Sending postMessage events

send-postMessage-events.js

function throttle(fn, threshhold = 250, scope) {
  var last,
      deferTimer;
  return function () {
    var context = scope || this;

    var now = +new Date,
        args = arguments;
    if (last && now < last + threshhold) {
      // hold on to it
      clearTimeout(deferTimer);
      deferTimer = setTimeout(function () {
        last = now;
        fn.apply(context, args);
      }, threshhold);
    } else {
      last = now;
      fn.apply(context, args);
    }
  };
}
function sendHeight(){
    var $container = document.querySelector('body > .container');
    if($container && $container.offsetHeight){
      parent.postMessage($container.offsetHeight, "*");
    }
}
if(parent.postMessage){
  addEventListener('resize', throttle(sendHeight, 100));
  addEventListener("DOMContentLoaded", sendHeight);
}