我的模块加载系统 v20

by 司徒正美

at 2012-12-06 10:02:00

original http://www.cnblogs.com/rubylouvre/archive/2012/12/06/2803395.html

mass Framework的加载器v20发布，本版本的更新如下：

参考requireJS的实现，去掉iframe的加载机制
内部install方法改名更语义的fireFactory
最后回调的临时模块名的前缀由"@cb"改成"cb"，防止在旧式IE使用userData时出错

从v19起，define与require已经完全独立成全局函数，不再依赖于$了，成为一个纯粹的加载器。

示例，加载一个UI组件的模块：

它在firebug中打印调试信息如下：

可以看到它是非常易于调试的。如果想屏蔽它们，将$.config.level = 8就行了。

它的加载请求图如下，可以看到它是货真价实的并行加载器。如果一个模块的直接依赖不超过浏览器的最大请求数，它会同时发出请求进行处理。

IE10的情况

void function( global, DOC ){
var $$ = global.$//保存已有同名变量
var rmakeid = /(#.+|\W)/g;
var NsKey = DOC.URL.replace( rmakeid,"")
var NsVal = global[ NsKey ];//公共命名空间
var W3C = DOC.dispatchEvent //w3c事件模型
var HTML = DOC.documentElement;
var HEAD = DOC.head || DOC.getElementsByTagName( "head" )[0]
var loadings = [];//正在加载中的模块列表
var stack = []; //储存需要绑定ID与factory对应关系的模块（标准浏览器下，先parse的script节点会先onload）
var mass = 1;//当前框架的版本号
var postfix = "";//用于强制别名
var cbi = 1e5 ; //用于生成回调函数的名字
var all = "lang_fix,lang,support,class,flow,query,data,node,attr,css_fix,css,event_fix,event,ajax,fx"
var class2type = {
"[object HTMLDocument]" : "Document",
"[object HTMLCollection]" : "NodeList",
"[object StaticNodeList]" : "NodeList",
"[object IXMLDOMNodeList]": "NodeList",
"[object DOMWindow]" : "Window" ,
"[object global]" : "Window" ,
"null" : "Null" ,
"NaN" : "NaN" ,
"undefined" : "Undefined"
}
var toString = class2type.toString, basepath
function $( expr, context ){//新版本的基石
if( $.type( expr,"Function" ) ){ //注意在safari下,typeof nodeList的类型为function,因此必须使用$.type
return $.require( all+",ready", expr );
}else{
if( !$.fn )
throw "node module is required!"
return new $.fn.init( expr, context );
}
}
//多版本共存
if( typeof NsVal !== "function"){
NsVal = $;//公用命名空间对象
NsVal.uuid = 1;
}
if(NsVal.mass !== mass ){
NsVal[ mass ] = $;//保存当前版本的命名空间对象到公用命名空间对象上
if(NsVal.mass || ($$ && $$.mass == null)) {
postfix = ( mass + "" ).replace(/\D/g, "" ) ;//是否强制使用多库共存
}
}else{
return;
}
/
* 糅杂，为一个对象添加更多成员
* @param {Object} receiver 接受者
* @param {Object} supplier 提供者
* @return {Object} 目标对象
*/
var has = Object.prototype.hasOwnProperty
function mix( receiver, supplier ){
var args = Array.apply([], arguments ),i = 1, key,//如果最后参数是布尔，判定是否覆写同名属性
ride = typeof args[args.length - 1] == "boolean" ? args.pop() : true;
if(args.length === 1){//处理$.mix(hash)的情形
receiver = !this.window ? this : {} ;
i = 0;
}
while((supplier = args[i++])){
for ( key in supplier ) {//允许对象糅杂，用户保证都是对象
if ( has.call(supplier,key) && (ride || !(key in receiver))) {
receiver[ key ] = supplier[ key ];
}
}
}
return receiver;
}

