gistfile1.txt

var Obj = require('parsed/object')
var LocalStorage = require('parsed/object/localstorage')
var Validation = require('parsed/object/validation')

var Task = Obj.create('Task', {
  implement: [LocalStorage, Validation]
}, {
  init: function () {
    
  }
})

localstorage.js

var LocalStorage = function () {
  
}

LocalStorage.prototype = {
  listeners: {
    'saved':'save'
  },
  save: function (err, data) {
    if (!err)
    localStorageAllTheThings(data)
  }
}

validate.js

var Validate = function () {

}

Validate.prototype = {
  listeners: {
    'data.set':'validate'
    'init': 'setup'
  },
  setup: function () {
    
  },
  validate: function (key, data) {
    if (this.rules[key]) {
      // somehow validate this junk.
      // otherwise throw an error?
    }
  }
}

Then in init i would do:

init: function(){
    this.setupLocalStorage(options);
    this.setupValidation(options);
},

set: function(key, value){
    // assuming access to parent class object
    // this would validate because we've setup validation.
    // and if we're using emitting events in the "parent" set method,
    // then setupLocationStorage would be written to attach itself to the events
    // emitted by the set method.
    if (this.validate(key, value)) this.parent('set', key, value);
}