根据配置文件加载js依赖模块

/**
* 不考虑循环依赖
* @type {Function}
*/
var loadModule = (function(){
/**
* 业务逻辑封装
* @type {{chainHead: {}, chainCurrent: {}, srcCache: {}, main: main, load: load, findModule: findModule}}
*/
var logics = {
chainHead: {}, //链表头
chainCurrent: {}, //链表当前节点
srcCache: {}, //module src 缓存
/**
* 对外接口
* @param modules 配置对象
* @param name 模块名称
* @returns {Array} 依赖模块列表，按照加载先后顺序排列
*/
main: function(modules, name){
var nameArray = [], //模块名称列表
srcArray = [], //依赖模块列表
nameStr = "", //模块名称字符串集
repeatRegex = /(^| )([\\w]+ ).*\\2/, //模块名称去重正则
i = 0;
//粗略加载所有依赖模块
this.load(modules, name)
//构造模块名称字符串集
this.chainCurrent = this.chainHead;
while(this.chainCurrent.next){
nameArray.push(this.chainCurrent.name);
this.chainCurrent = this.chainCurrent.next;
}
nameStr = nameArray.join(" ") + " "; //统一标准，末尾补一个空格
//依赖模块去重
while(repeatRegex.exec(nameStr)){
nameStr = nameStr.replace(repeatRegex, function(g0, g1, g2){
return g0.substring(0, (g0.length – g2.length));
});
}
nameStr = nameStr.substring(0, (nameStr.length – 1)); //去掉补充的多余空格
//依赖模块名称转换为模块路径
nameArray = nameStr.split(" ");
for(i = 0; i < nameArray.length; i++){
srcArray.push(this.srcCache[nameArray[i]]);
}
return srcArray;
},
/**
* 递归加载模块
* @param modules 配置对象
* @param name 模块名称
*/
load: function(modules, name){
var node = {},
module = this.findModule.call(modules, "name", name),
i = 0;
//判断模块是否存在
if(!module){
throw Error("依赖模块 " + name +" 未找到");
}
//构造模块依赖链表
node.name = name;
// node.src = module.src;
this.srcCache[name] = module.src;
node.next = this.chainHead;
this.chainHead = node;
//递归依赖
if(module.require && module.require.length){
for(i = 0;i < module.require.length; i++){
this.load(modules, module.require[i]);
}
}
},
/**
* 根据指定属性名称和属性值查找模块
* @param name 属性名称
* @param value 属性值
* @returns {*}
*/
findModule: function(name, value){
var array = this,
item = {},
i = 0;
//遍历模块
for(i = 0; i < array.length; i++){
item = array[i];
//获取指定模块
if(item && item[name] === value){
return item;
}
}
//找不到返回null
return null;
}
};
//暴露对外接口
return function(){
return logics.main.apply(logics, arguments);
};
}());
/**
* Test Usecase
* @type {*[]}
*/
var modules=[
{'name':'jquery','src':'/js/lib/jquery-1.8.3.js'},
{'name':'swfobject','src':'/js/utils/swfobject.js'},
{'name':'fancybox','src':'/js/jquery/jquery.fancybox.js','require':['jquery']},
{'name':'uploadify','src':'/js/utils/uploadify.js','require':['swfobject']},
{'name':'jqform','src':'/js/jquery/jquery.form.js','require':['jquery']},
{'name':'register','src':'/js/page/reg.js','require':['jqform']},
{'name':'login','src':'/js/page/login.js','require':['fancybox','jqform']},
{'name':'upload','src':'/js/page/upload.js','require':['fancybox','jqform','login','uploadify']}
];
console.log(loadModule(modules, "upload"));