nichoth/nanobus

Tiny message bus

nanobus

Tiny message bus.

Usage

var nanobus = require('nanobus')
var bus = nanobus()

bus.on('foo', function (color) {
  console.log('color is', color)
})

bus.emit('foo', 'blue')

FAQ

Why not use the Node API?

We had the requirement for a * event to catch all calls, and figured we could improve the file size at the same time. This library is about 1/3rd the size of Node's version. And it was easy to build, so yeah good enough of an excuse hah.

How do I listen for replies?

You can do this by using the .once() listener and establishing a convention around naming schemas.

bus.on('foo', function (color) {
  console.log('foo called')
  bus.emit('foo:res')
})

bus.once('foo:res', function () {
  console.log('response received')
})
bus.emit('foo')

When shouldn't I use this package?

If you're only writing code that runs inside Node and don't need a '*' listener, consider using the built-in event emitter API instead.

Are the emitters asynchronous?

No. If you're interested in doing that, use something like nanotick to batch events and ensure they run asynchronously.

API

bus = nanobus([name])

Create a new nanobus instance. Optionally takes a name that will be used for tracing in the browser using the performance.mark / performance.measure API.

bus.emit(eventName, [data])

Emit an event. Arbitrary data can optionally be passed as an argument. '*' listeners run after named listeners.

bus.on(eventName, listener([data]))

bus.addListener(eventName, listener([data]))

Listen to an event. If the event name is '*' the listener signature is listener(eventName, [data], [performanceTimingId]).

bus.prependListener(eventName, listener([data]))

Listen to an event, but make sure it's pushed to the start of the listener queue. If the event name is '*' the listener signature is listener(eventName, [data]).

bus.once(eventName, listener([data]))

Listen to an event, and clear it after it's been called once. If the event name is '*' the listener signature is listener(eventName, [data], [performanceTimingId]).

bus.prependOnceListener(eventName, listener([data]))

Listen to an event, and clear it after it's been called once. If the event name is '*' the listener signature is listener(eventName, [data]).

bus.removeListener(eventName, listener)

Remove a specific listener to an event.

listeners = bus.listeners(eventName)

Return all listeners for a given event

bus.removeAllListeners([eventName])

Remove all listeners to an event. If no event name is passed, removes all listeners on the message bus.

License

MIT