I have been diving into MongoDB through their online Webinar hosted on their platform and I am currently working on connecting Products to a Category (for example, associating iPhones with the Mobiles Category which falls under Electronics). However, as I attempt to nest them, I encounter the following error:
MongooseError: Schema hasn't been registered for model "Category".
Use mongoose.model(name, schema)
I have come across suggestions such as using Schema.ObjectId and Schema.Types.ObjectId, yet I still face a Cast Error to ObjectId when executing an insert(save) query.
There are some additional queries that arise in relation to this matter:
- How can I ensure that when adding a Product, the associated Category is also added?
- What would be the best approach for handling this situation (adding subdocuments or reference Schemas)?
Below are snippets from the Model files, followed by the Controller files I have developed to carry out CRUD operations:
category.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var categorySchema = new Schema({
_id: { type: String },
parent: {
type: String,
ref: 'Category'
},
ancestors: [{
type: String,
ref: 'Category'
}]
});
module.exports.categorySchema = categorySchema;
products.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var Category = require('./category');
var fx = require('./fx');
var productSchema = new mongoose.Schema({
name: { type: String, required: true },
// Pictures must start with "http://"
pictures: [{ type: String, match: /^http:\/\//i }],
price: {
amount: {
type: Number,
required: true,
set: function(v) {
this.internal.approximatePriceUSD =
v / (fx()[this.price.currency] || 1);
return v;
}
},
// Only 3 supported currencies for now
currency: {
type: String,
enum: ['USD', 'EUR', 'GBP'],
required: true,
set: function(v) {
this.internal.approximatePriceUSD =
this.price.amount / (fx()[v] || 1);
return v;
}
}
},
category: { type: Schema.ObjectId,ref: 'Category'},
internal: {
approximatePriceUSD: Number
}
});
//var schema = new mongoose.Schema(productSchema);
var currencySymbols = {
'USD': '$',
'EUR': '€',
'GBP': '£'
};
/*
* Human-readable string form of price - "$25" rather
* than "25 USD"
*/
productSchema.virtual('displayPrice').get(function() {
return currencySymbols[this.price.currency] +
'' + this.price.amount;
});
productSchema.set('toObject', { virtuals: true });
productSchema.set('toJSON', { virtuals: true });
module.exports = mongoose.model("Product", productSchema);
Illustrative Output Structure of a Product:
{
"_id": "**autogeneratedByMongo",
"name":"iPhone",
"category":{
"_id":"Mobiles",
"ancestors":["Electronics","Mobiles"]
}
....
}