tabTalk

tabTalk.js

(function(root, mod) {
  if (typeof exports == "object" && typeof module == "object") return mod(exports); // CommonJS
  if (typeof define == "function" && define.amd) return define(["exports"], mod); // AMD
  mod(root.tabTalk || (root.tabTalk = {})); // Plain browser env
})(this, function(exports) {"use strict";
  var 
      win = window
    , storage = win.localStorage
    , prefix = 'tab_'
    , instance = prefix + date.now() // identify this tab
    , matcher = new RegExp(prefix + '\\d{13}$')
    , callbacks = []
  ;

  exports.talk = talk;
  exports.listen = listen;           
                                   
  win.addEventListener('storage', onStorageHandler);
                            
  function onStorageHandler (event) {
    // event.key String the named key that changed
    // event.oldValue and event.newValue are available
    // event.url the page that caused the value to change
    var key = event.key;
    // event's coming from tabTalk and it's not the current tab
    if (key !== instance && matcher.test(key)) {
      if (callbacks.length) {
        callbacks.forEach(function (fn) {
          fn({ key: key, message: event.newValue });
        });
    }
  }
                            
  function talk (message) {
    localStorage[instance] = message;
  }
                            
  function listen (fn) {
    callbacks.push(fn);
  }
});