Push to second level array in mongodb with node/express - node.js

Question

I am working on a chatroom where users can chat with each other filtered on the basis on projects. Users from the same project can talk to each other.
Here is my chat model where each document is based on project ref and has an array for the messages with user refference:
'use strict';
var mongoose = require('bluebird').promisifyAll(require('mongoose'));
var ChatSchema = new mongoose.Schema({
projectid: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Project'
},
messages: [{
userid: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User'
},
message: String,
date: {
type: Date,
default: Date.now
},
time: String
}]
});
export default mongoose.model('Chat', ChatSchema);
Now I am trying to update the messages array with new messages but I am unable to do so since past few hours. Here is what I have so far.
To get chat messages based on projects I am using:
routes:
router.get('/projectid/:id', controller.showByProject);
router.post('/projectid/:id', controller.insertMessageByProject);
controller:
// Gets the chat thread based on project id
export function showByProject(req, res) {
Chat.findAsync({projectid: req.params.id})
.then(handleEntityNotFound(res))
.then(respondWithResult(res))
.catch(handleError(res));
}
// Insert a new message in the chat based on projectid
export function insertMessageByProject(req, res) {
if (req.body._id) {
delete req.body._id;
}
Chat.findAsync({projectid: req.params.id})
.then(handleEntityNotFound(res))
.then(saveUpdates({$push: {messages: req.body}}))
.then(respondWithResult(res))
.catch(handleError(res));
}
Json Object I am sending from POSTMAN:
{
"messages":
{
"userid": "56d7967745ab81322a964927",
"message": "This is a meesage"
}
}
OR
{
"userid": "56d7967745ab81322a964927",
"message": "This is a meesage"
}
I am able to update the object if I have the object ID to the chat document itself but inside my application, I do not have the direct reference. I have tried few other ways as well but every time my application returns a 500 error.
Your help would be highly appreciated.
EDIT 1: here are the helping functions I am using generated by the angular full-stack plugin.
function respondWithResult(res, statusCode) {
statusCode = statusCode || 200;
return function(entity) {
if (entity) {
res.status(statusCode).json(entity);
}
};
}
function saveUpdates(updates) {
return function(entity) {
var updated = _.merge(entity, updates);
return updated.saveAsync()
.spread(updated => {
return updated;
});
};
}
function removeEntity(res) {
return function(entity) {
if (entity) {
return entity.removeAsync()
.then(() => {
res.status(204).end();
});
}
};
}
function handleEntityNotFound(res) {
return function(entity) {
if (!entity) {
res.status(404).end();
return null;
}
return entity;
};
}
function handleError(res, statusCode) {
statusCode = statusCode || 500;
return function(err) {
res.status(statusCode).send(err);
};
}
EDIT 2: As I mentioned in the comments, the problem was with _.Merge function which was not merging the object right, although it should have been able to update the object.
So I wrote my own function for saveUpdates as follows:
function saveUpdatesForNewChat(updates) {
return function(entity) {
var temp = entity;
temp[0].messages.push(updates);
console.log('\ntemp:');
console.log(require('util').inspect(temp, { depth: null }));
console.log('\nend of ops\n\n');
var updated = _.merge(entity, temp);
console.log('out of merge');
console.log(require('util').inspect(updated, { depth: null }));
return updated.saveAsync()
.spread(updated => {
return updated;
});
};
}
ok so I have left the console logs inside and it's perfect object to save into the database but the server still returns a 500 errors on update.

Answer 1

OK! So I have found the answer myself.
The problem was that the object returned was a result set and I was calling save on whole result set. I fetched the first element out of the returned resultset, pushed new message to the element and called save on it and it started working.
Here is the code:
function saveUpdatesForNewChat(updates) {
return function(entity) {
var temp = entity[0];
temp.messages.push(updates);
var updated = temp;
return updated.saveAsync()
.spread(updated => {
return updated;
});
};
}