event-tree

Hierachical Event Emitters, (rather like in the browser!)

Usage

events should be objects.

If you emit a non object: et.emit('thing', 'a string') It will be wrapped in an object: {message: 'a string', source: emitter...} This is different to node, but is necessary to keep track of source of an event.

simple

Emit event on parent after emitting it one the child.

 
var EventTree = require('event-tree')
 
var parent = new EventTree(parent)
var child = new EventTree()
 
//or: parent.add(child)
 
parent.on('msg', function (event) {
  console.log(event)
})
 
child.emit('msg', {message: 'hello!'})
 

output:

{event: 'msg', message: 'hello!', source: child, veto: function () {...}}

Veto an event.

if a listener calls veto on the event, it will note be emitted on the parent.

var EventTree = require('event-tree')
 
var parent = new EventTree(parent)
var child = new EventTree()
 
//or: parent.add(child)
 
parent.on('msg', function (event) {
  throw new Error('This Must Not Happen')
})
 
child.on('msg', function (event) {
  event.veto()
})
 
child.emit('msg', {message: 'hello!'})

License

MIT