    /**
     * @class Ext.DomHelper
     * 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 cnAn 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
     *
     *
     * 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 = '{2}';

    var tpl = new Ext.DomHelper.createTemplate(html);
    tpl.append('blog-roll', ['link1', 'http://www.jackslocum.com/', "Jack's Site"]);
    tpl.append('blog-roll', ['link2', 'http://www.dustindiaz.com/', "Dustin's Site"]);
     *
     *
     * The same example using named parameters:
    var html = '{text}';

    var tpl = new Ext.DomHelper.createTemplate(html);
    tpl.append('blog-roll', {
        id: 'link1',
        url: 'http://www.jackslocum.com/',
        text: "Jack'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 = '{text}';

    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
     *
     * @singleton
     */
    Ext.DomHelper = function(){
        var tempTableEl = null,
            emptyTags = /^(?:br|frame|hr|img|input|link|meta|range|spacer|wbr|area|param|col)$/i,
            tableRe = /^table|tbody|tr|td$/i,
            pub,
            // kill repeat to save bytes
            afterbegin = 'afterbegin',
            afterend = 'afterend',
            beforebegin = 'beforebegin',
            beforeend = 'beforeend',
            ts = '',
            te = '',
            tbs = ts+'',
            tbe = ''+te,
            trs = tbs + '',
            tre = ''+tbe;

        // private
        function doInsert(el, o, returnElement, pos, sibling, append){
            var newNode = pub.insertHtml(pos, Ext.getDom(el), createHtml(o));
            return returnElement ? Ext.get(newNode, true) : newNode;
        }

        // build as innerHTML where available
        function createHtml(o){
            var b = '',
                attr,
                val,
                key,
                keyVal,
                cn;

            if(Ext.isString(o)){
                b = o;
            } else if (Ext.isArray(o)) {
                for (var i=0; i < o.length; i++) {
                    if(o[i]) {
                        b += createHtml(o[i]);
                    }
                };
            } else {
                b += '<' + (o.tag = o.tag || 'div');
                Ext.iterate(o, function(attr, val){
                    if(!/tag|children|cn|html$/i.test(attr)){
                        if (Ext.isObject(val)) {
                            b += ' ' + attr + '="';
                            Ext.iterate(val, function(key, keyVal){
                                b += key + ':' + keyVal + ';';
                            });
                            b += '"';
                        }else{
                            b += ' ' + ({cls : 'class', htmlFor : 'for'}[attr] || attr) + '="' + val + '"';
                        }
                    }
                });
                // Now either just close the tag or try to add children and close the tag.
                if (emptyTags.test(o.tag)) {
                    b += '/>';
                } else {
                    b += '>';
                    if ((cn = o.children || o.cn)) {
                        b += createHtml(cn);
                    } else if(o.html){
                        b += o.html;
                    }
                    b += '';
                }
            }
            return b;
        }

        function ieTable(depth, s, h, e){
            tempTableEl.innerHTML = [s, h, e].join('');
            var i = -1,
                el = tempTableEl,
                ns;
            while(++i < depth){
                el = el.firstChild;
            }
    //      If the result is multiple siblings, then encapsulate them into one fragment.
            if(ns = el.nextSibling){
                var df = document.createDocumentFragment();
                while(el){
                    ns = el.nextSibling;
                    df.appendChild(el);
                    el = ns;
                }
                el = df;
            }
            return el;
        }

        /**
         * @ignore
         * Nasty code for IE's broken table implementation
         */
        function insertIntoTable(tag, where, el, html) {
            var node,
                before;

            tempTableEl = tempTableEl || document.createElement('div');

            if(tag == 'td' && (where == afterbegin || where == beforeend) ||
               !/td|tr|tbody/i.test(tag) && (where == beforebegin || where == afterend)) {
                return;
            }
            before = where == beforebegin ? el :
                     where == afterend ? el.nextSibling :
                     where == afterbegin ? el.firstChild : null;

            if (where == beforebegin || where == afterend) {
                el = el.parentNode;
            }

            if (tag == 'td' || (tag == 'tr' && (where == beforeend || where == afterbegin))) {
                node = ieTable(4, trs, html, tre);
            } else if ((tag == 'tbody' && (where == beforeend || where == afterbegin)) ||
                       (tag == 'tr' && (where == beforebegin || where == afterend))) {
                node = ieTable(3, tbs, html, tbe);
            } else {
                node = ieTable(2, ts, html, te);
            }
            el.insertBefore(node, before);
            return node;
        }

        pub = {
            /**
             * Returns the markup for the passed Element(s) config.
             * @param {Object} o The DOM object spec (and children)
             * @return {String}
             */
            markup : function(o){
                return createHtml(o);
            },

