mongoose doc.save fails without error in schema method - node.js

Question

Using mongoose i am doing:
var postSchecma = mongoose.Schema({
title: String,
body: String,
link: String,
voting: {
has: {
type: Boolean,
default:
false
},
canVoteFor: [mongoose.Schema.Types.Mixed],
votedFor:{},
voteDates:{}
},
comments: [mongoose.Schema.Types.Mixed],
date: {
type: mongoose.Schema.Types.Mixed,
default:
new Date().getTime()
}
}, {
strict: false,
safe:true
})
and
postSchecma.methods.vote = function(voteFor, callback) {
var self = this;
if(self.voting.canVoteFor.indexOf(voteFor) < 0) {
callback(new Error('Error: Invalid Thing To Vote For'));
return;
}
this.voting.voteDates[voteFor].push(new Date().getTime())
this.voting.votedFor[voteFor]++
s = this;
this.save(function(err) {
if(err) {
callback(err)
}
console.log(err);
console.log("this:"+ s);
callback(s)
})
}
in postSchecma.methods.vote the value of this.voting.votedFor[voteFor] is correct. but when I query the db it is the old value. if it helps i am using the db in 2 files and the methods may not be exact duplicates.
I also know it is something with mongoose because I can change the record to a different value with a mongoDB GUI and it works fine.
let me know if you need any more info,
thanks,
Porad

Answer 1

Any field in your schema that's defined as {} or Mixed must be explicitly marked as modified or Mongoose won't know that it has changed and that Mongoose needs to save it.
In this case you'd need to add the following prior to the save:
this.markModified('voting.voteDates');
this.markModified('voting.votedFor');
See docs on Mixed here.

Answer 2

Turns out that this also sometimes applies for non-Mixed items, as I painfully discovered. If you reassign an entire sub-object, you need to use markModified there as well. At least... sometimes. I didn't use to get this error, and then I did, without changing any relevant code. My guess is that it was a mongoose version upgrade.
Example! Say you have...
personSchema = mongoose.Schema({
name: {
first: String,
last: String
}
});
...and then you call...
Person.findById('whatever', function (err, person) {
person.name = {first: 'Malcolm', last: 'Ocean'};
person.save(function (err2) {
// person.name will be as it was set, but this won't persist
// to the database
});
});
...you will have a bad time unless you call person.markModified('name') before save
(or alternatively, call both person.markModified('name.first') and person.markModified('name.last') ...but that seems clearly inferior here)