

  # Subscribe to redis channels matching the request url
  sub = redis.createClient()
  channels = "#{req.url}.*"

  sub.psubscribe channels

  # Message handler
  sub.on 'pmessage', (pattern, channel, message) ->
    # Type is the last part of the channel name
    type = channel.split(".").pop()

    sendEvent res, message, type

  finish = (err) ->
    console.error err if err

    sub.quit()
    res.end()

  # Clean up when request is closed
  req.on 'close', finish
  req.on 'error', finish

# Send the page
sendPage = (req, res) ->
  res.writeHead 200, 'content-type': 'text/html'
  res.end """<!doctype html>
    <html>
      <head>
        <script>
          var logger = function(channel) {
            return function(message) {
              var data = message.data || message;
              console.log(channel + ": ", data);
            }
          };
          var messages = new EventSource("updates");
          messages.onopen = logger("open");
          messages.onerror = logger("error");
          messages.onmessage = logger("message");
          messages.addEventListener("foo", logger("foo"), false);
          messages.addEventListener("bar", logger("bar"), false);
        </script>
      </head>
      <body>hai</body>
    </html>
  """

# Create our app
app = http.createServer (req, res) ->
  if req.headers.accept is 'text/event-stream'
    sendEvents req, res
  else
    sendPage req, res

app.listen 8000
	redis = require 'redis'

	# Make sure multi-line messages are properly formatted
	formatData = (data) ->
	data.split(/\n/).join "\ndata: "

	# Format data as an event
	formatEvent = (type, data) ->
	"""
	id: #{+new Date}
	event: #{type}\n
	data: #{formatData data}

	"""

	# Stream events on redis channel to response
	stream = (config, req, res) ->
	channel = req.url[1..]

	unless channel in req.user.auctions.concat req.user.username
	res.writeHead 403
	return res.end()

	res.writeHead 200,
	'content-type': 'text/event-stream'
	'cache-control': 'no-cache'
	'connection': 'keep-alive'
	res.write ''

	sub = redis.createClient config

	sub.on 'pmessage', (pattern, chan, message) ->
	type = chan.slice channel.length
	res.write formatEvent type, message

	sub.psubscribe channel + '*'

	finish = (err) ->
	console.error err if err

	sub.quit()
	res.end()

	req.on 'close', finish
	req.on 'error', finish

	# SSE middleware
	module.exports = (config) ->
	(req, res, next) ->
	if req.accepts 'event-stream'
	stream config, req, res
	else
	next()
	linus@Newton:~$ redis-cli
	redis 127.0.0.1:6379> publish /updates.foo "hello there!"
	(integer) 1
	redis 127.0.0.1:6379>
	http = require 'http'
	redis = require 'redis'

	# Send data as an event of optional type
	sendEvent = (res, data, type) ->
	# Make sure multi-line messages are properly formatted
	formatData = (data) ->
	data.split(/\n/).join "\ndata: "

	res.write "id: #{+new Date}\n"
	res.write "event: #{type}\n" if type
	res.write "data: #{formatData data}\n\n"

	# Handle event-stream requests
	sendEvents = (req, res) ->
	# Write header
	res.writeHead 200,
	'content-type': 'text/event-stream'
	'cache-control': 'no-cache'
	'connection': 'keep-alive'

	res.write '' # Flush headers

	# Subscribe to redis channels matching the request url
	sub = redis.createClient()
	channels = "#{req.url}.*"

	sub.psubscribe channels

	# Message handler
	sub.on 'pmessage', (pattern, channel, message) ->
	# Type is the last part of the channel name
	type = channel.split(".").pop()

	sendEvent res, message, type

	finish = (err) ->
	console.error err if err

	sub.quit()
	res.end()

	# Clean up when request is closed
	req.on 'close', finish
	req.on 'error', finish

	# Send the page
	sendPage = (req, res) ->
	res.writeHead 200, 'content-type': 'text/html'
	res.end """<!doctype html>
	<html>
	<head>
	<script>
	var logger = function(channel) {
	return function(message) {
	var data = message.data \|\| message;
	console.log(channel + ": ", data);
	}
	};
	var messages = new EventSource("updates");
	messages.onopen = logger("open");
	messages.onerror = logger("error");
	messages.onmessage = logger("message");
	messages.addEventListener("foo", logger("foo"), false);
	messages.addEventListener("bar", logger("bar"), false);
	</script>
	</head>
	<body>hai</body>
	</html>
	"""

	# Create our app
	app = http.createServer (req, res) ->
	if req.headers.accept is 'text/event-stream'
	sendEvents req, res
	else
	sendPage req, res

	app.listen 8000