The Bookshelf plugin that translates bookshelf events to a central hub. By default that hub is a bookshelf instance itself. That's useful if you want to subscribe to an event but don't want to modify model or collection initializer.

Signals = require 'bookshelf-signals'
db = bookshelf(knex)
db.plugin Signals()
class User extend db.Model
  tabeName: 'users'
db.on 'saved', User, ->
  console.log 'user was saved!'

db.plugin Signals(hub)

Argument passed to plugin is a hub to that all bookshelf events will be translated. It should at least implement methods trigger and triggerThen. If undefined then events will be translated to bookshelf instance and required methods will be added to it.

Default hub implementation has a behaviour different from EventEmitter. Its methods on, addListener, once, off, removeListener, removeAllListeners accepts class or model/collection name as a second parameter and performs events filtration according to it.

Methods:

• on(String event, [(Class|String) cls], Function handler)

  Subscribe to event with optional filtration by source class.

• addListener - alias for on

• removeListener(String event, [(Class|String) cls], Function handler)

  Unsubscribe from event. If class/name was used for subscription you have to use the same class/name to unsubscribe.

• off - alias for removeListener

• once(String event, [(Class|String) cls], handler)

  Subscribe to first event of that type and source class, if filtered.

• removeAllListeners([String event], [(Class|String) cls])

  Unsubscribe all listeners for that event and source class.