编写可维护的JavaScript之简易模版

/*
 * 正则替换%s
 * @para arg1(text) 需要替换的模版
 * @para arg2 替换第一处%s
 * @para arg3 替换第二处%s
 * 返回替换后的字符串
 */
var sprintf = function (text) {
    var i = 1,
        args = arguments,
        len = args.length;

    return text.replace(/%s/g, function () {
        return (i < len) ? args[i++] : "";
    });
};

/**
    // 文档
    <ul id="my-list">
        <li><a href="#">hello world</a></li>
    </ul>

    // 模版  type="text/template" 服务器不会解析的mime类型
    <script type="text/template" id="list-item">
        <li><a href="%s">%s</a></li>
    </script>
**/


// 添加一个模版节点
var addItem = function (url, text) {
    var _script = document.getElementById("list-item"),
        template = _script.text,
        result = sprintf(template, url, text),
        ele = document.getElementById("my-list"),
        div = document.createElement("div");
    
    // 正则替换后div.firstChild就是Node节点
    div.innerHTML = result.replace(/^s*/, "");  

    ele.appendChild(div.firstChild);        
};

addItem("www.google.com/", "google");

---

一种更好的方式

(function(){
    
    var regexp = /(?:{{)([a-zA-z][^s}]+)(?:}})/g;
    
     function render(template, data) {
        
        return template.replace(regexp, function(fullMatch, capture) {
            if(data[capture]) {
                return data[capture];
            } else {
                return fullMatch;
            }
        });
    }
    
    window.renderTemplate = render;
    
})();


var template = '{{birdname}}---{{birdname}} and name is {{author}}';

var tpl_end = renderTemplate(template, {
    "birdname": "silk",
    "author": "David"
});

console.log(tpl_end); // silk---silk and name is David