l.js is another simple/tiny javascript/css loader
此脚本不应直接安装，它是一个供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.greasyfork.icu/scripts/23419/634829/ljs.js
//https://github.com/jae-jae/l.js
;(function(window, undefined){
/*
* script for js/css parallel loading with dependancies management
* @author Jonathan Gotti < jgotti at jgotti dot net >
* @licence dual licence mit / gpl
* @since 2012-04-12
* @todo add prefetching using text/cache for js files
* @changelog
* - 2016-08-22 - remove global eval and fix issue #13
* - 2014-06-26 - bugfix in css loaded check when hashbang is used
* - 2014-05-25 - fallback support rewrite + null id bug correction + minification work
* - 2014-05-21 - add cdn fallback support with hashbang url
* - 2014-05-22 - add support for relative paths for stylesheets in checkLoaded
* - 2014-05-21 - add support for relative paths for scripts in checkLoaded
* - 2013-01-25 - add parrallel loading inside single load call
* - 2012-06-29 - some minifier optimisations
* - 2012-04-20 - now sharp part of url will be used as tag id
* - add options for checking already loaded scripts at load time
* - 2012-04-19 - add addAliases method
* @note coding style is implied by the target usage of this script not my habbits
*/
var isA = function(a,b){ return a instanceof (b || Array);}
//-- some minifier optimisation
, D = document
, getElementsByTagName = 'getElementsByTagName'
, length = 'length'
, readyState = 'readyState'
, onreadystatechange = 'onreadystatechange'
//-- get the current script tag for further evaluation of it's eventual content
, scripts = D[getElementsByTagName]("script")
, scriptTag = scripts[scripts[length]-1]
, script = scriptTag.innerHTML.replace(/^\s+|\s+$/g,'')
;
//avoid multiple inclusion to override current loader but allow tag content evaluation
if( ! window.ljs ){
var checkLoaded = scriptTag.src.match(/checkLoaded/)?1:0
//-- keep trace of header as we will make multiple access to it
,header = D[getElementsByTagName]("head")[0] || D.documentElement
, urlParse = function(url){
var parts={}; // u => url, i => id, f = fallback
parts.u = url.replace(/#(=)?([^#]*)?/g,function(m,a,b){ parts[a?'f':'i'] = b; return '';});
return parts;
}
,appendElmt = function(type,attrs,cb){
var e = D.createElement(type), i;
if( cb ){ //-- this is not intended to be used for link
if(e[readyState]){
e[onreadystatechange] = function(){
if (e[readyState] === "loaded" || e[readyState] === "complete"){
e[onreadystatechange] = null;
cb();
}
};
}else{
e.onload = cb;
}
}
for( i in attrs ){ attrs[i] && (e[i]=attrs[i]); }
header.appendChild(e);
// return e; // unused at this time so drop it
}
,ajaxExec = function (url,success,error) {
GM_xmlhttpRequest({
method: "GET",
url:url,
onload:function(res){
//eval.call(global,res.responseText);
eval(res.responseText);
success();
},
onerror:function(){
error && error();
}
});
}
,load = function(url,cb){
if( this.aliases && this.aliases[url] ){
var args = this.aliases[url].slice(0);
isA(args) || (args=[args]);
cb && args.push(cb);
return this.load.apply(this,args);
}
if( isA(url) ){ // parallelized request
for( var l=url[length]; l--;){
this.load(url[l]);
}
cb && url.push(cb); // relaunch the dependancie queue
return this.load.apply(this,url);
}
if( url.match(/\.css\b/) ){
return this.loadcss(url,cb);
}
return this.loadjs(url,cb);
}
,exec = function(url,cb){
if( this.aliases && this.aliases[url] ){
var args = this.aliases[url].slice(0);
isA(args) || (args=[args]);
cb && args.push(cb);
