stikjs/stik-dom

(function(self, HTMLElement){
  if (self.document && !("insertAdjacentHTML" in document.createElementNS("http://www.w3.org/1999/xhtml", "_"))) {
    HTMLElement.prototype.insertAdjacentHTML = function(position, html) {
        "use strict";

        var ref = this,
              container = ref.ownerDocument.createElementNS("http://www.w3.org/1999/xhtml", "_"),
              ref_parent = ref.parentNode,
              node, first_child, next_sibling;

        container.innerHTML = html;

        switch (position.toLowerCase()) {
            case "beforebegin":
                while ((node = container.firstChild)) {
                    ref_parent.insertBefore(node, ref);
                }
                break;
            case "afterbegin":
                first_child = ref.firstChild;
                while ((node = container.lastChild)) {
                    first_child = ref.insertBefore(node, first_child);
                }
                break;
            case "beforeend":
                while ((node = container.firstChild)) {
                    ref.appendChild(node);
                }
                break;
            case "afterend":
                next_sibling = ref.nextSibling;
                while ((node = container.lastChild)) {
                    next_sibling = ref_parent.insertBefore(node, next_sibling);
                }
                break;
        }
    };
  }
})(window, window.HTMLElement);