Mongoose self referenced schema not creating ObjectId for all sub documents - node.js

Question

I have a Schema in mongoose that have a self referenced field, like this:
var mongoose = require('mongoose');
var CollectPointSchema = new mongoose.Schema({
name: {type: String},
collectPoints: [ this ]
});
when a CollectPoint object is inserted:
{
"name": "Level 1"
}
it's ok, the result is like expected:
{
"_id": "58b36c83b7134680367b2547",
"name": "Level 1",
"collectPoints": []
}
But when I insert self referenced sub documents,
{
"name": "Level 1",
"collectPoints": [{
"name": "Level 1.1"
}]
}
It gives me this:
{
"_id": "58b36c83b7134680367b2547",
"name": "Level 1",
"collectPoints": [{
"name": "Level 1.1"
}]
}
Where is the _id of the child CollectPointSchema? I need this _id.

Answer 1

You should build a new object when declaring your embedded CollectPoint items :
var data = new CollectPoint({
name: "Level 1",
collectPoints: [
new CollectPoint({
name: "Level 1.1",
collectPoints: []
})
]
});
This way the _id and collectPoints will be created by the instanciation of CollectPoint otherwise, you are just creating a plain JSONObject.
To avoid those kind of issues, build a validator for your array that will trigger an error if its items have wrong type :
var CollectPointSchema = new mongoose.Schema({
name: { type: String },
collectPoints: {
type: [this],
validate: {
validator: function(v) {
if (!Array.isArray(v)) return false
for (var i = 0; i < v.length; i++) {
if (!(v[i] instanceof CollectPoint)) {
return false;
}
}
return true;
},
message: 'bad collect point format'
}
}
});
This way the following will trigger an error :
var data = new CollectPoint({
name: "Level 1",
collectPoints: [{
name: "Level 1.1",
collectPoints: []
}]
});