mix( $, {//为此版本的命名空间对象添加成员
html: HTML,
head: HEAD,
mix: mix,
rword: /[^, ]+/g,
mass: mass,//大家都爱用类库的名字储存版本号，我也跟风了
"@bind": W3C ? "addEventListener" : "attachEvent",
//将内部对象挂到window下，此时可重命名，实现多库共存 name String 新的命名空间
exports: function( name ) {
$$ && ( global.$ = $$ );//多库共存
name = name || $.config.nick;//取得当前简短的命名空间
$.config.nick = name;
global[ NsKey ] = NsVal;
return global[ name ] = this;
},
/
* 数组化
* @param {ArrayLike} nodes 要处理的类数组对象
* @param {Number} start 可选。要抽取的片断的起始下标。如果是负数，从后面取起
* @param {Number} end 可选。规定从何处结束选取
* @return {Array}
/
slice: function ( nodes, start, end ) {
var ret = [], n = nodes.length;
if(end === void 0 || typeof end == "number" && isFinite(end)){
start = parseInt(start,10) || 0;
end = end == void 0 ? n : parseInt(end, 10);
if(start < 0){
start += n;
}
if(end > n){
end = n;
}
if(end < 0){
end += n;
}
for (var i = start; i < end; ++i) {
ret[i - start] = nodes[i];
}
}
return ret;
},
/**
* 用于取得数据的类型（一个参数的情况下）或判定数据的类型（两个参数的情况下）
* @param {Any} obj 要检测的东西
* @param {String} str 可选，要比较的类型
* @return {String|Boolean}
/
type: function ( obj, str ){
var result = class2type[ (obj == null || obj !== obj ) ? obj : toString.call( obj ) ] || obj.nodeName || "#";
if( result.charAt(0) === "#" ){//兼容旧式浏览器与处理个别情况,如window.opera
//利用IE678 window == document为true,document == window竟然为false的神奇特性
if( obj == obj.document && obj.document != obj ){
result = "Window"; //返回构造器名字
}else if( obj.nodeType === 9 ) {
result = "Document";//返回构造器名字
}else if( obj.callee ){
result = "Arguments";//返回构造器名字
}else if( isFinite( obj.length ) && obj.item ){
result = "NodeList"; //处理节点集合
}else{
result = toString.call( obj ).slice( 8, -1 );
}
}
if( str ){
return str === result;
}
return result;
},
//$.log(str, showInPage=true, 5 )
//level Number，通过它来过滤显示到控制台的日志数量。0为最少，只显示最致命的错误，
//7则连普通的调试消息也打印出来。显示算法为 level <= $.config.level。
//这个$.colre.level默认为9。下面是level各代表的含义。
//0 EMERGENCY 致命错误,框架崩溃
//1 ALERT 需要立即采取措施进行修复
//2 CRITICAL 危急错误
//3 ERROR 异常
//4 WARNING 警告
//5 NOTICE 通知用户已经进行到方法
//6 INFO 更一般化的通知
//7 DEBUG 调试消息
log: function (str){
var show = true, page = false
for(var i = 1 ; i < arguments.length; i++){
var el = arguments[i]
if(typeof el == "number"){
show = el <= $.config.level
}else if(el === true){
page = true;
}
}
if(show){
if( page === true ){
$.require( "ready", function(){
var div = DOC.createElement( "pre" );
div.className = "mass_sys_log";
div.innerHTML = str +"";//确保为字符串
DOC.body.appendChild(div);
});
}else if( global.console ){
global.console.log( str );
}
}
return str
},
//主要用于建立一个从元素到数据的引用，具体用于数据缓存，事件绑定，元素去重
getUid: global.getComputedStyle ? function( obj ){//IE9+,标准浏览器
return obj.uniqueNumber || ( obj.uniqueNumber = NsVal.uuid++ );
}: function( obj ){
if(obj.nodeType !== 1){//如果是普通对象，文档对象，window对象
return obj.uniqueNumber || ( obj.uniqueNumber = NsVal.uuid++ );
}//注：旧式IE的XML元素不能通过el.xxx = yyy 设置自定义属性
var uid = obj.getAttribute("uniqueNumber");
if ( !uid ){
uid = NsVal.uuid++;
obj.setAttribute( "uniqueNumber", uid );
}
return +uid;//确保返回数字
},
/
* 生成键值统一的对象，用于高速化判定
* @param {Array|String} array 如果是字符串，请用","或空格分开
* @param {Number} val 可选，默认为1
* @return {Object}
/
oneObject : function( array, val ){
if( typeof array == "string" ){
array = array.match( $.rword ) || [];
}
var result = {}, value = val !== void 0 ? val :1;
for(var i = 0, n = array.length; i < n; i++){
result[ array[i] ] = value;
}
return result;
},
config: function( settings ) {
var kernel = $.config;
for ( var p in settings ) {
if (!settings.hasOwnProperty( p ))
continue
var prev = kernel[ p ];
var curr = settings[ p ];
if (prev && p === "alias") {
for (var c in curr) {
if (curr.hasOwnProperty( c )) {
var prevValue = prev[ c ];
var currValue = curr[ c ];
if( prevValue && prev !== curr ){
throw new Error(c + "不能重命名")
}
prev[ c ] = currValue;
}
}
} else {
kernel[ p ] = curr;
}
}
return this
}
});
(function(scripts, cur){
cur = scripts[ scripts.length - 1 ];
var url = cur.hasAttribute ? cur.src : cur.getAttribute( "src", 4 );
url = url.replace(/[?#]./, "");
var a = cur.getAttribute("debug");
var b = cur.getAttribute("storage");
var kernel = $.config;
kernel.debug = a == "true" || a == "1";
kernel.storage = b == "true"|| b == "1";
basepath = kernel.base = url.substr( 0, url.lastIndexOf("/") ) +"/";
kernel.nick = cur.getAttribute("nick") || "$";
kernel.erase = cur.getAttribute("erase") || "erase";
kernel.alias = {};
kernel.level = 9;

