    /**
     * @class Ext.dom.Helper
     * @extends Ext.dom.AbstractHelper
     * @alternateClassName Ext.DomHelper
     * @alternateClassName Ext.core.DomHelper
     * @singleton
     *
     * The DomHelper class provides a layer of abstraction from DOM and transparently supports creating elements via DOM or
     * using HTML fragments. It also has the ability to create HTML fragment templates from your DOM building code.
     *
     * # DomHelper element specification object
     *
     * A specification object is used when creating elements. Attributes of this object are assumed to be element
     * attributes, except for 4 special attributes:
     *
     * - **tag** - The tag name of the element.
     * - **children** or **cn** - An array of the same kind of element definition objects to be created and appended.
     *   These can be nested as deep as you want.
     * - **cls** - The class attribute of the element. This will end up being either the "class" attribute on a HTML
     *   fragment or className for a DOM node, depending on whether DomHelper is using fragments or DOM.
     * - **html** - The innerHTML for the element.
     *
     * **NOTE:** For other arbitrary attributes, the value will currently **not** be automatically HTML-escaped prior to
     * building the element's HTML string. This means that if your attribute value contains special characters that would
     * not normally be allowed in a double-quoted attribute value, you **must** manually HTML-encode it beforehand (see
     * {@link Ext.String#htmlEncode}) or risk malformed HTML being created. This behavior may change in a future release.
     *
     * # Insertion methods
     *
     * Commonly used insertion methods:
     *
     * - **{@link #append}**
     * - **{@link #insertBefore}**
     * - **{@link #insertAfter}**
     * - **{@link #overwrite}**
     * - **{@link #createTemplate}**
     * - **{@link #insertHtml}**
     *
     * # Example
     *
     * This is an example, where an unordered list with 3 children items is appended to an existing element with
     * id 'my-div':
     *
     *     var dh = Ext.DomHelper; // create shorthand alias
     *     // specification object
     *     var spec = {
     *         id: 'my-ul',
     *         tag: 'ul',
     *         cls: 'my-list',
     *         // append children after creating
     *         children: [     // may also specify 'cn' instead of 'children'
     *             {tag: 'li', id: 'item0', html: 'List Item 0'},
     *             {tag: 'li', id: 'item1', html: 'List Item 1'},
     *             {tag: 'li', id: 'item2', html: 'List Item 2'}
     *         ]
     *     };
     *     var list = dh.append(
     *         'my-div', // the context element 'my-div' can either be the id or the actual node
     *         spec      // the specification object
     *     );
     *
     * Element creation specification parameters in this class may also be passed as an Array of specification objects. This
     * can be used to insert multiple sibling nodes into an existing container very efficiently. For example, to add more
     * list items to the example above:
     *
     *     dh.append('my-ul', [
     *         {tag: 'li', id: 'item3', html: 'List Item 3'},
     *         {tag: 'li', id: 'item4', html: 'List Item 4'}
     *     ]);
     *
     * # Templating
     *
     * The real power is in the built-in templating. Instead of creating or appending any elements, {@link #createTemplate}
     * returns a Template object which can be used over and over to insert new elements. Revisiting the example above, we
     * could utilize templating this time:
     *
     *     // create the node
     *     var list = dh.append('my-div', {tag: 'ul', cls: 'my-list'});
     *     // get template
     *     var tpl = dh.createTemplate({tag: 'li', id: 'item{0}', html: 'List Item {0}'});
     *
     *     for(var i = 0; i < 5, i++){
     *         tpl.append(list, [i]); // use template to append to the actual node
     *     }
     *
     * An example using a template:
     *
     *     var html = '<a id="{0}" href="{1}" class="nav">{2}</a>';
     *
     *     var tpl = new Ext.DomHelper.createTemplate(html);
     *     tpl.append('blog-roll', ['link1', 'http://www.edspencer.net/', "Ed's Site"]);
     *     tpl.append('blog-roll', ['link2', 'http://www.dustindiaz.com/', "Dustin's Site"]);
     *
     * The same example using named parameters:
     *
     *     var html = '<a id="{id}" href="{url}" class="nav">{text}</a>';
     *
     *     var tpl = new Ext.DomHelper.createTemplate(html);
     *     tpl.append('blog-roll', {
     *         id: 'link1',
     *         url: 'http://www.edspencer.net/',
     *         text: "Ed's Site"
     *     });
     *     tpl.append('blog-roll', {
     *         id: 'link2',
     *         url: 'http://www.dustindiaz.com/',
     *         text: "Dustin's Site"
     *     });
     *
     * # Compiling Templates
     *
     * Templates are applied using regular expressions. The performance is great, but if you are adding a bunch of DOM
     * elements using the same template, you can increase performance even further by {@link Ext.Template#compile
     * "compiling"} the template. The way "{@link Ext.Template#compile compile()}" works is the template is parsed and
     * broken up at the different variable points and a dynamic function is created and eval'ed. The generated function
     * performs string concatenation of these parts and the passed variables instead of using regular expressions.
     *
     *     var html = '<a id="{id}" href="{url}" class="nav">{text}</a>';
     *
     *     var tpl = new Ext.DomHelper.createTemplate(html);
     *     tpl.compile();
     *
     *     //... use template like normal
     *
     * # Performance Boost
     *
     * DomHelper will transparently create HTML fragments when it can. Using HTML fragments instead of DOM can significantly
     * boost performance.
     *
     * Element creation specification parameters may also be strings. If {@link #useDom} is false, then the string is used
     * as innerHTML. If {@link #useDom} is true, a string specification results in the creation of a text node. Usage:
     *
     *     Ext.DomHelper.useDom = true; // force it to use DOM; reduces performance
     *
     */
    (function() {

