Listen to storage events and re-fire if item changed used lscache

[iabw]

I was trying to hook onto some storage events, and I realized lscache doesn't have helpers for this. Something like

if (window.addEventListener) {
  // Normal browsers
  window.addEventListener("storage", handler, false);
} else {
  // for IE
  window.attachEvent("onstorage", handler);
};

function handler(e) {
  var index = e.key.indexOf('lscache-');
  if (index === 0){
    lscache.trigger(e.key.substr(8), e);
  }
}

would let us do something like

lscache.on('myKey',callback);

This seems cool, right?

You'd also have to add the on/trigger functionality, something like this minimal example.

    on: function(event, callback, context) {
      this.hasOwnProperty('events') || (this.events = {});
      this.events.hasOwnProperty(event) || (this.events[event] = []);
      this.events[event].push([callback, context]);
    },
    trigger: function(event) {
      var tail = Array.prototype.slice.call(arguments, 1),
          callbacks = this.events[event];
      for(var i = 0, l = callbacks.length; i < l; i++) {
        var callback = callbacks[i][0],
            context = callbacks[i][1] === undefined ? this : callbacks[i][1];
        callback.apply(context, tail);
      }
    }

If performing the handler on every storage event isn't preferable, this functionality could hide behind an initialization flag or a helper like lscache.startFiringEvents().