events-tree

A tree structure for storing and accessing hierarchical event emitters

Install

$ npm install --save events-tree

Usage

var Tree = require('events-tree')
var tree = Tree()
var node = tree.at('foo.bar.baz')

node.on('event', function (value) {
  //=> hello world
})

tree.at('foo.bar.baz').emit('event', 'hello world')

tree.below('foo.bar', function (path, emitter) {
  if (path === 'foo.bar.baz') {
    emitter.emit('event', 'hello world')
  }
})

API

Tree() -> tree

Creates a new event tree.

tree.at(path) -> eventEmitter

Access the EventEmitter at the given path. If no emitter is present, one will be created.

path

Type: string
Default: ''

A property path in dot syntax.

tree.root() -> eventEmitter

Gets/creates the root emitter. Identical to tree.at().

tree.below([path], callback) -> undefined

Traverse downwards through child nodes below the specified path.

path

Type: string
Default: ''

If a callback is passed as the first argument, traversal will begin at the root.

callback

Required
Type: function Arguments: path, emitter

A callback to be called at each child node with the node path (relative to the root) and the emitter. Nodes without an emitter attached will be ignored.

var baz = tree.at('foo.bar.baz')
tree.below('foo', function (path, emitter) {
  // only called once
  // path === 'foo.bar.baz'
  // emitter === baz
})

tree.above(path, callback) -> undefined

Traverse upwards through child nodes above the specified path.

path

Type: string Default: ''

If no path is provided, above is a noop.

callback

Required
Type: function Arguments: path, emitter

A callback to be called at each child node with the node path (relative to the root) and the emitter. Nodes without an emitter attached will be ignored.

License

MIT © Ben Drucker