JavaScript closure state manager for a single argument, with support for default state initialization value. A JavaScript private variables method.

helpers.js

;(function(window) {
'use strict';

/**
  filename: helpers.js
  author: gregory tomlinson
  license: MIT

  Be a "utility" helper method
  file that is namespaced to 'helpers'
*/

/**
  Be a "state" handler function

  This closured state handler with built in get/set logic
  can suffice in several scenarios

  this avoids the obtuse 'get/set' syntax in favor
  of a more business-rule friendly, declarative,
  format

   usages:

     INIT: var myFncVar = helpers.closure_state({data:false}); // set default on init
     SET: myFncVar({data:true});
     GET: myFncVar();

  Other examples:

    function Point(cx, cy) {
      this.x = helpers.closure_state(cx);
      this.y = helpers.closure_state(cy);
      return this;
    }

    var pt = new Point(10, 20);
    pt.x();
    // 10
    pt.y();
    // 20

    var myarray = helpers.closure_state([]);
    myarray().push("something")
    myarray()
    // ["something"]
*/


/**
  @params {Array|Object|String|Numnber|ANY} state - a variable of any type. 
                                                    sets default 'state'
*/
function closure_state(state) {
  var STATE = state !== undefined ? state : null;
  return function() {
    if(arguments.length) {
      STATE = arguments[0];
    }
    return STATE;
  }
}

var helpers = window.helpers = {
  closure_state:closure_state
}

})(window);