JavaScript Interface Class

Working on a simple JavaScript idea with implementing Interfaces. Some thought, I have come with this idea. I haven’t worked with it.

For better readability, I extended the Function class:

   1: //Enforces similar data types and has been overridden

   2: Function.prototype.interface = function () {

   3:     if (arguments.length < 1) {

   4:         throw new Error("Interface constructor called with no arguments.");

   5:     }

   6:     var dv = (document.defaultView) ? document.defaultView : document.parentWindow; //Covers < IE9

   7:  

   8:     for (var i = 0,length = arguments.length; i < length; i++) {

   9:         var v = (dv[arguments[i]])

  10:             ? new dv[arguments[i]]

  11:             : {};

  12:         for (var j in v) {

  13:             if (this.hasOwnProperty(j)) {

  14:                 continue;

  15:             }

  16:  

  17:             //Set to generic function enforcing similar types.

  18:             this.prototype[j] = (function(item) {

  19:                 return function (value, overridden) {

  20:                     if (!(overridden && overridden.OR)) {

  21:                         throw new Error("Must be overridden.")

  22:                     }

  23:                     if (Object.prototype.toString.call(value) !== Object.prototype.toString.call(item)) {

  24:                         throw new Error("Members are different types.")

  25:                     };

  26:                     return value;

  27:  

  28:                 }}(v[j]));

  29:         }

  30:     }

  31:  

  32:     return this;

  33: };

  34: Function.prototype.override = function (value) {

  35:     return this.call(null, value,{OR:true});

  36: };

Create class interface without implementation:

   1: var Class1 = function Class1() {

   2:     this.add = {};

   3:     this.subtract = [];

   4: };

   5:  

   6: var Class2 = function () {

   7:     this.times = function () { };

   8:     this.multiply = 9;

   9: };

Create composite that relies on the two interfaces:

   1: var Class3 = function () {

   2:     this.car = "blue";

   3: }.interface("Class1").interface("Class2");

The Composite could also be written:

   1: var Class3 = function () {

   2:     this.car = "blue";

   3: }.interface("Class1","Class2");

Instantiate Class3:

   1: var c = new Class3();

Must be overridden before used:

   1: c.add = c.add.override({ Kirk: "Time" });

If an attempt to use before overriding – Error is thrown. Below shows calling without first overriding resulting in an Error:

   1: c.add = c.add({ Kirk: "Time" }); //Error is thrown

A certain JavaScript design pattern, which assists organizing code.

This post is for the purpose of my notes only.

“I invented nothing new. I simply assembled the discoveries of other men behind whom were centuries of work. Had I worked fifty or ten or even five years before, I would have failed. So it is with every new thing. Progress happens when all the factors that make for it are ready and then it is inevitable. To teach that a comparatively few men are responsible for the greatest forward steps of mankind is the worst sort of nonsense.”
Henry Ford