Using reference in Mongoose with ExpressJS - express

Question

Since I've noticed that deep nesting arrays in documents is not good practice, I wanted to use references in Mongoose using ExpressJS. Now I am making a CMS where there are menu items which the user can post. Each menu item can have sub items that the user can also post. But I don't know how to use referencing so I can reference between the main items collection and the sub items collection.
This is my Main_items Mongoose model:
var menuItems = new mongoose.Schema({
title : String,
subitem: {
type: mongoose.Types.ObjectId,
ref: 'sub_items'
}
}, {collection: 'menu_items'});
module.exports = mongoose.model("menu_items", menuItems);
And the sub_items model:
var subItems = new mongoose.Schema({
title: String,
});
module.exports = mongoose.model("sub_items", subItems);
Post of main_menu items
postController.postMainItems = function(req,res,item){
var saveData = {
title : req.body.title
};
var data = new item(saveData);
saveToDB(data,res);
};
I already created a post for the main menu items. That works. But now I want to know how I can post the sub items so they are directly referenced to each main item

Answer 1

Change the Schema as below, So that you need to insert the main menu first with title and then sub menu with title and parent(_id of parent main menu).
Main Menu Schema:
var menuItems = new mongoose.Schema({
title : String
}, {collection: 'menu_items'});
module.exports = mongoose.model("menu_items", menuItems);
Sub Menu Schema:
var subItems = new mongoose.Schema({
title: String,
parent: { type: mongoose.Types.ObjectId, ref: 'menu_items'}
});
module.exports = mongoose.model("sub_items", subItems);