updating embedded sub documents - mongoose - node.js

Question

I have the following schemas:
var reviewSchema = new mongoose.Schema({
comments : String,
rating : String,
submitted_date: {type: Date, default: Date.now},
numAgreed : Number,
numDisagreed : Number
});
var userSchema = new mongoose.Schema({
firstName : String,
lastName : String,
numRatings : Number,
averageRating: Number,
reviews : [reviewSchema]
});
I am implementing an agree function (increment number of those who agreed with the review) for every review as follows:
exports.processAgree = function(req,res){
var firstName = req.body.firstName;
var lastName = req.body.lastName;
var index = req.body.index;
User.findOne({firstName:firstName,lastName:lastName}).lean().exec(function(err,user) {
if (err) {
throw err;
}
else{
user.reviews[index].numAgreed++;
user.markModified('reviews');
user.save(function (err) {
if (err) throw err;
});
}
});
};
However, I get the error:
reviewedUser.markModified('reviews');
^
TypeError: Object #<Object> has no method 'markModified'
I searched through stackoveflow and have seen responses to this issue but they don't to work in my case. E.g. There was a response at How to update an embedded document within an embedded document in mongoose?
The solution suggests to declare child schemas before the parent schemas which is the case in my situation.
Please let me know if more information is required to help.
Thanks.

Answer 1

As Johnny said, you should remove the call to lean method on Query.
Such that your code would look like
User.findOne({firstName:firstName,lastName:lastName}).exec(function(err,user) {
if (err) {
throw err;
}
else{
user.reviews[index].numAgreed++;
user.markModified('reviews');
user.save(function (err) {
if (err) throw err;
});
}
});
Lean is used to strip all the service methods and properties from objects that come from Mongoose methods. If you don't use lean method on Query object, Mongoose will return instances of Model. Mongoose doc on lean().
And markModified method, that you are looking for, resides in Mongoose Model instance. By the way, save is in Model instance too.