适用于小站点，这很极致，很快速~~
/**
* Created by SevenNight on 2016/9/21 0021.
* 插件功能：使用localStorage缓存js和css文件，减少http请求和页面渲染时间
* 使用方法：
* 1.使用此插件前，需要给插件的pageVersion变量赋值，建议变量值由服务器后端输出，当需要更新客户端资源时，修改版本值即可。
* 2.加载Js：由于js加载有顺序要求，所以需要将后加载的脚本作为前一个脚本的回调参数传入，如：
* whir.res.loadJs("jquery", "//cdn.bootcss.com/jquery/1.12.4/jquery.min.js",
* function () {
* whir.res.loadJs("turntable", "Script/whir.turntable.js", null);
* }
* );
* 3.加载css，如：whir.res.loadCss("css", "/Style/css_whir.css", null);
*/
var whir = window.whir || {};
function getRelativePath(url,level){
var urlarray = url.split("/");
var resulturl = "";
for(var i=0;i<urlarray.length-level;i++){
resulturl += urlarray[i]+"/";
}
return resulturl;
}
whir.res = {
pageVersion: "0.0.1", //页面版本，也由页面输出，用于刷新localStorage缓存
//动态加载js文件并缓存
loadJs: function (name, url, callback) {
if (window.localStorage) {
var xhr;
var js = localStorage.getItem(name);
if (js == null || js.length == 0 || this.pageVersion != localStorage.getItem("version")) {
if (window.ActiveXObject) {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
}
if (xhr != null) {
xhr.open("GET", url);
xhr.send(null);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
js = xhr.responseText;
localStorage.setItem(name, js);
localStorage.setItem("version", whir.res.pageVersion);
js = js == null ? "" : js;
whir.res.writeJs(js);
if (callback != null) {
callback(); //回调，执行下一个引用
}
}
};
}
} else {
whir.res.writeJs(js);
if (callback != null) {
callback(); //回调，执行下一个引用
}
}
} else {
whir.res.linkJs(url);
}
},
loadCss: function (name, url) {
if (window.localStorage) {
var xhr;
var css = localStorage.getItem(name);
if (css == null || css.length == 0 || this.pageVersion != localStorage.getItem("version")) {
if (window.ActiveXObject) {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
}
if (xhr != null) {
xhr.open("GET", url);
xhr.send(null);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
css = xhr.responseText;
localStorage.setItem(name, css);
localStorage.setItem("version", whir.res.pageVersion);
css = css == null ? "" : css;
css = css.replace(/\..\/fonts\//g, getRelativePath(url,2)+"fonts/"); //css里的font路径需单独处理
whir.res.writeCss(css);
}
};
}
} else {
css = css.replace(/\..\/fonts\//g, getRelativePath(url,2)+"fonts/"); //css里的font路径需单独处理
whir.res.writeCss(css);
}
} else {
whir.res.linkCss(url);
}
},
//往页面写入js脚本
writeJs: function (text) {
var head = document.getElementsByTagName('HEAD').item(0);
var link = document.createElement("script");
link.type = "text/javascript";
link.innerHTML = text;
head.appendChild(link);
},
//往页面写入css样式
writeCss: function (text) {
var head = document.getElementsByTagName('HEAD').item(0);
var link = document.createElement("style");
link.type = "text/css";
link.innerHTML = text;
head.appendChild(link);
},
//往页面引入js脚本
linkJs: function (url) {
var head = document.getElementsByTagName('HEAD').item(0);
var link = document.createElement("script");
link.type = "text/javascript";
link.src = url;
head.appendChild(link);
},
//往页面引入css样式
linkCss: function (url) {
var head = document.getElementsByTagName('HEAD').item(0);
var link = document.createElement("link");
link.type = "text/css";
link.rel = "stylesheet";
link.rev = "stylesheet";
link.media = "screen";
link.href = url;
head.appendChild(link);
}
};