The source code

    /**
     * @class Ext.XTemplate
     * @extends Ext.Template
     * A template class that supports advanced functionality like autofilling arrays, conditional processing with
     * basic comparison operators, sub-templates, basic math function support, special built-in template variables,
     * inline code execution and more.  XTemplate also provides the templating mechanism built into {@link Ext.DataView}.
     * XTemplate supports many special tags and built-in operators that aren't defined as part of the API, but are
     * supported in the templates that can be created.  The following examples demonstrate all of the supported features.
     * This is the data object used for reference in each code example:
     *
    var data = {
        name: 'Jack Slocum',
        title: 'Lead Developer',
        company: 'Ext JS, LLC',
        email: 'jack@extjs.com',
        address: '4 Red Bulls Drive',
        city: 'Cleveland',
        state: 'Ohio',
        zip: '44102',
        drinks: ['Red Bull', 'Coffee', 'Water'],
        kids: [{
            name: 'Sara Grace',
            age:3
        },{
            name: 'Zachary',
            age:2
        },{
            name: 'John James',
            age:0
        }]
    };
     *
     * Auto filling of arrays
    The tpl tag and the for operator are used
     * to process the provided data object. If for="." is specified, the data object provided
     * is examined. If the variable in for is an array, it will auto-fill, repeating the template
     * block inside the tpl tag for each item in the array:
     *
    var tpl = new Ext.XTemplate(
        '<p>Kids: ',
        '<tpl for=".">',
            '<p>{name}</p>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data.kids); // pass the kids property of the data object
     *
     * Scope switching
    The for property can be leveraged to access specified members
     * of the provided data object to populate the template:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Title: {title}</p>',
        '<p>Company: {company}</p>',
        '<p>Kids: ',
        '<tpl for="kids">', // interrogate the kids property within the data
            '<p>{name}</p>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data);
     *
     * Access to parent object from within sub-template scope
    When processing a sub-template, for example while
     * looping through a child array, you can access the parent object's members via the parent object:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Kids: ',
        '<tpl for="kids">',
            '<tpl if="age &gt; 1">',  // <-- Note that the > is encoded
                '<p>{name}</p>',
                '<p>Dad: {parent.name}</p>',
            '</tpl>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data);

     * Array item index and basic math support
    While processing an array, the special variable {#}
     * will provide the current array index + 1 (starts at 1, not 0). Templates also support the basic math operators
     * + - * and / that can be applied directly on numeric data values:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Kids: ',
        '<tpl for="kids">',
            '<tpl if="age &gt; 1">',  // <-- Note that the > is encoded
                '<p>{#}: {name}</p>',  // <-- Auto-number each item
                '<p>In 5 Years: {age+5}</p>',  // <-- Basic math
                '<p>Dad: {parent.name}</p>',
            '</tpl>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data);

     * Auto-rendering of flat arrays
    Flat arrays that contain values (and not objects) can be auto-rendered
     * using the special {.} variable inside a loop.  This variable will represent the value of
     * the array at the current index:
     *
    var tpl = new Ext.XTemplate(
        '<p>{name}\'s favorite beverages:</p>',
        '<tpl for="drinks">',
           '<div> - {.}</div>',
        '</tpl>'
    );
    tpl.overwrite(panel.body, data);

     * Basic conditional logic
    Using the tpl tag and the if
     * operator you can provide conditional checks for deciding whether or not to render specific parts of the template.
     * Note that there is no else operator — if needed, you should use two opposite if statements.
     * Properly-encoded attributes are required as seen in the following example:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Kids: ',
        '<tpl for="kids">',
            '<tpl if="age &gt; 1">',  // <-- Note that the > is encoded
                '<p>{name}</p>',
            '</tpl>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data);

     * Ability to execute arbitrary inline code
    In an XTemplate, anything between {[ ... ]}  is considered
     * code to be executed in the scope of the template. There are some special variables available in that code:
     *
     * values: The values in the current scope. If you are using scope changing sub-templates, you
     * can change what values is.
     * parent: The scope (values) of the ancestor template.
     * xindex: If you are in a looping template, the index of the loop you are in (1-based).
     * xcount: If you are in a looping template, the total length of the array you are looping.
     * fm: An alias for Ext.util.Format.
     *
     * This example demonstrates basic row striping using an inline code block and the xindex variable:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Company: {[values.company.toUpperCase() + ", " + values.title]}</p>',
        '<p>Kids: ',
        '<tpl for="kids">',
           '<div class="{[xindex % 2 === 0 ? "even" : "odd"]}">',
            '{name}',
            '</div>',
        '</tpl></p>'
    );
    tpl.overwrite(panel.body, data);

