Nodejs findOneAndUpdate paramerters - node.js

Question

I have a user model with the following schema, all fields required
name:String,
country:String,
age:Number
From frontend i press update button and update only the age field, and on backend i have the following
var body = _.pick(req.body, ["candidateId","name","age","country"]);
var candidateId = mongoose.Types.ObjectId(body.candidateId);
Candidate.findOneAndUpdate({
_id:candidateId
},{
name: body.name,
country: body.country,
age: body.age,
}).then((data) => {
if (!data) {
res.status(400).send('noDataFound');
} else {
res.status(200).send(data);
}
}).catch((e) => {
res.status(500).send(e)
})
Front passes the data as follows
{ "candidateId":"5a9a86c16acff45a8070d2da",
"name":"Superman",
}
I will get get undefined error for body.age and body.country since its not passed from front end.
QUESTION - How can use the previous values if no value is send from front end for some parameter, one approach is to send everything even if its not changed.

Answer 1

It looks like you're using lodash, check out omitBy to remove undefined or null properties:
_.omitBy({ foo: 'foo', bar: undefined, baz: null }, _.isNil)
{foo: "foo"}
Here's a vanilla JS solution:
Object
.entries({ foo: 'foo', bar: undefined, baz: null })
.filter(([_, value]) => value !== null && value !== undefined)
.reduce((acc, [key, value]) => { acc[key] = value; return acc; }, {})

Answer 2

When I'm facing this problem I usually create a parser function as:
var body = _.pick(req.body, ["candidateId","name","age","country"]);
var candidateId = mongoose.Types.ObjectId(body.candidateId);
function createUpdatedValues(params) {
var condition = {};
if (params.candidateId) condition.candidateId = params.candidateId;
if (params.name) condition.name = params.name;
if (params.age) condition.age = params.age;
if (params.country) condition.country = params.country;
return condition;
}
Candidate.findOneAndUpdate({
_id:candidateId
},createUpdatedValues(body)).then((data) => {
if (!data) {
res.status(400).send('noDataFound');
} else {
res.status(200).send(data);
}
}).catch((e) => {
res.status(500).send(e)
})

Answer 3

Form a new object that includes sent values:
const newObj = {};
if (body.name) {
newObj.name = body.name;
}
if (body.age) {
newObj.age = body.age;
}
if (body.country) {
newObj.country = body.country;
}
Then update using newObj.
Candidate.findOneAndUpdate({
_id:candidateId
}, newObj)...

Answer 4

I am using the following way to go around it , if any other better approach is there let me know ill mark that as answer.
I am now passing all the data to update from frontend in a new object like this
--- Client Data---
{ "candidateId":"5a9a86c16acff45a8070d2da",
"updatedData":{
"firstName":"Jack",
"lastName":"Bauer",
"applicationSource":"consultant",
"skills":["trading","sales"]
}
}
---- Updating logic ----
var body = _.pick(req.body, ["candidateId","updatedData"]);
var candidateId = mongoose.Types.ObjectId(body.candidateId);
var dataToUpdate = _.pick(body.updatedData,["firstName","lastName"]);
Candidate.findOneAndUpdate({
_id:candidateId
},dataToUpdate).then((data) => {
if (!data) {
res.status(400).send('noDataFound');
} else {
res.status(200).send(data);
}
}).catch((e) => {
res.status(500).send(e)
})