getHtml.fuse.js

(function($, doc) {
  var getHTML;

  if ('outerHTML' in doc.documentElement) {
    getHTML = function getHTML() {
      return $.String(this.raw.outerHTML);
    };
  } else {
    var dummy = doc.createElement('html');
    getHTML = function getHTML() {
      dummy.appendChild(this.raw.cloneNode(true));
      var result = dummy.innerHTML;
      dummy.innerHTML = '';
      return $.String(result);
    };
  }

  $.dom.Element.plugin.getHTML = getHTML;
})(fuse, document);

getHtml.proto.js

(function(doc) {
  var getHTML;

  if ('outerHTML' in doc.documentElement) {
    getHTML = function getHTML(element) {
      return $(element).outerHTML;
    };
  } else {
    var dummy = doc.createElement('html');
    getHTML = function getHTML(element) {
      dummy.appendChild($(element).cloneNode(true));
      var result = dummy.innerHTML;
      dummy.innerHTML = '';
      return result;
    };
  }

  Element.addMethods({ 'getHTML': getHTML });
})(document);