Mongoose/Mongo: Update Not Saving - arrays

Question

I'm extremely perplexed by this issue that I'm having with mongo/mongoose. I'm essentially trying to get an array of products, delete a certain product from the array, and then update the shopping chart with the new array that omits the selected product. Here's the snippet of code I'm dealing with:
const remove = (req, res, next) => {
console.log('here is the product id ' + req.body.cart.product)
delete req.body._owner // disallow owner reassignment.
Cart.find({_id: req.user.cartId})
.then((products1) => {
console.log("array of products: " + products1[0].product)
const index = products1[0].product.indexOf(req.body.cart.product)
console.log("index valeu: " + index)
if (index > -1) {
products1[0].product.splice(index, 1)
return products1[0].product
}
return products1[0].product
})
.then((products2) => {
console.log('Second Promise Input: ' + products2)
Cart.update({_id: req.user.cartId}, {$set: {product: products2}})
})
.then(() => res.sendStatus(204))
.catch(next)
}
And here's the output from my server:
Server listening on port 4741
here is the product id 5952b57ea52d092b8d34c6b0
array of products: 5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0
index valeu: 0
Second Promise Input: 5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0,5952b57ea52d092b8d34c6b0
PATCH /carts-decrease/595b037e128cfd37e0c864d7 204 38.773 ms
According to my console.logs, I'm getting the array just the way I want it but it simply does not update the shopping cart with the new array. I've been staring at this code for far too long and I'd appreciate a second set of eyes on this. Thanks.
P.S. Ignore the fact that the product ids are all the same, its just a testing variable
Cart Schema:
'use strict'
const mongoose = require('mongoose')
const cartSchema = new mongoose.Schema({
product: {
type: Array,
required: false
},
owner: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
required: false
}
}, {
timestamps: true,
toJSON: {
virtuals: true,
transform: function (doc, ret, options) {
const userId = (options.user && options.user._id) || false
ret.editable = userId && userId.equals(doc._owner)
return ret
}
}
})
const Cart = mongoose.model('Cart', cartSchema)
module.exports = Cart
Product Schema:
'use strict'
const mongoose = require('mongoose')
const productSchema = new mongoose.Schema({
name: {
type: String,
required: true
},
price: {
type: Number,
required: true
},
description: {
type: String,
required: true
}
}, {
toJSON: {
virtuals: true
}
})
const Product = mongoose.model('Product', productSchema)
module.exports = Product
Show request:
const show = (req, res) => {
const product = {}
product.array = []
// console.log(req.cart.product)
const promises = []
Promise.all(req.cart.product.map(function (id) {
return Product.find({_id: ObjectId(id)})
})).then(function (products) {
console.log(products)
req.cart.product = products
return res.json({
cart: req.cart.toJSON({virtuals: true, user: req.user})
})
}).catch(function (err) {
console.log(err)
return res.sendStatus(500)
})
}

Answer 1

I would recommend you to slightly modify your cartSchema and store products in the form of an array of embedded documents:
const cartSchema = new mongoose.Schema({
products: [{
name: { type: String },
price: { type: Number }
...
}]
...
});
If you do this you can simply use the $pull update operator to remove products from your cart:
{ $pull: { <field1>: <value|condition>, <field2>: <value|condition>, ... } }
In your case the query should then look like this:
Cart.update(
{ _id: req.user.cartId },
{ $pull: { products: { '_id': req.body.cart.product } }}
);
As the embedded documents will have their own ObjectId there will only be one document matching the query.