    // kill repeat to save bytes
    var afterbegin = 'afterbegin',
        afterend = 'afterend',
        beforebegin = 'beforebegin',
        beforeend = 'beforeend',
        ts = '<table>',
        te = '</table>',
        tbs = ts+'<tbody>',
        tbe = '</tbody>'+te,
        trs = tbs + '<tr>',
        tre = '</tr>'+tbe,
        detachedDiv = document.createElement('div'),
        bbValues = ['BeforeBegin', 'previousSibling'],
        aeValues = ['AfterEnd', 'nextSibling'],
        bb_ae_PositionHash = {
            beforebegin: bbValues,
            afterend: aeValues
        },
        fullPositionHash = {
            beforebegin: bbValues,
            afterend: aeValues,
            afterbegin: ['AfterBegin', 'firstChild'],
            beforeend: ['BeforeEnd', 'lastChild']
        };

    Ext.define('Ext.dom.Helper', {
        extend: 'Ext.dom.AbstractHelper',

        tableRe: /^table|tbody|tr|td$/i,

        tableElRe: /td|tr|tbody/i,

        /**
         * @property {Boolean} useDom
         * True to force the use of DOM instead of html fragments.
         */
        useDom : false,

        /**
         * Creates new DOM element(s) without inserting them to the document.
         * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
         * @return {HTMLElement} The new uninserted node
         */
        createDom: function(o, parentNode){
            var el,
                doc = document,
                useSet,
                attr,
                val,
                cn,
                i, l;

            if (Ext.isArray(o)) {                       // Allow Arrays of siblings to be inserted
                el = doc.createDocumentFragment(); // in one shot using a DocumentFragment
                for (i = 0, l = o.length; i < l; i++) {
                    this.createDom(o[i], el);
                }
            } else if (typeof o == 'string') {         // Allow a string as a child spec.
                el = doc.createTextNode(o);
            } else {
                el = doc.createElement(o.tag || 'div');
                useSet = !!el.setAttribute; // In IE some elements don't have setAttribute
                for (attr in o) {
                    if (!this.confRe.test(attr)) {
                        val = o[attr];
                        if (attr == 'cls') {
                            el.className = val;
                        } else {
                            if (useSet) {
                                el.setAttribute(attr, val);
                            } else {
                                el[attr] = val;
                            }
                        }
                    }
                }
                Ext.DomHelper.applyStyles(el, o.style);

