CODEWITHSUNDEEP
javascriptclosuresprototype
SReject
SReject

Reputation: 3936

Add reference of caller to in-closure constructor

Ok, I'm creating a constructor object within a closure(to hide it from other scripts that may conflict with it) for another function(this will become clear in a moment). Is there a way to add a reference of the caller function to the in-closed constructor:

// this can be located anywhere within a script
(function() {
    function SomeConstructor(param) { this.param = param; }
    SomeConstructor.prototype.doSomething = function(a) { this.param = a; return this; }
    SomeConstructor.prototype.getParam = function() { return this.param }
    // SomeConstructor.prototype.someFunct = ???

    return function someFunct(param) {
        if (param instanceof SomeConstructor) {
            return param;
        }
        else if (param) {
            return new SomeConstructor(param);
        }
    }
}());

the reason I need the reference is so I can chain between someFunct and it's constructed objects:

someFunct("A").doSomething("a").someFunct("B").doSomething("a").getParam();



Please note I need to retain the instanceof check, so the following functions as specified:

// 1: The inner call creates a new instance of SomeConstructor
// 2: The 2nd(wrapping) call returns the inner calls instance
//        instead of creating a new isntance
var a = someFunct(someFunct("b"));

Upvotes: 1

Views: 144

Answers (1)

cyon
cyon

Reputation: 9538

Assign the function to the property of the prototype first and then return this property:

(function() {
  function SomeConstructor(param) { this.param = param; }
  SomeConstructor.prototype.doSomething = function(a) { this.param = a; return this; }
  SomeConstructor.prototype.getParam = function() { return this.param }
  SomeConstructor.prototype.someFunct = function someFunct(param) {
     if (param) {
          return new SomeConstructor(param);
     }
   }

   return SomeConstructor.prototype.someFunct; 
 }());

Upvotes: 1

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