property.js

property.js is a JavaScript Library that Provides Simpler Usage of the Native Properties (as specified in ECMAScript 5, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty for browser support).

The main features are:

• Create properties in a simple way
• Observe changes to the properties
• Use privacy for separation of concern

Creation

var obj = {}; property.mixin(obj); obj.addProperty("phrase", "hello, my name is"); obj.addProperty("name", "Roberto"); obj.addProperty("greeting"). getter(function(){ return obj.phrase + " " + obj.name; }). setter(false);

console.log(obj.greeting); //console: hello, my name is Roberto

obj.name = "Alejandro";

console.log(obj.greeting); //console: hello, my name is Alejandro

Observe

var obj = {}; property.mixin(obj); obj.addProperty("phrase", "hello, my name is"); obj.addProperty("name", "Roberto").observe(function(newVal, oldVal){ console.log("Did you just change name from " + oldVal + " to " + newVal + "?") });

obj.name = "Alejandro"; //console: Did you just change name from Roberto to Alejandro?

Privacy

var obj = {}; property.mixin(obj); obj.addProperty("phrase", "hello, my name is"); var namePrivateScope = obj.addProperty("name", "Roberto").setter(true, true); //second argument specifies if setter is private var greetingFullyPrivate = obj.addProperty(). getter(function(){ return obj.phrase + " " + obj.name; }, true). setter(false);

namePrivateScope("Alejandro"); //Use the private handle to set! console.log(greetingFullyPrivate()); //Use the private handle to get!

console.log(obj.greeting); //Undefined because property is fully private (ie. property isn't present) obj.name = "Alejandro"; //error: Attempt to change private setter publicly