promise相关

转换callbak到promise形式

/**
 * 转换callbak到promise形式
 * ex1:有一个api getGeo(success,fail);
 * 使用后
 * callbackToPromise.call(getGeo,arg1,arg2,"|",arg-2,arg-1).then ...
 * ex2:callbackToPromise.call({callback:api.getGeo,scope:api},arg1,arg2,"|",arg-2,arg-1).then...
 * @returns {Promise}
 */
var callbackToPromise = function(){
    var args = Array.prototype.slice.call(arguments);
    var func = this;
    return new Promise(function(resolve,reject){
        var splitIndex = _.indexOf(args,"|");
        if(splitIndex==-1) {
            splitIndex=args.length;
        }
        args.splice(splitIndex,1,resolve,reject)
        if(!func) {
            resolve("调用的方法不存在")
        }
        
        if(typeof func == "function") {
            func.apply(null,args);
        }else if(func.callback){
            func.callback.apply(func.scope,args)
        }
    })
}