Mongoose填充单个虚拟字段

Question

我有以下架构(CoffeeScript):

adSchema = new mongoose.Schema({
  ...
  user : { type: mongoose.Schema.Types.ObjectId, ref: 'User' }
  ...
},
{
  toObject: { virtuals: true },
  toJSON: { virtuals: true }
})

userSchema = new mongoose.Schema({
  username : String
  email :
    type : String
    required : true
    index :
      unique : true
  adverts : [{ type: mongoose.Schema.Types.ObjectId, ref: 'Advert' }]
},
{
  toObject: { virtuals: true }
  toJSON: { virtuals: true }
})

userSchema.virtual('screenname').get () ->
  if this.username? then this.username else this.email.split('@')[0]+'@...'

然后我尝试获取一堆记录并填充用户:

getAdvertPage = (obj, fn) ->
  page_size = 10
  query =
    tags : obj.tag
  Advert.count query, (err, count) ->
    Advert.find(query)
    .sort(obj.sort)
    .skip((obj.page-1)*page_size)
    .limit(page_size)
    .populate('user', 'screenname')
    .exec (err, ads) ->
      ads.lastPage = (obj.page-1)*page_size + page_size >= count
      fn err, ads

但我只想要用户的屏幕名称而不是其他任何东西(这是一个虚拟字段).但是,这会导致错误:

Cannot call method 'split' of undefined

如果我在填充中包含电子邮件它工作正常,但我不想将电子邮件发送到客户端.有没有办法只填充虚拟字段？

Answer 1

由于您对'screenname'的虚拟getter中的字段'email'和'username'有依赖关系,请尝试填充screenname,email和username.

...
.populate('user', 'screenname, email, username')
...

顺便说一句,您不应该在虚拟getter中实现业务逻辑以避免这种情况.考虑创建另一个虚拟.