Convert global function into static utility in javascript

Question

I have a Shape class, it's defined in the global scope:

function Shape(t) {
   this.type;                            
   Shape.prototype.init = function(){
      this.type = t;
      //more work here             
   }
   this.init();                                         
}

I want to consolidate all global functions/classes into a single class to avoid conflicts with global namespace

function Util(){}
Util.Shape = function(){...}
Util.Point = function(){...}

That works, but I don't like repeating Util. each time, so I use a property like a namespace for related functions, in this case, math:

Util.math = {
   Shape: function(t) {
      this.type;                            
      Shape.prototype.init = function(){
         this.type = t; 
         //more work here            
      }
      this.init();                                         
   },
   Point: function(t) {...}
}

But that doesn't work; complains about this.init(); makes sense since Shape.prototype is not needed here, so it's removed:

Util.math = {
   Shape: function(t) {
      this.type;                            
      this.init = function(){
         this.type = t;             
      }
      this.init();                                         
   }
}

Works now:

var square = new Util.math.Shape('square');
var circle = new Util.math.Shape('circle');         
console.log(square.type);  // 'square'
console.log(circle.type);  // 'circle'

Questions:
Any issue with this approach? More effective/cleaner way to do it?

Also, why does this not work? (this is coolness)

Util.math = {
   Shape: function(t) {
      this.type;                            
      this.init = function(){
         this.type = t;             
      }                                         
   }.init(); //<------coolness
}

But that doesn't work; complains about this.init() because a function expression is different to a function declaration. makes sense since Shape.prototype is not needed here—if it's "not needed here" then it was not needed before. — RobG
– RobG, Commented Mar 7, 2014 at 6:29

RobG · Accepted Answer · 2014-03-07 06:41:31Z

0

You can also do:

var myLib = (function() {

  var obj = {};

  function Shape(t) {
    this.init(t);
  }

  Shape.prototype.init = function(t){
     this.type = t;
  }

  obj.Shape = Shape;

  // more stuff

  return obj;
}());

var shape = new myLib.Shape('circle');

console.log(shape.type); // circle

Assuming that the init thing is just an example.

answered Mar 7, 2014 at 6:41

RobG

148k32 gold badges180 silver badges216 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

raffian Over a year ago

Interesting, so obj is like a type store?

RobG Over a year ago

Yes, have a look at how the real MyLibrary is put together.

Collectives™ on Stack Overflow

Convert global function into static utility in javascript

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related