Mongoose.js: Atomic update of nested properties? - node.js

Question

Using Mongoose version 3.6.4
Say I have a MongoDB document like so:
{
"_id" : "5187b74e66ee9af96c39d3d6",
"profile" : {
"name" : {
"first" : "Joe",
"last" : "Pesci",
"middle" : "Frank"
}
}
}
And I have the following schema for Users:
var UserSchema = new mongoose.Schema({
_id: { type: String },
email: { type: String, required: true, index: { unique: true }},
active: { type: Boolean, required: true, 'default': false },
profile: {
name: {
first: { type: String, required: true },
last: { type: String, required: true },
middle: { type: String }
}
}
created: { type: Date, required: true, 'default': Date.now},
updated: { type: Date, required: true, 'default': Date.now}
);
And I submit a form passing a field named: profile[name][first] with a value of Joseph
and thus I want to update just the user's first name, but leave his last and middle alone, I thought I would just do:
User.update({email: "joe#foo.com"}, req.body, function(err, result){});
But when I do that, it "deletes" the profile.name.last and profile.name.middle properties and I end up with a doc that looks like:
{
"_id" : "5187b74e66ee9af96c39d3d6",
"profile" : {
"name" : {
"first" : "Joseph"
}
}
}
So it's basically overwriting all of profile with req.body.profile, which I guess makes sense. Is there any way around it without having to be more explicit by specifying my fields in the update query instead of req.body?

Answer 1

You are correct, Mongoose converts updates to $set for you. But this doesn't solve your issue. Try it out in the mongodb shell and you'll see the same behavior.
Instead, to update a single deeply nested property you need to specify the full path to the deep property in the $set.
User.update({ email: 'joe#foo.com' }, { 'profile.name.first': 'Joseph' }, callback)

Answer 2

One very easy way to solve this with Moongose 4.1 and the flat package:
var flat = require('flat'),
Schema = mongoose.Schema,
schema = new Schema(
{
name: {
first: {
type: String,
trim: true
},
last: {
type: String,
trim: true
}
}
}
);
schema.pre('findOneAndUpdate', function () {
this._update = flat(this._update);
});
mongoose.model('User', schema);
req.body (for example) can now be:
{
name: {
first: 'updatedFirstName'
}
}
The object will be flattened before the actual query is executed, thus $set will update only the expected properties instead of the entire name object.

Answer 3

I think you are looking for $set
http://docs.mongodb.org/manual/reference/operator/set/
User.update({email: "joe#foo.com"}, { $set : req.body}, function(err, result){});
Try that

Answer 4

Maybe it's a good solution - add option to Model.update, that replace nested objects like:
{field1: 1, fields2: {a: 1, b:2 }} => {'field1': 1, 'field2.a': 1, 'field2.b': 2}
nestedToDotNotation: function(obj, keyPrefix) {
var result;
if (keyPrefix == null) {
keyPrefix = '';
}
result = {};
_.each(obj, function(value, key) {
var nestedObj, result_key;
result_key = keyPrefix + key;
if (!_.isArray(value) && _.isObject(value)) {
result_key += '.';
nestedObj = module.exports.nestedToDotNotation(value, result_key);
return _.extend(result, nestedObj);
} else {
return result[result_key] = value;
}
});
return result;
}
});
need improvements circular reference handling, but this is really useful when working with nested objects
I'm using underscore.js here, but these functions easily can be replaced with other analogs