Takes Express/Connect routes and creates stream.Writable endpoints for Server Sent Events.
SSEriesOfTubes attaches to an http.Server and efficiently manages each endpoint for Server Sent Events by creating a writeable StringTube Stream that is piped to every http.Response. StringTube is a utf8 String Stream subclassed from Through2.
Additionally, SSEriesOfTubes can wrap a standard Express/Connect route controller (a function that takes arguments (req, res, next)), poll that controller for data, and push that data to the SSE stream.
This way, any API can easily support REST/polling and Server Sent Events with the same route controller.
SSEriesOfTubes is an EventEmitter based on chrisdickinson/sse-stream, so it handles SSE headers, keep-alive messaging, and emits events around the connection and polling lifecycle.
npm install --save sseries-of-tubes# on server
http = require "http"
express = require "express"
SSEriesOfTubes = require "sseries-of-tubes"
server = new http.Server
app = express()
sseriesOfTubes = new SSEriesOfTubes server
sendHello = (req, res, next) ->
res.json hello: "world"
# Sends {"hello": "world"} every 3s to every client connected to /sse/hello
app.get "/sse/hello", sseriesOfTubes.plumb sendHello, 3
...
# on client
source = new EventSource "/sse/hello"
# log {"hello": "world"} as received every 3s
source.onmessage = (data) -> console.log data
Pointer to class StringTube, a Through2 Readable/Writable stream.
new SSEriesOfTubes http.Server server, int keepAliveIntervalreturns sseriesOfTubes instance
Creates a new SSEriesOfTubes instance that reacts to http.Server "listening" and "close" events.
sseriesOfTubes.plumb Function route, int intervalreturns Function route
Creates a new StringTube source which polls a route to write to all clients for an endpoint.
sseriesOfTubes.plumb Function route, int interval, String eventreturns Function route
Creates a new StringTube source which polls a route to write to all clients for an endpoint, and will send the event event (in EventSource syntax) before sending data.
sseriesOfTubes.plumb()returns Function route
Creates a new StringTube source which writes to all clients for an endpoint.
sseriesOfTubes.source String urlreturns StringTube source
Retrieves the StringTube source for an endpoint.
sseriesOfTubes.combine express.Router router, String paths...returns Function route
Creates a new StringTube source by combining existing StringTube sources referenced by their path. This way different combinations of streams can be provided without duplicating pollers. Requires a router conforming to the express.Router interface for method handle.
sseriesOfTubes.multiplex express.Router router, String paramreturns Function route
Creates new StringTube sources by dynamically combining existing StringTube sources, referenced by their path in an comma-separated list provided by the client in the query or body as parameter param. This method is similar to combine, but works with paths that have route parameters. Requires a router conforming to the express.Router interface for method handle.
sseriesOfTubes.destroy()Ends all SSE client connections and destroys all clients.
sseriesOfTubes.on "connection", (client) ->On client connection, calls bound function with an instance of Client.
sseriesOfTubes.on "poll", (url) ->On route start poll, calls bound function with the url endpoint.
sseriesOfTubes.on "plumb", (url) ->On route start plumb (creates StringTube source), calls bound function with the url endpoint.
sseriesOfTubes.on "stop", (url) ->On last client disconnect, calls bound function with the url endpoint.
MIT