var Template = Class.create({ //初始化方法 initialize: function(template, pattern) { this.template = template.toString(); this.pattern = pattern || Template.Pattern; }, //格式化方法，如果从java的角度来说，其实叫format更好 :) evaluate: function(object) {     //检查是否定义了toTemplateReplacements方法，是的话调用     //整个的Prototype框架中，只有Hash对象定义了这个方法 if (object && Object.isFunction(object.toTemplateReplacements)) object = object.toTemplateReplacements();     //这里的gsub是String对象里面的方法，可以简单的认为就是替换字符串中所有匹配pattern的部分 return this.template.gsub(this.pattern, function(match) { //match[0]是整个的匹配Template.Pattern的字符串      //match[1]是匹配字符串前面的一个字符      //match[2]是匹配${var}这个表达式的部分      //match[3]是'#{var}'表达式的'var'部分      //如果object为null，则把所有的${var}表达式替换成'' if (object == null) return (match[1] + '');      //取得匹配表达式前一个字符 var before = match[1] || '';      //如果前一个字符串为'\'，则直接返回匹配的表达式，不进行替换 if (before == '\\') return match[2]; var ctx = object, expr = match[3];      //这个正则表达式好像就是检查var是否是合法的名称，暂时没看懂这个正则表达式的意义？ var pattern = /^([^.[]+|\[((?:.*?[^\\])?)\])(\.|\[|$)/; match = pattern.exec(expr);      //如果var不符合要求，则直接返回前一个字符 if (match == null) return before; //逐个替换'#{var}'表达式部分 while (match != null) {          //不懂下面这个检查什么意思? var comp = match[1].startsWith('[') ? match[2].gsub('\\\\]', ']') : match[1]; ctx = ctx[comp]; if (null == ctx || '' == match[3]) break; expr = expr.substring('[' == match[3] ? match[1].length : match[0].length); match = pattern.exec(expr); }      //返回替换后的结果，'#{var}' ==> 'value' return before + String.interpret(ctx); }); } }); //默认的模板匹配正则表达式，形如#{var},很像JSP中的EL表达式 Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;

var myTemplate = new Template('The TV show #{title} was created by #{author}.'); var show = {title: 'The Simpsons', author: 'Matt Groening', network: 'FOX' }; myTemplate.evaluate(show); // -> The TV show The Simpsons was created by Matt Groening.

var t = new Template('in #{lang} we also use the \\#{variable} syntax for templates.'); var data = {lang:'Ruby', variable: '(not used)'}; t.evaluate(data); // -> in Ruby we also use the #{variable} syntax for templates.

//自定义匹配模式 var syntax = /(^|.|\r|\n)(\<%=\s*(\w+)\s*%\>)/; //matches symbols like '<%= field %>' var t = new Template('<div>Name: <b><%= name %></b>, Age: <b><%=age%></b></div>', syntax); t.evaluate( {name: 'John Smith', age: 26} ); // -> <div>Name: <b>John Smith</b>, Age: <b>26</b></div>

var conversion1 = {from: 'meters', to: 'feet', factor: 3.28}; var conversion2 = {from: 'kilojoules', to: 'BTUs', factor: 0.9478}; var conversion3 = {from: 'megabytes', to: 'gigabytes', factor: 1024}; var templ = new Template('Multiply by #{factor} to convert from #{from} to #{to}.'); [conversion1, conversion2, conversion3].each( function(conv){ templ.evaluate(conv); }); // -> Multiply by 3.28 to convert from meters to feet. // -> Multiply by 0.9478 to convert from kilojoules to BTUs. // -> Multiply by 1024 to convert from megabytes to gigabytes.