node package manager
Share your code. npm Orgs help your team discover, share, and reuse code. Create a free org »



A hub for centralizing all your request handlers within your application. Implements the disposable pattern.


npm install transport

How to use

Require and initialize transport:

var Transport = require("transport"),
  transport = new Transport();


Define a simpleHandler to handle a request and send the result back:

// Object with all the request handlers 
var handlers = {
    simpleHandler: function (payload, callback) {
        // do something with the payload 
        var result = doSomethingWithPayload(payload);
        // send the result back 

Add the handler to Transport. The handlers have to be stored in an observable-store. This allows for sharing the same handlers between several implementations of Transport and react accordingly when handlers are added and removed.

var Store = require("observable-store");
transport.setReqHandlers(new Store(handlers));

Make the request to simpleHandler:

transport.request("simpleHandler", "payload", function callback(result) {
    // do something with result 

Open a channel

Let's define a handler that will publish several updates.

var handlers = {
    simpleChannel: function (payload, onEnd, onData) {
        var stream = getStream(payload);
        stream.on('data', onData);
        stream.on('end', onEnd);

Now we can open the channel and receive updates:

transport.listen("simpleChannel", "filename", function onEnd(data) {
    // Will be called when stream closes 
    console.log("END OF FILE", data);
}, function onData(data) {
    // Will be called everytime some data is pushed 
    console.log("MORE DATA", data);

Close/dispose an open channel

transport.listen returns a function. When the handler also returns a function, it will be called by executing the one returned by transport.listen. It can be used to stop whatever the handler started and do some cleanup too.

var handlers = {
    closableChannel: function (payload, onEnd, onData) {
        var stream = getStream(payload);
        stream.on("data", onData);
        stream.on("end", onEnd);
        return function stop() {
            stream.removeListener("data", onData);
            stream.removeListener("end", onEnd);

Now, when calling transport.listen, we can call the stop() function returned by the handler.

var stop = transport.listen("closableChannel", "filename", function onEnd() { ... }, function onData() { ... });
// When calling stop, the stop() function returned by the handler will be executed. 

Managing errors

A convenient way to bubble up errors is to follow the error first convention:

var handlers = {
    closableChannel: function (payload, onEnd, onData) {
        var stream = getStream(payload);
        stream.on("data", onData);
        stream.on("end", function (data) {
            onEnd(null, data);
        stream.on("error", function (error) {

And now we can handle the errors in the onEnd callback.

transport.listen("closableChannel", "filename", function onEnd(error, data) {
    if (error) {
        throw new Error(error);
    // do something with data 
}, function onData() {
        // ...