})(DOC.getElementsByTagName( "script" ));
$.noop = $.error = function(){};

"Boolean,Number,String,Function,Array,Date,RegExp,Window,Document,Arguments,NodeList".replace( $.rword, function( name ){
class2type[ "[object " + name + "]" ] = name;
});

function parseURL(url, parent, ret){
//[]里面，不是开头的-要转义，因此要用/^[-a-z0-9$]{2,}$/i而不是/^[a-z0-9-$]{2,}
//别名至少两个字符；不用汉字是避开字符集的问题
if( /^(mass|ready)$/.test(url)){//特别处理ready标识符
return [url, "js"];
}
if(/^[-a-z0-9$]{2,}$/i.test(url) && $.config.alias[url] ){
ret = $.config.alias[url];
}else{
parent = parent.substr( 0, parent.lastIndexOf('/') )
if(/^(\w+)(\d)?:./.test(url)){ //如果用户路径包含协议
ret = url
}else {
var tmp = url.charAt(0);
if( tmp !== "." && tmp != "/"){ //相对于根路径
ret = basepath + url;
}else if(url.slice(0,2) == "./"){ //相对于兄弟路径
ret = parent + url.substr(1);
}else if( url.slice(0,2) == ".."){ //相对于父路径
var arr = parent.replace(/\/$/,"").split("/");
tmp = url.replace(/..\//g,function(){
arr.pop();
return "";
});
ret = arr.join("/")+"/"+tmp;
}else if(tmp == "/"){
ret = parent + url
}else{
throw new Error("不符合模块标识规则")
}
}
}
var ext = "js";
tmp = ret.replace(/[?#]./, "");
if(/.(\w+)$/.test( tmp )){
ext = RegExp.$1;
}
if( ext!="css" &&tmp == ret && !/.js$/.test(ret)){//如果没有后缀名会补上.js
ret += ".js";
}
return [ret, ext];
}

$.mix({
//绑定事件(简化版)
bind: W3C ? function( el, type, fn, phase ){
el.addEventListener( type, fn, !!phase );
return fn;
} : function( el, type, fn ){
el.attachEvent && el.attachEvent( "on"+type, fn );
return fn;
},
unbind: W3C ? function( el, type, fn, phase ){
el.removeEventListener( type, fn || $.noop, !!phase );
} : function( el, type, fn ){
if ( el.detachEvent ) {
el.detachEvent( "on" + type, fn || $.noop );
}
},
//移除指定或所有本地储存中的模块
erase : function( id, v ){
if(id == void 0){
Storage.clear();
}else{
var old = Storage.getItem( id+"version" );
if(old && (!v || v > Number(old)) ){
Storage.removeItem( id );
Storage.removeItem( id+"deps" );
Storage.removeItem( id+"parent" );
Storage.removeItem( id+"version" );
}
}
}
});
//================================localStorage===============================
var Storage = $.oneObject("setItem,getItem,removeItem,clear",$.noop);
if( global.localStorage){
Storage = localStorage;
}else if( HTML.addBehavior){
HTML.addBehavior('#default#userData');
HTML.save("massdata");
//https://github.com/marcuswestin/store.js/issues/40#issuecomment-4617842
//在IE67它对键名非常严格,不能有特殊字符,否则抛throwed an This name may not contain the '~' character: key-->~<--
var rstoragekey = new RegExp("[!"#$%&'()+,/\\:;<=>?@[\]^`{|}~]", "g");
function curry(fn) {
return function(a, b) {
HTML.load("massdata");
a = String(a).replace(rstoragekey, function(w){
return w.charCodeAt(0);
});
var result = fn( a, b );
HTML.save("massdata");
return result
}
}
Storage = {
setItem : curry(function(key, val){
HTML.setAttribute(key, val);
}),
getItem: curry(function(key){
return HTML.getAttribute(key);
}),
removeItem: curry(function(key){
HTML.removeAttribute(key);
}),
clear: function(){
var attributes = HTML.XMLDocument.documentElement.attributes
for (var i=0, attr; attr=attributes[i]; i++) {
HTML.removeAttribute(attr.name)
}
}
}
}
var rerase = new RegExp("(?:^| )" + $.config.erase + "(?:(?:=([^;]))|;|$)")
var match = String(DOC.cookie).match( rerase );
//读取从后端过来的cookie指令，转换成一个对象，键名为模块的URL，值为版本号（这是一个时间戮）
if(match && match[1]){
try{
var obj = eval("0,"+match[1]);
for(var i in obj){//$.erase会版本号比现在小的模块从本地储存中删掉
$.erase(i, obj[i])
}
}catch(e){}
}

