Lifecycle.js provides conventions and helpers to manage the life cycles of Javascript instances.

Lifecycle.js provides conventions and helpers to manage the life cycles of Javascript instances.

#Download Latest (1.1.2):

Please see the release notes for upgrade pointers.

###Module Loading

Lifecycle.js is compatible with RequireJS, CommonJS, Brunch and AMD module loading. Module names:

  • 'lifecycle' - lifecycle.js.

If you need to write code that manages the lifecycle of some javascript objects, but you don't know ahead of time what type of lifecycle model they implement, Lifecycle.js is for you!

A good example of this is Backbone.Articulation. Backbone.Articulation will reconstruct instances of Dates or custom classes within you Backbone.Model's attributes irregardless of what lifecycle model they use (as long as they use one of the known conventions!)

LC.own and LC.disown

Manages the lifecycle of individual instances, objects, arrays, and object properties that comply with some lifecycle conventions:

  • clone() and destroy()
  • retain() and release()
  • clone() and Javascript memory management
  • plain old JSON

Run time determination of the correct lifecycle for an instance:

instance = new MyClass()
owned_copy_instance = LC.own(instance)       # you don't need to know whether MyClass needs to get cloned, retained, etc 
LC.disown(owned_copy_instance)               # you don't need to know whether MyClass needs to get destroyed, released, etc 

It also works for Javascript collection types:

# works for arrays containing instances or primitive types 
an_array = [new Object()‘hello’new Object()]
owned_copy_array = LC.own(an_array)
# works for objects whose properties contain instances or primitive types 
an_object = {one: new Object()two: new Object()three: ‘there’}
owned_copy_object = LC.own(an_object{properties:true})

Very basic implementation following the Coffeescript class pattern for a reference countable class.

CoffeeScript classes:

class MyClass extends LC.RefCountable
  constructor: ->
    @is_alive = true
  __destroy: ->
    @is_alive = false
instance = new MyClass()  # ref_count = 1 
instance.retain()         # ref_count = 2 
instance.release()        # ref_count = 1 
instance.release()        # ref_count = 0 and __destroy() called 

JavaScript classes using extend:

var MyClass = LC.RefCountable.extend({
  constructorfunction() {
    LC.RefCountable.prototype.constructor.apply(this, arguments);
    this.is_alive = true;
  __destroyfunction() {
    this.is_alive = false;
var instance = new MyClass();   // ref_count = 1 
instance.retain();              // ref_count = 2 
instance.release();             // ref_count = 1 
instance.release();             // ref_count = 0 and __destroy() called 


  1. install node.js:
  2. install node packages: 'npm install'


Look at: