Model.save() doesn't save embedded arrays

I have nested arrays of documents, and when I change them and do a .save() on the model it does not save the changes in the nested document.

Here are my models and schemas (some ommited for brevity):

var Votes = new mongoose.Schema({
    date: Date, 
    user_name: String,
    is_up: Boolean
});

var EventSchema = new mongoose.Schema({
  to_date: Date,
  from_date: Date,
  location: String,
  name: String,
  suggested_by: String,
  description: String,
  users: [EventUser],
  comments: [Comments],
  suggestions: [Event],
  votes: [Votes]
});

var Event = mongoose.model('Event', EventSchema);

Model before event.save() called:

{ 
     __v: 1,
    _id: 509e87e583ccbfa00e000004,
    description: 'Pfft',
    from_date: Sun Nov 11 2012 08:00:00 GMT-0500 (EST),
    location: 'Home',
    name: 'Whatever',
    suggested_by: 'No one',
    to_date: Sun Nov 11 2012 00:00:00 GMT-0500 (EST),
    votes: [],
    suggestions: 
     [ { users: [],
         comments: [],
         suggestions: [],
         votes: [],
         _id: 509e880883ccbfa00e000005,
         suggested_by: 'Some one',
         to_date: Sun Nov 11 2012 04:00:00 GMT-0500 (EST),
         from_date: Mon Nov 12 2012 00:00:00 GMT-0500 (EST),
         location: 'Home',
         name: 'Football',
         description: 'FOOTBALL!!' } ],
    comments: [],
    users: [] 
}

The same object with the nested votes right before event.save() is called.

{
   "__v":1,
   "_id":"509e87e583ccbfa00e000004",
   "description":"Pfft",
   "from_date":"2012-11-11T13:00:00.000Z",
   "location":"Home",
   "name":"Whatever",
   "suggested_by":"No one",
   "to_date":"2012-11-11T05:00:00.000Z",
   "votes":[ ],
   "suggestions":
      [ {
         "users":[],
         "comments":[ ],
         "suggestions":[ ],
         "votes":
            [{
               "is_up":true,
               "date":"2012-11-10T18:05:25.796Z",
               "user_name":"No one"
            }],
         "_id":"509e880883ccbfa00e000005",
         "suggested_by":"Some one",
         "to_date":"2012-11-11T09:00:00.000Z",
         "from_date":"2012-11-12T05:00:00.000Z",
         "location":"Home",
         "name":"Football",
         "description":"FOOTBALL!!"
      }],
   "comments":[],
   "users":[]
}

When event.save() is called, no error is thrown, but the nested votes schema inside of the nested events schema is not actually saved. If I use the same overall logic in the top level event object to save a vote, it does work.

When I looked through the code, briefly, it appears that .save() is suppose to be a shortcut for both saving new objects, as well as updating ones that already exist.

My hunch is Model.prototype._delta isn’t going deep enough to catch all nested objects, https://github.com/LearnBoost/mongoose/blob/master/lib/model.js#L529

[4lador]

I see what the issue is - classic case of the first question on the mongoose FAQ.

Thanks, it was this issue in my case ! 😃

model.myArray[index] = anyValue

becomes

model.myArray.set(index, anyValue)

[vkarpov15]

I see what the issue is - classic case of the first question on the mongoose FAQ. Mongoose can’t track changes when you set an array index directly without something like ES6 proxies or ES7 Object.observe(). Use

chart.sizes[0].lengths.set(0, "20");

or

chart.sizes[0].lengths[0] = '20';
chart.markModified('sizes.0.lengths.0');