//============================加载系统===========================
var modules = $.modules = {
ready:{ },
mass: {
state: 2,
exports: $
}
};
function getCurrentScript(){
if(DOC.currentScript){
return DOC.currentScript.src
}
var nodes = DOC.getElementsByTagName("script")
for (var i = 0, node; node = nodes[i++];) {
if (!node.pass && node.readyState === "interactive") {
return node.pass = node.src;
}
}
}
//检测是否存在循环依赖
function checkCycle( deps, nick ){
for(var id in deps){
if( deps[id] == "司徒正美" &&( id == nick || checkCycle(modules[id].deps, nick))){
return true;
}
}
}
//检测此JS模块的依赖是否都已安装完毕,是则安装自身
function checkDeps(){
loop:
for ( var i = loadings.length, id; id = loadings[ --i ]; ) {
var obj = modules[ id ], deps = obj.deps;
for( var key in deps ){
if( deps.hasOwnProperty( key ) && modules[ key ].state != 2 ){
continue loop;
}
}
//如果deps是空对象或者其依赖的模块的状态都是2
if( obj.state != 2){
loadings.splice( i, 1 );//必须先移除再安装，防止在IE下DOM树建完后手动刷新页面，会多次执行它
fireFactory( obj.id, obj.args, obj.factory );
checkDeps();
}
}
}
function checkFail( node, error ){
var id = node.src;
node.onload = node.onreadystatechange = node.onerror = null;
if( error || !modules[ id ].state ){
if(error){//注意，在标准浏览器下通过!modules[ id ].state检测可能不精确，这时移出节点会出错
HEAD.removeChild(node)
}
$.log("加载 "+ id +" 失败", 7);
}else{
return true;
}
}
function loadJS( url ){
var node = DOC.createElement("script")
node.onload = node.onreadystatechange = function(){
if(/loaded|complete|undefined/i.test(node.readyState) ){
//mass Framework会在checkFail把它上面的回调清掉
//因为在IE9-10, opera中，它们同时支持onload，onreadystatechange，以防重复执行factory.delay
var factory = stack.pop() ;
factory && factory.delay(node.src)
if( checkFail(node) ){
$.log("已成功加载 "+node.src, 7);
}
}
}
node.onerror = function(){
checkFail(node, true)
}
node.src = url
$.log("正准备加载 "+node.src, 7)
HEAD.insertBefore(node, HEAD.firstChild)
}

