A function to memoize and throttle a functions result.

cache.js

var cache = function (callback, initialValue, wait) {
  var cachedArgs = [];
  var cachedResults = [];
  var cachedWait = [];
  initialValue = initialValue || function () {
    return undefined;
  };
 
  return function () {
    var args = [].slice.call(arguments, 0);
    var jsonArgs = JSON.stringify(args);
    var cacheIndex = cachedArgs.indexOf(jsonArgs);
    
    if (cacheIndex === -1) {
      cacheIndex = cachedArgs.length;
      cachedArgs.push(jsonArgs);
      cachedResults[cacheIndex] = initialValue();
      cachedWait[cacheIndex] = false
    }
 
    if (cachedWait[cacheIndex] === false) {
      setTimeout(function () {
        cachedResults[cacheIndex] = callback.apply(null, [cachedResults[cacheIndex]].concat(args));
        setTimeout(function () {
          cachedWait[cacheIndex] = false;
        }, wait || 0);
      });
      cachedWait[cacheIndex] = true;
    } else {
      console.info('Not re-running throttled function.');
    }
 
    return cachedResults[cacheIndex];
  };
};

var add = cache(function (cache, x, y) {
  console.log('Trigger an event to refresh app?');
  return x + y;
}, function () {
  return undefined;
}, 2000);

add(10, 11); // Returns undefined until cached function returns.