Mongoose - pushing refs - cannot read property "push" of undefined

Question

I would like to add a category and then if successed, push it's ref to user' collection. That's how I'm doing this:

That's mine "dashboard.js" file which contains categories schema.

var users = require('./users');

var category = mongoose.model('categories', new mongoose.Schema({
    _id:     String,
    name:    String,
    ownerId: { type: String, ref: 'users' }
}));

router.post('/settings/addCategory', function(req, res, next) {
  console.log(req.body);
  var category_toAdd = new category();
  category_toAdd._id = mongoose.Types.ObjectId();
  category_toAdd.name = req.body.categoryName;
  category_toAdd.ownerId = req.body.ownerId;

  category.findOne({
    name: req.body.categoryName,
    ownerId: req.body.ownerId
  }, function(error, result) {
     if(error) console.log(error);
     else {
       if(result === null) {
         category_toAdd.save(function(error) {
           if(error) console.log(error);
           else {
             console.log("Added category: " + category_toAdd);
<<<<<<<<<<<<<<<<<<<THE CONSOLE LOG WORKS GOOD
             users.categories.push(category_toAdd);
           }
         });
       }
     }
  });

Here is my "users.js" file which contains "users" schema.

var categories = require('./dashboard');

var user = mongoose.model('users', new mongoose.Schema({
    _id:          String,
    login:        String,
    password:     String,
    email:        String,
    categories:   [{ type: String, ref: 'categories' }]
}));

So, the category add proccess works well and I can find the category in database. The problem is when I'm trying to push the category to user.

This line:

users.categories.push(category_toAdd);

I get this error:

Cannot read property "push" of undefined.

I need to admit once more that before that pushing there is console.log where the category is printed properly.

Thanks for your time.

Answer 1

The users object is a Mongoose model and not an instance of it. You need the correct instance of the users model to add the category to.

dashboard.js

...
category_toAdd = {
  _id: mongoose.Types.ObjectId(),
  name: req.body.categoryName,
  ownerId: req.body.ownerId
};

// Create the category here. `category` is the saved category.
category.create(category_toAdd, function (err, category) {
  if (err) console.log(err);

  // Find the `user` that owns the category.
  users.findOne(category.ownerId, function (err, user) {
    if (err) console.log(err);

    // Add the category to the user's `categories` array.
    user.categories.push(category);
  });
});