     * Template member functions
    One or more member functions can be defined directly on the config
     * object passed into the XTemplate constructor for more complex processing:
     *
    var tpl = new Ext.XTemplate(
        '<p>Name: {name}</p>',
        '<p>Kids: ',
        '<tpl for="kids">',
            '<tpl if="this.isGirl(name)">',
                '<p>Girl: {name} - {age}</p>',
            '</tpl>',
            '<tpl if="this.isGirl(name) == false">',
                '<p>Boy: {name} - {age}</p>',
            '</tpl>',
            '<tpl if="this.isBaby(age)">',
                '<p>{name} is a baby!</p>',
            '</tpl>',
        '</tpl></p>', {
         isGirl: function(name){
             return name == 'Sara Grace';
         },
         isBaby: function(age){
            return age < 1;
         }
    });
    tpl.overwrite(panel.body, data);

     * @constructor
     * @param {String/Array/Object} parts The HTML fragment or an array of fragments to join(""), or multiple arguments
     * to join("") that can also include a config object
     */
    Ext.XTemplate = function(){
        Ext.XTemplate.superclass.constructor.apply(this, arguments);

        var me = this,
        	s = me.html,
        	re = /]*>((?:(?=([^<]+))\2|<(?!tpl\b[^>]*>))*?)<\/tpl>/,
        	nameRe = /^]*?for="(.*?)"/,
        	ifRe = /^]*?if="(.*?)"/,
        	execRe = /^]*?exec="(.*?)"/,
        	m,
        	id = 0,
        	tpls = [],
        	VALUES = 'values',
        	PARENT = 'parent',
        	XINDEX = 'xindex',
        	XCOUNT = 'xcount',
        	RETURN = 'return ',
        	WITHVALUES = 'with(values){ ';

        s = ['', s, ''].join('');

        while((m = s.match(re))){
           	var m2 = m[0].match(nameRe),
    			m3 = m[0].match(ifRe),
           		m4 = m[0].match(execRe),
           		exp = null,
           		fn = null,
           		exec = null,
           		name = m2 && m2[1] ? m2[1] : '';

           if (m3) {
               exp = m3 && m3[1] ? m3[1] : null;
               if(exp){
                   fn = new Function(VALUES, PARENT, XINDEX, XCOUNT, WITHVALUES + RETURN +(Ext.util.Format.htmlDecode(exp))+'; }');
               }
           }
           if (m4) {
               exp = m4 && m4[1] ? m4[1] : null;
               if(exp){
                   exec = new Function(VALUES, PARENT, XINDEX, XCOUNT, WITHVALUES +(Ext.util.Format.htmlDecode(exp))+'; }');
               }
           }
           if(name){
               switch(name){
                   case '.': name = new Function(VALUES, PARENT, WITHVALUES + RETURN + VALUES + '; }'); break;
                   case '..': name = new Function(VALUES, PARENT, WITHVALUES + RETURN + PARENT + '; }'); break;
                   default: name = new Function(VALUES, PARENT, WITHVALUES + RETURN + name + '; }');
               }
           }
           tpls.push({
                id: id,
                target: name,
                exec: exec,
                test: fn,
                body: m[1]||''
            });
           s = s.replace(m[0], '{xtpl'+ id + '}');
           ++id;
        }
    	Ext.each(tpls, function(t) {
            me.compileTpl(t);
        });
        me.master = tpls[tpls.length-1];
        me.tpls = tpls;
    };
    Ext.extend(Ext.XTemplate, Ext.Template, {
        // private
        re : /\{([\w-\.\#]+)(?:\:([\w\.]*)(?:\((.*?)?\))?)?(\s?[\+\-\*\\]\s?[\d\.\+\-\*\\\(\)]+)?\}/g,
        // private
        codeRe : /\{\[((?:\\\]|.|\n)*?)\]\}/g,

