shoe

Streaming sockjs for node and the browser.

This is a more streaming, more unixy take on sockjs.

works with browserify (modularity)
stream all the things (composition)
emits a 'log' event instead of spamming stdout (silence)

shoe point javascript

example

stream all the things

Browser code that takes in a stream of 0s and 1s from the server and inverts them:

var shoe = require('shoe');
var through = require('through');

var result = document.getElementById('result');

var stream = shoe('/invert');
stream.pipe(through(function (msg) {
    result.appendChild(document.createTextNode(msg));
    this.queue(String(Number(msg)^1));
})).pipe(stream);

Server code that hosts some static files and emits 0s and 1s:

var shoe = require('shoe');
var http = require('http');

var ecstatic = require('ecstatic')(__dirname + '/static');

var server = http.createServer(ecstatic);
server.listen(9999);

var sock = shoe(function (stream) {
    var iv = setInterval(function () {
        stream.write(Math.floor(Math.random() * 2));
    }, 250);
    
    stream.on('end', function () {
        clearInterval(iv);
    });
    
    stream.pipe(process.stdout, { end : false });
});
sock.install(server, '/invert');

The server emits 0s and 1s to the browser, the browser inverts them and sends them back, and the server dumps the binary digits to stdout.

By default, there's no logspam on stdout to clutter the output, which is a frustrating trend in realtimey websocket libraries that violates the rule of silence.

Just wait for a client to connect and you'll see:

$ node server.js
001011010101101000101110010000100

with dnode

Since dnode has a simple streaming api it's very simple to plug into shoe.

Just hack up some browser code:

var shoe = require('shoe');
var dnode = require('dnode');

var result = document.getElementById('result');
var stream = shoe('/dnode');

var d = dnode();
d.on('remote', function (remote) {
    remote.transform('beep', function (s) {
        result.textContent = 'beep => ' + s;
    });
});
d.pipe(stream).pipe(d);

and hack up a server piping shoe streams into dnode:

var shoe = require('shoe');
var dnode = require('dnode');

var http = require('http');
var ecstatic = require('ecstatic')(__dirname + '/static');

var server = http.createServer(ecstatic);
server.listen(9999);

var sock = shoe(function (stream) {
    var d = dnode({
        transform : function (s, cb) {
            var res = s.replace(/[aeiou]{2,}/, 'oo').toUpperCase();
            cb(res);
        }
    });
    d.pipe(stream).pipe(d);
});
sock.install(server, '/dnode');

Then open up localhost:9999 in your browser and you should see:

beep => BOOP

with express or connect

you must pass the return value of app.listen(port)

var shoe = require('shoe');

var express = require('express')
var app = express()

var sock = shoe(function (stream) { ... });

// *** must pass expcess/connect apps like this:
sock.install(app.listen(9999), '/dnode');

with reconnect

you can use reconnect just in case your sock ends or gets disconnected.

var shoe = require('shoe');
var reconnect = require('reconnect');
var es = require('event-stream');
var result = document.getElementById('result');

var r = reconnect(function (stream) {

  var s = es.mapSync(function (msg) {
      result.appendChild(document.createTextNode(msg));
      return String(Number(msg)^1);
  });
  s.pipe(stream).pipe(s);

}).connect('/invert')

browser methods

var shoe = require('shoe')

var stream = shoe(uri, cb)

Return a readable/writable stream from the sockjs path uri. uri may be a full uri or just a path.

shoe will emit a 'connect' event when the connection is actually open, (just like in net). writes performed before the 'connect' event will be buffered. passing in cb to shoe is a shortcut for shoe(uri).on('connect', cb)

server methods

var shoe = require('shoe')

All the methods from the sockjs exports objects are attached onto the shoe function, but the shoe() function itself is special.

var sock = shoe(opts, cb)

Create a server with sockjs.createServer(opts) except this function also adds the .install() function below.

If cb is specified, it fires cb(stream) on 'connection' events.

sock.install(server, opts)

Call sock.installHandler() with the default option of spamming stdout with log messages switched off in place of just emitting 'log' messages on the sock object instead. This is a much less spammy default that gets out of your way.

If opts is a string, use it as the opts.prefix.

server events

All the messages that sockjs normally emits will be available on the sock object plus the events below:

sock.on('log', function (severity, msg) { ... })

Using the default logger with sock.install() will cause these 'log' messages to be emitted instead of spamming stdout.

install

With npm do:

npm install shoe