The source code

    /**
     * @class Ext.Template
     * Represents an HTML fragment template. Templates can be precompiled for greater performance.
     * For a list of available format functions, see {@link Ext.util.Format}.

     * Usage:

    var t = new Ext.Template(
        '<div name="{id}">',
            '<span class="{cls}">{name:trim} {value:ellipsis(10)}</span>',
        '</div>'
    );
    t.append('some-element', {id: 'myid', cls: 'myclass', name: 'foo', value: 'bar'});

     * @constructor
     * @param {String/Array} html The HTML fragment or an array of fragments to join("") or multiple arguments to join("")
     */
    Ext.Template = function(html){
        var me = this,
        	a = arguments,
        	buf = [];

        if (Ext.isArray(html)) {
            html = html.join("");
        } else if (a.length > 1) {
    	    Ext.each(a, function(v) {
                if (Ext.isObject(v)) {
                    Ext.apply(me, v);
                } else {
                    buf.push(v);
                }
            });
            html = buf.join('');
        }

        /**@private*/
        me.html = html;
        if (me.compiled) {
            me.compile();
        }
    };
    Ext.Template.prototype = {
        /**
         * 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
         */
        applyTemplate : function(values){
    		var me = this;

            return me.compiled ?
            		me.compiled(values) :
    				me.html.replace(me.re, function(m, name){
    		        	return values[name] !== undefined ? values[name] : "";
    		        });
    	},

        /**
         * Sets the HTML used as the template and optionally compiles it.
         * @param {String} html
         * @param {Boolean} compile (optional) True to compile the template (defaults to undefined)
         * @return {Ext.Template} this
         */
        set : function(html, compile){
    	    var me = this;
            me.html = html;
            me.compiled = null;
            return compile ? me.compile() : me;
        },

        /**
        * The regular expression used to match template variables
        * @type RegExp
        * @property
        */
        re : /\{([\w-]+)\}/g,

        /**
         * Compiles the template into an internal function, eliminating the RegEx overhead.
         * @return {Ext.Template} this
         */
        compile : function(){
            var me = this,
            	sep = Ext.isGecko ? "+" : ",";

            function fn(m, name){
    	        name = "values['" + name + "']";
    	        return "'"+ sep + '(' + name + " == undefined ? '' : " + name + ')' + sep + "'";
            }

            eval("this.compiled = function(values){ return " + (Ext.isGecko ? "'" : "['") +
                 me.html.replace(/\\/g, '\\\\').replace(/(\r\n|\n)/g, '\\n').replace(/'/g, "\\'").replace(this.re, fn) +
                 (Ext.isGecko ?  "';};" : "'].join('');};"));
            return me;
        },

        /**
         * Applies the supplied values to the template and inserts the new node(s) as the first child of el.
         * @param {Mixed} el The context element
         * @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'})
         * @param {Boolean} returnElement (optional) true to return a Ext.Element (defaults to undefined)
         * @return {HTMLElement/Ext.Element} The new node or Element
         */
        insertFirst: function(el, values, returnElement){
            return this.doInsert('afterBegin', el, values, returnElement);
        },

        /**
         * Applies the supplied values to the template and inserts the new node(s) before el.
         * @param {Mixed} el The context element
         * @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'})
         * @param {Boolean} returnElement (optional) true to return a Ext.Element (defaults to undefined)
         * @return {HTMLElement/Ext.Element} The new node or Element
         */
        insertBefore: function(el, values, returnElement){
            return this.doInsert('beforeBegin', el, values, returnElement);
        },

        /**
         * Applies the supplied values to the template and inserts the new node(s) after el.
         * @param {Mixed} el The context element
         * @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'})
         * @param {Boolean} returnElement (optional) true to return a Ext.Element (defaults to undefined)
         * @return {HTMLElement/Ext.Element} The new node or Element
         */
        insertAfter : function(el, values, returnElement){
            return this.doInsert('afterEnd', el, values, returnElement);
        },

        /**
         * Applies the supplied values to the template and appends the new node(s) to el.
         * @param {Mixed} el The context element
         * @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'})
         * @param {Boolean} returnElement (optional) true to return a Ext.Element (defaults to undefined)
         * @return {HTMLElement/Ext.Element} The new node or Element
         */
        append : function(el, values, returnElement){
            return this.doInsert('beforeEnd', el, values, returnElement);
        },

        doInsert : function(where, el, values, returnEl){
            el = Ext.getDom(el);
            var newNode = Ext.DomHelper.insertHtml(where, el, this.applyTemplate(values));
            return returnEl ? Ext.get(newNode, true) : newNode;
        },

        /**
         * Applies the supplied values to the template and overwrites the content of el with the new node(s).
         * @param {Mixed} el The context element
         * @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'})
         * @param {Boolean} returnElement (optional) true to return a Ext.Element (defaults to undefined)
         * @return {HTMLElement/Ext.Element} The new node or Element
         */
        overwrite : function(el, values, returnElement){
            el = Ext.getDom(el);
            el.innerHTML = this.applyTemplate(values);
            return returnElement ? Ext.get(el.firstChild, true) : el.firstChild;
        }
    };
    /**
     * 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.Template
     * @method apply
     */
    Ext.Template.prototype.apply = Ext.Template.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
     * @param {Object} config A configuration object
     * @return {Ext.Template} The created template
     * @static
     */
    Ext.Template.from = function(el, config){
        el = Ext.getDom(el);
        return new Ext.Template(el.value || el.innerHTML, config || '');
    };