Question

I have a massive function that I would like to decompose into multiple files. Here is the structure of my function:

var myFunction = function (argument) {
   var private1, private2, private3;

   var gadget1 = (function () {
       // Play around with private1, private2, private3, argument

       return gadget1API;
   }());

   var gadget2 = (function () {
       // Play around with private1, private2, private3, argument

       return gadget2API;
   }());

   var gadget3 = (function () {
       // Play around with private1, private2, private3, argument

       return gadget3API;
   }());

   return myFunctionAPI;
}

Here namespacing the gadgets to spread them over multiple files doesn’t work because they all depend upon private1, private2, private3 which are within the myFunction closure. For this to work, I would need the myFunction closure to close over 3 different files.

Answer 1

You should create it as an object, not a closure, and load it first, something like this:

function myObject(argument) {
   this.arg = argument;
   this.private1 = whatever;
   this.private2 = whatever;
   this.private3 = whatever;

   this.gadget1 = (function () {
   // Play around with this.private1, this.private2, this.private3, this.arg

       return gadget1API;
   }());

   this.gadget2 = (function () {
   // Play around with this.private1, this.private2, this.private3, this.arg

       return gadget2API;
   }());

   this.gadget3 = (function () {
   // Play around with this.private1, this.private2, this.private3, this.arg

       // return gadget3API; i don't see what this is for, so commented out
   }());

   return myFunctionAPI;
}

And instantiate it right after you defined it

var myFunction = new myObject(theargument);

you can access it’s functions like this:

var something1 = myFunction.gadget3();