                if ((cn = o.children || o.cn)) {
                    this.createDom(cn, el);
                } else if (o.html) {
                    el.innerHTML = o.html;
                }
            }
            if (parentNode) {
                parentNode.appendChild(el);
            }
            return el;
        },

        ieTable: function(depth, openingTags, htmlContent, closingTags){
            detachedDiv.innerHTML = [openingTags, htmlContent, closingTags].join('');

            var i = -1,
                el = detachedDiv,
                ns;

            while (++i < depth) {
                el = el.firstChild;
            }
            // If the result is multiple siblings, then encapsulate them into one fragment.
            ns = el.nextSibling;

            if (ns) {
                el = document.createDocumentFragment();
                while (ns) {
                    el.appendChild(ns);
                    ns = ns.nextSibling;
                }
            }
            return el;
        },

        /**
         * @private
         * Nasty code for IE's broken table implementation
         */
        insertIntoTable: function(tag, where, destinationEl, html) {
            var node,
                before,
                bb = where == beforebegin,
                ab = where == afterbegin,
                be = where == beforeend,
                ae = where == afterend;

            if (tag == 'td' && (ab || be) || !this.tableElRe.test(tag) && (bb || ae)) {
                return null;
            }
            before = bb ? destinationEl :
                     ae ? destinationEl.nextSibling :
                     ab ? destinationEl.firstChild : null;

            if (bb || ae) {
                destinationEl = destinationEl.parentNode;
            }

            if (tag == 'td' || (tag == 'tr' && (be || ab))) {
                node = this.ieTable(4, trs, html, tre);
            } else if ((tag == 'tbody' && (be || ab)) ||
                    (tag == 'tr' && (bb || ae))) {
                node = this.ieTable(3, tbs, html, tbe);
            } else {
                node = this.ieTable(2, ts, html, te);
            }
            destinationEl.insertBefore(node, before);
            return node;
        },

        /**
         * @private
         * Fix for IE9 createContextualFragment missing method
         */
        createContextualFragment: function(html) {
            var fragment = document.createDocumentFragment(),
                length, childNodes;

            detachedDiv.innerHTML = html;
            childNodes = detachedDiv.childNodes;
            length = childNodes.length;

            // Move nodes into fragment, don't clone: http://jsperf.com/create-fragment
            while (length--) {
                fragment.appendChild(childNodes[0]);
            }
            return fragment;
        },

        applyStyles: function(el, styles) {
            if (styles) {
                el = Ext.fly(el);
                if (typeof styles == "function") {
                    styles = styles.call();
                }
                if (typeof styles == "string") {
                    styles = Ext.dom.Element.parseStyles(styles);
                }
                if (typeof styles == "object") {
                    el.setStyle(styles);
                }
            }
        },

        /**
         * Alias for {@link #markup}.
         * @inheritdoc Ext.dom.AbstractHelper#markup
         */
        createHtml: function(spec) {
            return this.markup(spec);
        },

        doInsert: function(el, o, returnElement, pos, sibling, append) {

            el = el.dom || Ext.getDom(el);

            var newNode;

            if (this.useDom) {
                newNode = this.createDom(o, null);

                if (append) {
                    el.appendChild(newNode);
                }
                else {
                    (sibling == 'firstChild' ? el : el.parentNode).insertBefore(newNode, el[sibling] || el);
                }

            } else {
                newNode = this.insertHtml(pos, el, this.markup(o));
            }
            return returnElement ? Ext.get(newNode, true) : newNode;
        },

