Nodejs/Mongoose pass a variable to mongoose function

Question

I am new to Node.js and Mongoose and need some help. So I first create an array called beerObjects. Then I make a request to breweryDB and store info in this array.

request(options, function (error, response, body) {
            if (error) throw new Error(error);
            obj = JSON.parse(body);
            data = obj['data'];
            for(i = 0; i < data.length; i++) {
                var newBeer = new Beer();
                newBeer.id = data[i]['id'];
                newBeer.name = data[i]['name'];
                newBeer.description = data[i]['description'];
                newBeer.abv = data[i]['abv'];
                if (data[i].hasOwnProperty('labels')) {
                    newBeer.image = data[i]['labels']['large'];
                }

                beerObjects.push(newBeer);
                console.log(beerObjects[i].name);
            }
            addBeersToDatabase(beerObjects);
        });

I have another function that will take this array and store the info in my mongo database.

function addBeersToDatabase(beerObjects) {
console.log(beerObjects.length);
for (i = 0; i < beerObjects.length; i++) {
    console.log(beerObjects[i].id);
    // check if beer is already in database
    Beer.count({id: beerObjects[i].id}, function(err, count){
        if (err) {
            handleError(err);
        }
        if (count == 0) {
            // add new beer to database
            var newBeer = new Beer();
            newBeer.id = beerObjects[i].id;
            newBeer.name = beerObjects[i].name;
            newBeer.description = beerObjects[i].description;
            newBeer.abv = beerObjects[i].abv;
            newBeer.image = beerObjects[i].image;

            newBeer.save(function(err) {
                if (err) {
                    throw err;
                }
            });

        }
        else {
            // beer is already in database
        }
    });
}

}

In the beginning of the addBeerToDatabase() function, beerObject is defined and the console.log() statements output the correct information. But inside the Mongoose function Beer.count(), I get this error message.

newBeer.id = beerObjects[i].id;
TypeError: Cannot read property 'id' of undefined

This 'id' is the id of beerObjects[i], not newBeer. How do I correctly pass beerObjects to the mongoose function and use it in that function?

EDIT:

function addBeersToDatabase(beerObjects) {
for (i = 0; i < beerObjects.length; i++) {
    console.log(beerObjects[i].beerId);
    var currentBeer = beerObjects[i];

    // check if beer is already in database
    Beer.findOne({'beerId': currentBeer.beerId}, function(err, beer){
        if (err) {
            handleError(err);
        }
        if (beer) {
            // beer is already in database
        }
        else {
            // add new beer to database
            console.log(currentBeer.name);
            saveNewBeer(currentBeer);
        }
    });
}

}

function saveNewBeer(currentBeer) {
var newBeer = new Beer();
newBeer.beerId = currentBeer.beerId;
newBeer.name = currentBeer.name;
newBeer.description = currentBeer.description;
newBeer.abv = currentBeer.abv;
newBeer.image = currentBeer.image;

newBeer.save(function(err) {
    if (err) {
        throw err;
    }
});

}

This code is adding n duplicates (where n = beerObjects.length) of just the last item in beerObjects.

Answer 1

MongoDB ID is auto-generated so you cannot added any values into _id property unless you defined _id as String in your mongoose model.

For example.

var mongoose = require('mongoose');
var beerSchema = new mongoose.Schema({
    _id: String,
    name: String,
    // rest of beer properties
});

module.exports = mongoose.model('Beer', beerSchema);

Inside your function,

function addBeersToDatabase(beerObjects) {
    for (i = 0; i < beerObjects.length; i++) {
    Beer.findbyId(beerObjects[i].id, function(err, beers){
        if (beers.lenght == 0) {
            // add new beer to database
            var newBeer = new Beer();
            newBeer._id = beerObjects[i].id;
            newBeer.name = beerObjects[i].name;
            newBeer.description = beerObjects[i].description;
            newBeer.abv = beerObjects[i].abv;
            newBeer.image = beerObjects[i].image;
            newBeer.save();
        }
        else {
            // beer is already in database
        }
    });
}

If you want to use default mongoId, you just need to remove _id: String in model and newBeer._id = beerObjects[i]id from your function. I hope this would help you.

Answer 2

Edit:

You are looping through and 'grabbing' a beer with beerObject[i].id, then you asynchronously check the count, by the time you get down to setting newBeer.id you are in a different scope. The remedy to this is to set a variable to beerObject[i].id and pass that in as the 'beer' you look for in the Beer.count:

like so:

for (i = 0; i < beerObjects.length; i++) {
    console.log(beerObjects[i].id);
    var checkBeer = beerObjects[i]
    // check if beer is already in database
    Beer.count({id: checkBeer.id}, function(err, count){
        if (err) {
            handleError(err);
        }
        if (count == 0) {
            // add new beer to database
            var newBeer = new Beer();
            newBeer.id = checkBeer.id;
... and so on

Answer 3

You need to use _id instead of id :

newBeer._id = data[i]['id'];
newBeer.name = data[i]['name'];