Auto Expanding/Grow textarea directive for AngularJS

gistfile1.js

/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2013 Thom Seddon
 * Copyright (c) 2010 Google
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.

 * Adapted from: http://code.google.com/p/gaequery/source/browse/trunk/src/static/scripts/jquery.autogrow-textarea.js
 *
 * Works nicely with the following styles:
 * textarea {
 *  resize: none;
 *  word-wrap: break-word;
 *  transition: 0.05s;
 *  -moz-transition: 0.05s;
 *  -webkit-transition: 0.05s;
 *  -o-transition: 0.05s;
 * }
 *
 * Usage: <textarea auto-grow></textarea>
 */

app.directive('autoGrow', function($window, $timeout) {
  return {
    restrict: 'A',
    link: function (scope, element, attr) {
      element.on('input propertychange', update);

      function update() {
        var scrollTop = $window.pageYOffset,
            scrollLeft = $window.pageXOffset;

        element.css({
          height: 'auto',
          overflow: 'hidden'
        });
        var height = element[0].scrollHeight;

        if (height > 0) {
          element.css('height', height + 'px');
        }

        $window.scrollTo(scrollLeft, scrollTop);
      }
        
      $timeout(update); // update on page load
    }
  };
});