return this.exec.apply(this,args);
}
if( isA(url) ){ // parallelized request
for( var l=url[length]; l--;){
this.exec(url[l]);
}
cb && url.push(cb); // relaunch the dependancie queue
return this.exec.apply(this,url);
}
if( url.match(/\.css\b/) ){
return this.loadcss(url,cb);
}
return this.execJs(url,cb);
}
,loaded = {} // will handle already loaded urls
,loader = {
aliases:{}
,loadjs: function(url,cb){
var parts = urlParse(url);
url = parts.u;
if( loaded[url] === true ){ // already loaded exec cb if any
cb && cb();
return this;
}else if( loaded[url]!== undefined ){ // already asked for loading we append callback if any else return
if( cb ){
loaded[url] = (function(ocb,cb){ return function(){ ocb && ocb(); cb && cb(); }; })(loaded[url],cb);
}
return this;
}
// first time we ask this script
loaded[url] = (function(cb){ return function(){loaded[url]=true; cb && cb();};})(cb);
cb = function(){ loaded[url](); };
appendElmt('script',{type:'text/javascript',src:url,id:parts.i,onerror:function(error){
if( parts.f ){
var c = error.currentTarget;
c.parentNode.removeChild(c);
appendElmt('script',{type:'text/javascript',src:parts.f,id:parts.i},cb);
}
}},cb);
return this;
}
,execJs:function(url,cb){
var parts = urlParse(url);
url = parts.u;
if( loaded[url] === true ){ // already loaded exec cb if any
cb && cb();
return this;
}else if( loaded[url]!== undefined ){ // already asked for loading we append callback if any else return
if( cb ){
loaded[url] = (function(ocb,cb){ return function(){ ocb && ocb(); cb && cb(); }; })(loaded[url],cb);
}
return this;
}
// first time we ask this script
loaded[url] = (function(cb){ return function(){loaded[url]=true; cb && cb();};})(cb);
cb = function(){ loaded[url](); };
/*appendElmt('script',{type:'text/javascript',src:url,id:parts.i,onerror:function(error){
if( parts.f ){
var c = error.currentTarget;
c.parentNode.removeChild(c);
appendElmt('script',{type:'text/javascript',src:parts.f,id:parts.i},cb);
}
}},cb);*/
ajaxExec(url,cb,function(){
if( parts.f ){
ajaxExec(parts.f,cb);
}
});
return this;
}
,loadcss: function(url,cb){
var parts = urlParse(url);
url = parts.u;
loaded[url] || appendElmt('link',{type:'text/css',rel:'stylesheet',href:url,id:parts.i});
loaded[url] = true;
cb && cb();
return this;
}
,load: function(){
var argv=arguments,argc = argv[length];
if( argc === 1 && isA(argv[0],Function) ){
argv[0]();
return this;
}
load.call(this,argv[0], argc <= 1 ? undefined : function(){ loader.load.apply(loader,[].slice.call(argv,1));} );
return this;
}
,exec:function(){
var argv=arguments,argc = argv[length];
if( argc === 1 && isA(argv[0],Function) ){
argv[0]();
return this;
}
exec.call(this,argv[0], argc <= 1 ? undefined : function(){ loader.exec.apply(loader,[].slice.call(argv,1));} );
return this;
}
,addAliases:function(aliases){
for(var i in aliases ){
this.aliases[i]= isA(aliases[i]) ? aliases[i].slice(0) : aliases[i];
}
return this;
}
}
;
if( checkLoaded ){
var i,l,links,url;
for(i=0,l=scripts[length];i<l;i++){
(url = scripts[i].getAttribute('src')) && (loaded[url.replace(/#.*$/,'')] = true);
}
links = D[getElementsByTagName]('link');
for(i=0,l=links[length];i<l;i++){
(links[i].rel==='stylesheet' || links[i].type==='text/css') && (loaded[links[i].getAttribute('href').replace(/#.*$/,'')]=true);
}
}
//export ljs
window.ljs = loader;
// eval inside tag code if any
}
// eval script tag content if needed
scriptTag.src && script && appendElmt('script', {innerHTML: script});
})(window);