Autogrow Textarea with AngularJS

ngAutoGrow.js

// MIT Licence (MIT)
// Copyright (c) 2015 - Mokhamad Rofiudin
// inspired by Facebook Textarea
// Based on code here https://gist.github.com/thomseddon/4703968
// The Magic Sauce : http://stackoverflow.com/a/3238543/4711810

// How to use : <textarea auto-grow></textarea>
// For jQuery visit here : https://gist.github.com/mrofi/a5c6bc25539eacf1750b

app.directive('autoGrow', function() {
  return function(scope, element, attr){
    var textarea = element[0];
    textarea.lineHeight = parseInt(element.css("line-height"), 3);

     var sizeUp = function(textarea) {
        while(textarea.clientHeight < textarea.scrollHeight){
          var height = textarea.clientHeight + textarea.lineHeight;
          $(textarea).css("height", height);
        }
    };
    var sizeDown = function(textarea) {
        do {
          var height = textarea.clientHeight - textarea.lineHeight;
          $(textarea).css("height", height);
        } while(textarea.clientHeight >= textarea.scrollHeight)
          sizeUp(textarea);
    };

    element.data('oldValue', textarea.value);
    sizeDown(textarea);
    element.bind('focus focusin keyup', function() {
        textarea.interval = setInterval(function() {
            if (element.data('oldValue').length < textarea.value.length) {
              sizeUp(textarea);
            } else if (element.data('oldValue').length > textarea.value.length) {
              sizeDown(textarea);
            }
           element.data('oldValue', textarea.value);
        }, 20);
    }).bind('focusout blur', function() {
        clearInterval(textarea.interval);
    });
  }
});