Node.js Mongoose：自定义类型扩充模式

我想使用mongoose自定义类型的强大功能，但有一个问题我找不到解决方法。基本上，我们需要使用以下模式为日期保留时区

{
   date: {type: Date}, //UTC date for ease of use
   zone: {type: String} //Initial timezone that allows to restore local date
}

我已经用

cast

函数为标准日期字符串返回

{date:，zone:}

对象

2014-10-24T14:00:00+0500

（不确定这是否有效，所以欢迎任何建议）。 问题是给定以下代码

//Schema is extended with LocalDate already
var test = new Schema({
  birthday: {type: Schema.Types.LocalDate}
});

var doc = new test({birthday: '2014-10-24T14:00:00+0500'});
doc.save(function(err){
  //err is null here. 
});

已插入数据库且具有_id的文档。但根本不保存生日路径

看起来好像从未调用过

cast

。下面是它的定义

module.exports = function(mongoose){
  var Schema = mongoose.Schema;
  var Types = mongoose.Types;
  var SchemaType = mongoose.SchemaType;
  function LocalDate(){
     SchemaType.call(this, key, options);
  }
  LocalDate.prototype.__proto__ = SchemaType.prototype;

  //Here comes checkRequired, $conditionalHandlers etc. which seem to be irrelevant here

   LocalDate.prototype.cast = function(val, scope, init){
     console.log('casting LocalDate'); //Never logged
     if (null === val || '' === val) return null;

     if (_.isObject(val)){ 
      return fromObject(val);
     }
     throw new SchemaType.CastError('LocalDate', val);
   };

     Schema.Types.LocalDate = LocalDate;
     Types.LocalDate = LocalDate;
     return LocalDate;
}

你知道这里有什么问题吗