        // private
        applySubTemplate : function(id, values, parent, xindex, xcount){
            var me = this,
            	len,
            	t = me.tpls[id],
            	vs,
            	buf = [];
            if ((t.test && !t.test.call(me, values, parent, xindex, xcount)) ||
                (t.exec && t.exec.call(me, values, parent, xindex, xcount))) {
                return '';
            }
            vs = t.target ? t.target.call(me, values, parent) : values;
            len = vs.length;
            parent = t.target ? values : parent;
            if(t.target && Ext.isArray(vs)){
    	        Ext.each(vs, function(v, i) {
                    buf[buf.length] = t.compiled.call(me, v, parent, i+1, len);
                });
                return buf.join('');
            }
            return t.compiled.call(me, vs, parent, xindex, xcount);
        },

        // private
        compileTpl : function(tpl){
            var fm = Ext.util.Format,
           		useF = this.disableFormats !== true,
                sep = Ext.isGecko ? "+" : ",",
                body;

            function fn(m, name, format, args, math){
                if(name.substr(0, 4) == 'xtpl'){
                    return "'"+ sep +'this.applySubTemplate('+name.substr(4)+', values, parent, xindex, xcount)'+sep+"'";
                }
                var v;
                if(name === '.'){
                    v = 'values';
                }else if(name === '#'){
                    v = 'xindex';
                }else if(name.indexOf('.') != -1){
                    v = name;
                }else{
                    v = "values['" + name + "']";
                }
                if(math){
                    v = '(' + v + math + ')';
                }
                if (format && useF) {
                    args = args ? ',' + args : "";
                    if(format.substr(0, 5) != "this."){
                        format = "fm." + format + '(';
                    }else{
                        format = 'this.call("'+ format.substr(5) + '", ';
                        args = ", values";
                    }
                } else {
                    args= ''; format = "("+v+" === undefined ? '' : ";
                }
                return "'"+ sep + format + v + args + ")"+sep+"'";
            }

            function codeFn(m, code){
                return "'"+ sep +'('+code+')'+sep+"'";
            }

            // branched to use + in gecko and [].join() in others
            if(Ext.isGecko){
                body = "tpl.compiled = function(values, parent, xindex, xcount){ return '" +
                       tpl.body.replace(/(\r\n|\n)/g, '\\n').replace(/'/g, "\\'").replace(this.re, fn).replace(this.codeRe, codeFn) +
                        "';};";
            }else{
                body = ["tpl.compiled = function(values, parent, xindex, xcount){ return ['"];
                body.push(tpl.body.replace(/(\r\n|\n)/g, '\\n').replace(/'/g, "\\'").replace(this.re, fn).replace(this.codeRe, codeFn));
                body.push("'].join('');};");
                body = body.join('');
            }
            eval(body);
            return this;
        },

        /**
         * Returns an HTML fragment of this template with the specified values applied.
         * @param {Object} values The template values. Can be an array if your params are numeric (i.e. {0}) or an object (i.e. {foo: 'bar'})
         * @return {String} The HTML fragment
         */
        applyTemplate : function(values){
            return this.master.compiled.call(this, values, {}, 1, 1);
        },

        /**
         * Compile the template to a function for optimized performance.  Recommended if the template will be used frequently.
         * @return {Function} The compiled function
         */
        compile : function(){return this;}

        /**
         * @property re
         * @hide
         */
        /**
         * @property disableFormats
         * @hide
         */
        /**
         * @method set
         * @hide
         */

    });
    /**
     * Alias for {@link #applyTemplate}
     * Returns an HTML fragment of this template with the specified values applied.
     * @param {Object/Array} values The template values. Can be an array if your params are numeric (i.e. {0}) or an object (i.e. {foo: 'bar'})
     * @return {String} The HTML fragment
     * @member Ext.XTemplate
     * @method apply
     */
    Ext.XTemplate.prototype.apply = Ext.XTemplate.prototype.applyTemplate;

    /**
     * Creates a template from the passed element's value (display:none textarea, preferred) or innerHTML.
     * @param {String/HTMLElement} el A DOM element or its id
     * @return {Ext.Template} The created template
     * @static
     */
    Ext.XTemplate.from = function(el){
        el = Ext.getDom(el);
        return new Ext.XTemplate(el.value || el.innerHTML);
    };