            /**
             * Applies a style specification to an element.
             * @param {String/HTMLElement} el The element to apply styles to
             * @param {String/Object/Function} styles A style specification string e.g. 'width:100px', or object in the form {width:'100px'}, or
             * a function which returns such a specification.
             */
            applyStyles : function(el, styles){
                if(styles){
                    var i = 0,
                        len,
                        style;

                    el = Ext.fly(el);
                    if(Ext.isFunction(styles)){
                        styles = styles.call();
                    }
                    if(Ext.isString(styles)){
                        styles = styles.trim().split(/\s*(?::|;)\s*/);
                        for(len = styles.length; i < len;){
                            el.setStyle(styles[i++], styles[i++]);
                        }
                    }else if (Ext.isObject(styles)){
                        el.setStyle(styles);
                    }
                }
            },

            /**
             * Inserts an HTML fragment into the DOM.
             * @param {String} where Where to insert the html in relation to el - beforeBegin, afterBegin, beforeEnd, afterEnd.
             * @param {HTMLElement} el The context element
             * @param {String} html The HTML fragment
             * @return {HTMLElement} The new node
             */
            insertHtml : function(where, el, html){
                var hash = {},
                    hashVal,
                    setStart,
                    range,
                    frag,
                    rangeEl,
                    rs;

                where = where.toLowerCase();
                // add these here because they are used in both branches of the condition.
                hash[beforebegin] = ['BeforeBegin', 'previousSibling'];
                hash[afterend] = ['AfterEnd', 'nextSibling'];

                if (el.insertAdjacentHTML) {
                    if(tableRe.test(el.tagName) && (rs = insertIntoTable(el.tagName.toLowerCase(), where, el, html))){
                        return rs;
                    }
                    // add these two to the hash.
                    hash[afterbegin] = ['AfterBegin', 'firstChild'];
                    hash[beforeend] = ['BeforeEnd', 'lastChild'];
                    if ((hashVal = hash[where])) {
                        el.insertAdjacentHTML(hashVal[0], html);
                        return el[hashVal[1]];
                    }
                } else {
                    range = el.ownerDocument.createRange();
                    setStart = 'setStart' + (/end/i.test(where) ? 'After' : 'Before');
                    if (hash[where]) {
                        range[setStart](el);
                        frag = range.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) {
                            range[setStart](el[rangeEl]);
                            frag = range.createContextualFragment(html);
                            if(where == afterbegin){
                                el.insertBefore(frag, el.firstChild);
                            }else{
                                el.appendChild(frag);
                            }
                        } else {
                            el.innerHTML = html;
                        }
                        return el[rangeEl];
                    }
                }
                throw 'Illegal insertion point -> "' + where + '"';
            },

            /**
             * Creates new DOM element(s) and inserts them before el.
             * @param {Mixed} el The context element
             * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
             * @param {Boolean} returnElement (optional) true to return a Ext.Element
             * @return {HTMLElement/Ext.Element} The new node
             */
            insertBefore : function(el, o, returnElement){
                return doInsert(el, o, returnElement, beforebegin);
            },

            /**
             * Creates new DOM element(s) and inserts them after el.
             * @param {Mixed} el The context element
             * @param {Object} o The DOM object spec (and children)
             * @param {Boolean} returnElement (optional) true to return a Ext.Element
             * @return {HTMLElement/Ext.Element} The new node
             */
            insertAfter : function(el, o, returnElement){
                return doInsert(el, o, returnElement, afterend, 'nextSibling');
            },

            /**
             * Creates new DOM element(s) and inserts them as the first child of el.
             * @param {Mixed} el The context element
             * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
             * @param {Boolean} returnElement (optional) true to return a Ext.Element
             * @return {HTMLElement/Ext.Element} The new node
             */
            insertFirst : function(el, o, returnElement){
                return doInsert(el, o, returnElement, afterbegin, 'firstChild');
            },

            /**
             * Creates new DOM element(s) and appends them to el.
             * @param {Mixed} el The context element
             * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
             * @param {Boolean} returnElement (optional) true to return a Ext.Element
             * @return {HTMLElement/Ext.Element} The new node
             */
            append : function(el, o, returnElement){
                return doInsert(el, o, returnElement, beforeend, '', true);
            },

            /**
             * Creates new DOM element(s) and overwrites the contents of el with them.
             * @param {Mixed} el The context element
             * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
             * @param {Boolean} returnElement (optional) true to return a Ext.Element
             * @return {HTMLElement/Ext.Element} The new node
             */
            overwrite : function(el, o, returnElement){
                el = Ext.getDom(el);
                el.innerHTML = createHtml(o);
                return returnElement ? Ext.get(el.firstChild) : el.firstChild;
            },

            createHtml : createHtml
        };
        return pub;
    }();