How to save userId in mongoose hook? - node.js

Question

Given yon schema, how do I save userId to createdBy and updatedBy?
This seems like it should be an easy use case. How do I do it?
I'm not sure how to get userId from req.user.id to the model before being written.
// graph.model.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var schema = new Schema({
title: String,
createdAt: Date,
createdBy: String,
updatedAt: Date,
updatedBy: String,
});
// This could be anything
schema.pre('save', function (next) {
- if (!this.createdAt) {
this.createdAt = this.updatedAt = new Date;
this.createdBy = this.updatedBy = userId;
} else if (this.isModified()) {
this.updatedAt = new Date;
this.updatedBy = userId;
}
next();
});
Here's the controller code if you're interested:
var Graph = require('./graph.model');
// Creates a new Graph in the DB.
exports.create = function(req, res) {
Graph.create(req.body, function(err, thing) {
if(err) { return handleError(res, err); }
return res.status(201).json(thing);
});
};
// Updates an existing thing in the DB.
exports.update = function(req, res) {
if(req.body._id) { delete req.body._id; }
Graph.findById(req.params.id, function (err, thing) {
if (err) { return handleError(res, err); }
if(!thing) { return res.send(404); }
var updated = _.merge(thing, req.body);
updated.save(function (err) {
if (err) { return handleError(res, err); }
return res.json(thing);
});
});
};

Answer 1

The following is just another way of saving userId.
Sample model with createdBy, updatedBy, createdAt, updatedAt fields:
import mongoose from 'mongoose';
const SupplierSchema = new mongoose.Schema(
{
name: {
type: String,
},
createdBy: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
},
updatedBy: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
},
},
{
timestamps: {
createdAt: true,
updatedAt: true,
},
},
);
export default mongoose.model('Supplier', SupplierSchema);
Note that in mongoose starting from version ^4.13.17 you can simply specify timestamps createdAt, updatedAt directly in the schema.
https://mongoosejs.com/docs/4.x/docs/guide.html#timestamps
Then in supplier controller assign req.user._id to the fields createdBy, updatedBy:
import mongoose from 'mongoose';
import { Supplier } from '../models';
exports.create = async (req, res) => {
const supplierToCreate = new Supplier({
_id: new mongoose.Types.ObjectId(),
name: req.body.name,
createdBy: req.user._id,
updatedBy: req.user._id,
});
return supplierToCreate
.save()
.then(() =>
res.status(201).json({
message: 'New supplier is created successfully.',
}),
)
.catch(errSaving => res.status(500).json({ error: errSaving }));
};

Answer 2

You can't access req object inside of mongoose hook.
I think, you should define virtual field with a smart setter instead:
schema.virtual('modifiedBy').set(function (userId) {
if (this.isNew()) {
this.createdAt = this.updatedAt = new Date;
this.createdBy = this.updatedBy = userId;
} else {
this.updatedAt = new Date;
this.updatedBy = userId;
}
});
Now all you have to do is to set modifiedBy field with correct userId value in your controller:
var updated = _.merge(thing, req.body, {
modifiedBy: req.user.id
});