Mongoose one-to-many not working (Nodejs) - node.js

Question

I have created 2 Users(Admin and Users) and also i have created many ToDos for a User but here my Todo array is empty in my User Schema. Unable to understand why todo task are not assigned to the User Schema.
UserSchema
var userSchema = new Schema({
name: {
type: String,
required: true,
maxlength: 30,
trim: true
},
role: {
type: Number,
default: 0
},
todos: [{
type: Schema.Types.ObjectId,
ref:"Todo"
}]
});
module.exports = mongoose.model("User", userSchema)
Todo Schema
let Todo = new Schema({
todo_heading: {
type: String
},
todo_desc: {
type: String
},
todo_priority: {
type: String
},
todo_completed: {
type: Boolean
},
user: {
type: Schema.Types.ObjectId,
ref:"User"
}
})
module.exports = mongoose.model('Todo', Todo);
here are my routes
User Route
router.get("/user/:userId/todos", isSignedIn, isAuthenticated, getToDos)
Todo Route
router.get("/", getTodos)
router.get("/:id", getUsertodos);
router.post("/user/:userId/add", addUsertodos);
User Controllers
exports.getToDos = (req, res) => {
User.find({ _id: req.params._id })
.populate("todos")
.exec((err, toDo) => {
if (err) {
res.json(err)
}
res.json(toDo)
})
}
ToDo Controllers
exports.addUsertodos = (req, res) => {
let todo = new Todo(req.body)
todo.save((err, todo) => {
if (err) {
return res.status(400).json({
error: "not saved"
})
}
else {
return res.json(todo)
}
})
}

Answer 1

it should work as expected if you add the objectId of newly created todo to the todos property when you create a user.
//routers/todo.js
var express = require('express');
var router = express.Router();
const Todo = require('../models/Todo');
const User = require('../models/User');
/* GET home page. */
router.get('/', async function (req, res) {
let todos = await Todo.find();
res.json({
todos
});
});
router.post('/todos', async function (req, res) {
//add todos
let {
todo_desc,
todo_heading,
todo_priority,
todo_completed
} = req.body;
try {
//NOTE: for simplicity assigning first user but you can grab it from the params
let user = await User.findOne();
let todo = await Todo.create({
todo_desc,
todo_completed,
todo_priority,
todo_heading,
user: user._id
})
res.json({
message: 'todo created successfully',
todo
});
} catch (err) {
return res.status(500).json({
message: 'Unable to create a todo',
err: JSON.stringify(err)
})
}
});
module.exports = router;
Here is the user route where post route get the string id of created ID and converts it to ObjectId(), assign it to the todos.
var express = require('express');
var router = express.Router();
let _ = require('lodash');
var mongoose = require('mongoose');
const User = require('../models/User');
/* GET users listing. */
router.post("/", async function (req, res) {
let {
name,
todos
} = req.body;
try {
let user = new User();
user.name = name;
let objectIds = todos.split(',').map(id => mongoose.Types.ObjectId(id));
user.todos.push(...objectIds)
await user.save()
console.log("user: ", JSON.stringify(user));
if (_.isEmpty(user)) {
res.status(500).json({
message: 'unable to create user'
})
}
res.json(user);
} catch (err) {
res.status(500).json({
message: 'unable to create user',
err: JSON.stringify(err)
})
}
});
router.get("/", async function (req, res) {
try {
let user = await User.find().populate('todos');
console.log("user: ", JSON.stringify(user));
if (_.isEmpty(user)) {
res.status(500).json({
message: 'unable to find user'
})
}
res.json(user);
} catch (err) {
res.status(500).json({
message: 'unable to find user',
err: JSON.stringify(err)
})
}
});
module.exports = router;
Check out the attached screenshot, the user record now contains the todos assigned to it.
If you want checkout the working code, please visit this repo that i created!!.
Hope this help.Cheers!!