        /**
         * Creates new DOM element(s) and overwrites the contents of el with them.
         * @param {String/HTMLElement/Ext.Element} el The context element
         * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
         * @param {Boolean} [returnElement] true to return an Ext.Element
         * @return {HTMLElement/Ext.Element} The new node
         */
        overwrite: function(el, html, returnElement) {
            var newNode;

            el = Ext.getDom(el);
            html = this.markup(html);

            // IE Inserting HTML into a table/tbody/tr requires extra processing: http://www.ericvasilik.com/2006/07/code-karma.html
            if (Ext.isIE && this.tableRe.test(el.tagName)) {
                // Clearing table elements requires removal of all elements.
                while (el.firstChild) {
                    el.removeChild(el.firstChild);
                }
                if (html) {
                    newNode = this.insertHtml('afterbegin', el, html);
                    return returnElement ? Ext.get(newNode) : newNode;
                }
                return null;
            }
            el.innerHTML = html;
            return returnElement ? Ext.get(el.firstChild) : el.firstChild;
        },

        insertHtml: function(where, el, html) {
            var hashVal,
                range,
                rangeEl,
                setStart,
                frag;

            where = where.toLowerCase();

            // Has fast HTML insertion into existing DOM: http://www.w3.org/TR/html5/apis-in-html-documents.html#insertadjacenthtml
            if (el.insertAdjacentHTML) {

                // IE's incomplete table implementation: http://www.ericvasilik.com/2006/07/code-karma.html
                if (Ext.isIE && this.tableRe.test(el.tagName) && (frag = this.insertIntoTable(el.tagName.toLowerCase(), where, el, html))) {
                    return frag;
                }

                if ((hashVal = fullPositionHash[where])) {
                    el.insertAdjacentHTML(hashVal[0], html);
                    return el[hashVal[1]];
                }
                // if (not IE and context element is an HTMLElement) or TextNode
            } else {
                // we cannot insert anything inside a textnode so...
                if (el.nodeType === 3) {
                    where = where === 'afterbegin' ? 'beforebegin' : where;
                    where = where === 'beforeend' ? 'afterend' : where;
                }
                range = Ext.supports.CreateContextualFragment ? el.ownerDocument.createRange() : undefined;
                setStart = 'setStart' + (this.endRe.test(where) ? 'After' : 'Before');
                if (bb_ae_PositionHash[where]) {
                    if (range) {
                        range[setStart](el);
                        frag = range.createContextualFragment(html);
                    } else {
                        frag = this.createContextualFragment(html);
                    }
                    el.parentNode.insertBefore(frag, where == beforebegin ? el : el.nextSibling);
                    return el[(where == beforebegin ? 'previous' : 'next') + 'Sibling'];
                } else {
                    rangeEl = (where == afterbegin ? 'first' : 'last') + 'Child';
                    if (el.firstChild) {
                        if (range) {
                            range[setStart](el[rangeEl]);
                            frag = range.createContextualFragment(html);
                        } else {
                            frag = this.createContextualFragment(html);
                        }

                        if (where == afterbegin) {
                            el.insertBefore(frag, el.firstChild);
                        } else {
                            el.appendChild(frag);
                        }
                    } else {
                        el.innerHTML = html;
                    }
                    return el[rangeEl];
                }
            }
            //<debug>
            Ext.Error.raise({
                sourceClass: 'Ext.DomHelper',
                sourceMethod: 'insertHtml',
                htmlToInsert: html,
                targetElement: el,
                msg: 'Illegal insertion point reached: "' + where + '"'
            });
            //</debug>
        },

        /**
         * Creates a new Ext.Template from the DOM object spec.
         * @param {Object} o The DOM object spec (and children)
         * @return {Ext.Template} The new template
         */
        createTemplate: function(o) {
            var html = this.markup(o);
            return new Ext.Template(html);
        }

    }, function() {
        Ext.ns('Ext.core');
        Ext.DomHelper = Ext.core.DomHelper = new this;
    });

    }());