How can you render items only if matching category? - node.js

Question

I'm trying to build an ecommerce shop using express and mongodb. I'm trying to make categories for the shop. (e.g when someone clicks a category it should only display the items corresponding to that category) I've tried multiple ways to tackle this issue but haven't found a solution.
My current code is this one:
var NFTitem = require("../models/NFTitem")
var Item = require('../models/item');
var async = require('async')
exports.item_list = function(req, res, next) {
async.parallel({
item: function(callback) {
Item.find({}).exec(callback);
},
collection_list: function (callback) {
NFTitem.find({}).exec(callback);
},
collection: function(callback) {
NFTitem.find({'_id' : req.params.id }).exec(callback)
},
thisCategory: function (callback) {
Item.find({'collectionItem' : req.params.id }).exec(callback);
},
}, function(err, results) {
res.render('item_list.jade', { title: "NFT Marketplace", collection_list: results.item});
})
}
Now the logic behind this is to find the items corresponding to the items database which is (Item) and extract it, finding only the id matching the categories database. Then we would find the id for the categories database which is (NFTitem). Then we would do and if else command so that it only shows if both ids are matching. But this method doesn't seem to work.
I've also tried filtering the thing but it displays nothing when i filter it out. I would like to know what would be the best solution for this and if there's any way I could solve this issue.
rendered website:
block content
h1= title
ul
each collection in collection_list
li
a(href=collection.url) #{collection.name}
models for items:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var ItemSchema = new Schema(
{
name: {type: String, required: true},
description: {type: String, required: true},
collectionItem: {type: Schema.Types.ObjectId, ref: 'nftitem', required: true},
price: {type: Number, required: true},
instock: {type: Number, required: true},
}
);
// Virtual for book's URL
ItemSchema
.virtual('url')
.get(function () {
return '/catalog/item/' + this._id;
});
//Export model
module.exports = mongoose.model('Item', ItemSchema);
models for collections:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var NFTItemSchema = new Schema(
{
name: {type: String, required: true},
description: {type: String, required: true},
}
);
// Virtual for book's URL
NFTItemSchema
.virtual('url')
.get(function () {
return '/catalog/nftitem/' + this.name;
});
//Export model
module.exports = mongoose.model('nftitem', NFTItemSchema);

Answer 1

Since the collectionItem field in Item Schema is a reference to NFTItemSchema Schema, you can query Item Collection directly. You can refactor and simplify your code like this:
const Item = require('../models/item');
exports.item_list = async (req, res, next) => {
try{
let all_items = await Item.find({collectionItem: req.params.id});
res.render('item_list.jade', { title: "NFT Marketplace", collection_list: all_items });
} catch (error) {
res.status(400).json(error: error);
}
}