MongoDB, NodeJS: updating an embedded document with new members - json

Question

Using: MongoDB and native nodeJS mongoDB driver.
I'm trying to parse all the data from fb graph api, send it to my API and then save it to my DB.
PUT handling in my server:
//Update user's data
app.put('/api/users/:fbuser_id/:category', function(req, res) {
var body = JSON.stringify(req.body);
var rep = /"data":/;
body = body.replace(rep, '"' + req.params.category + '"' + ':');
req.body = JSON.parse(body);
db.fbusers.update({
id: req.params.fbuser_id
}, {
$set: req.body
}, {
safe: true,
multi: false
},
function(e, result) {
if (e) return next(e)
res.send((result === 1) ? {
msg: 'success'
} : {
msg: 'error'
})
});
});
I'm sending 25 elements at a time, and this code just overrides instead of updating the document.
Data I'm sending to the API:
{
"data": [
{
"category": "App page",
"name": "SoundCloud",
"id": "7919071058",
"created_time": "2013-09-16T18:16:59+0000"
},
{
...and so on
}
]
}
Basically my API changes "data" key from sent json to the category name, f.e.:
PUT to /api/users/000/likes will change the "data" key to "likes":
{
"likes": [
{
"category": "App page",
"name": "SoundCloud",
"id": "7919071058",
"created_time": "2013-09-16T18:16:59+0000"
},
{
...and so on
}
]
}
Then this JSON is put to the db.
Hierarchy in mongodb:
{
"_id": ObjectID("556584c8e908f0042836edce"),
"id": "0000000000000",
"email": "XXXX#gmail.com",
"first_name": "XXXXXXXX",
"gender": "male",
"last_name": "XXXXXXXXXX",
"link": "https://www.facebook.com/app_scoped_user_id/0000000000000/",
"locale": "en_US",
"name": "XXXXXXXXXX XXXXXXXXXX",
"timezone": 3,
"updated_time": "2015-05-26T18:11:59+0000",
"verified": true,
"likes": [
{
"category": "App page",
"name": "SoundCloud",
"id": "7919071058",
"created_time": "2013-09-16T18:16:59+0000"
},
{
"category": "App page",
"name": "SoundCloud",
"id": "7919071058",
"created_time": "2013-09-16T18:16:59+0000"
},
{
....and so on
}
]
}
So the problem is that my api overrides the field (in this case "likes") with newly sent data, instead of appending it to already existing data document.
I am pretty sure that I should be using other parameter than "$put" in the update, however, I have no idea which one and how to pass parameters to it programatically.

Answer 1

Use $push with the $each modifier to append multiple values to the array field.
var newLikes = [
{/* new item here */},
{/* new item here */},
{/* new item here */},
];
db.fbusers.update(
{ _id: req.params.fbuser_id },
{ $push: { likes: { $each: newLikes } } }
);
See also the $addToSet operator, it adds a value to an array unless the value is already present, in which case $addToSet does nothing to that array.