javaScript高级程序设计之动态脚本及动态样式

1、动态加载脚本（src 原理，异步，支持跨域）

var loadScript = function (url, callback) {    var script = document.createElement("script");    script.src = url;    document.getElementsByTagName("head")[0].appendChild(script);    if (script.addEventListener) {        // for w3c        script.onload = function () {            script.onload = null;            script.parentNode.removeChild(script);            callback && callback();        };    } else if (script.readyState) {            // for ie        script.onreadystatechange = function () {            if (script.readyState === "loaded" || script.readyState === "complete") {                script.onreadystatechange = null;                script.parentNode.removeChild(script);                callback && callback();            }        };    } else {        // for lower brower        script.parentNode.removeChild(script);        callback && callback();    }};

2、动态加载样式

var loadStyle = function (CSSText) {    var style = document.createElement("style");    style.type = "text/css";    style.rel = "styleSheet";    try {        style.appendChild(document.createTextNode(cssText));    } catch (ex) {        // for ie        style.styleSheet.cssText = cssText;    }    document.getElementsByTagName("head")[0].appendChild(style);};loadStyle("body{background-color:#aaa;}");