//请求模块（依赖列表,模块工厂,加载失败时触发的回调）
window.require = $.require = function( list, factory, parent ){
var deps = {}, // 用于检测它的依赖是否都为2
args = [], // 用于依赖列表中的模块的返回值
dn = 0, // 需要安装的模块数
cn = 0, // 已安装完的模块数
id = parent || "cb"+ ( cbi++ ).toString(32);
parent = parent || basepath
String(list).replace( $.rword, function(el){
var array = parseURL(el, parent ), url = array[0];
if(array[1] == "js"){
dn++
loadStorage( id )
if( !modules[ url ] ){
modules[ url ] = {
id: url,
parent: parent,
exports: {}
};
loadJS( url );
}else if( modules[ url ].state === 2 ){
cn++;
}
if( !deps[ url ] ){
args.push( url );
deps[ url ] = "司徒正美";//去重
}
}else if(array[1] === "css"){
loadCSS( url );
}
});
//创建或更新模块的状态
modules[id] = {
id: id,
factory: factory,
deps: deps,
args: args,
state: 1
}
if( dn === cn ){//如果需要安装的等于已安装好的
fireFactory( id, args, factory );//装配到框架中
checkDeps();
return
}
//在正常情况下模块只能通过checkDeps执行
loadings.unshift( id );
}
//定义模块
var rcomment = /\/*(?:[^]|*+[^\/])*+\/|\/\/./g
window.define = $.define = function( id, deps, factory ){//模块名,依赖列表,模块本身
var args = Array.apply([],arguments), id
if(typeof id == "string"){
id = args.shift();
}
if( typeof args[0] === "boolean" ){//用于文件合并, 在标准浏览器中跳过补丁模块
if( args[0] ){
return;
}
args.shift()
}
if(typeof args[0] == "function"){
args.unshift([]);
}
id = modules[id] && modules[id].state == 2 ? id : getCurrentScript();
factory = args[1];
factory.id = id;//用于调试
factory.delay = function( id ){
args.push( id );
if( checkCycle(modules[id].deps, id)){
throw new Error( id +"模块与之前的某些模块存在循环依赖")
}
if( $.config.storage && !Storage.getItem( id ) ){
Storage.setItem( id, factory.toString().replace(rcomment,""));
Storage.setItem( id+"deps", args[0]+"");
Storage.setItem( id+"parent", id);
Storage.setItem( id+"version", new Date - 0);
}
delete factory.delay;//释放内存
require.apply(null, args); //0,1,2 --> 1,2,0
}
if(id ){
factory.delay(id,args)
}else{//先进先出
stack.push( factory )
}
}
$.require.amd = modules
function loadStorage( id ){
var factory = Storage.getItem( id );
if( $.config.storage && factory && !modules[id]){
var parent = Storage.getItem(id+"parent");
var deps = Storage.getItem(id+"deps");
deps = deps ? deps.match( $.rword ) : "";
modules[ id ] ={
id: id,
parent: parent,
exports: {},
state: 1
};
require(deps, Function("return "+ factory )(), id) //0,1,2 --> 1,2,0
}
}
function loadCSS(url){
var id = url.replace(rmakeid,"");
if (DOC.getElementById(id))
return
var link = DOC.createElement("link");
link.charset = "utf-8";
link.rel = "stylesheet";
link.href = url;
link.type = "text/css";
link.id = id;
HEAD.insertBefore( link, HEAD.firstChild );
}
//从returns对象取得依赖列表中的各模块的返回值，执行factory, 完成模块的安装
function fireFactory( id, deps, factory ){
for ( var i = 0, array = [], d; d = deps[i++]; ) {
array.push( modules[ d ].exports );
}
var module = Object( modules[id] ), ret;
ret = factory.apply(global, array);
module.state = 2;
if( ret !== void 0 ){
modules[ id ].exports = ret
}
return ret;
}
all.replace($.rword,function(a){
$.config.alias[ "$"+a ] = basepath + a + ".js";
});
//domReady机制
var readyFn, ready = W3C ? "DOMContentLoaded" : "readystatechange" ;
function fireReady(){
modules.ready.state = 2;
checkDeps();
if( readyFn ){
$.unbind( DOC, ready, readyFn );
}
fireReady = $.noop;//隋性函数，防止IE9二次调用checkDeps
};
function doScrollCheck() {
try {
HTML.doScroll( "left" ) ;
fireReady();
} catch(e) {
setTimeout( doScrollCheck, 31 );
}
};

if ( DOC.readyState === "complete" ) {
fireReady();//如果在domReady之外加载
}else {
$.bind( DOC, ready, readyFn = function(){
if ( W3C || DOC.readyState === "complete" ){
fireReady();
}
});
if( HTML.doScroll && self.eval === parent.eval)
doScrollCheck();
}

global.VBArray && ("abbr,article,aside,audio,bdi,canvas,data,datalist,details,figcaption,figure,footer," +
"header,hgroup,mark,meter,nav,output,progress,section,summary,time,video").replace( $.rword, function( tag ){
DOC.createElement(tag);
});

//https://developer.mozilla.org/en/DOM/window.onpopstate
$.bind( global, "popstate", function(){
NsKey = DOC.URL.replace(rmakeid,"");
$.exports();
});
$.exports( $.config.nick + postfix );//防止不同版本的命名空间冲突
/combine modules/

}( self, self.document );//为了方便在VS系列实现智能提示,把这里的this改成self或window

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