validation of request parameters in nodejs against database fields - node.js

Question

I am building REST API using node, express and MongoDB(using mongoose) i want to add validation to post requests how can I do that I have defined schema like this
var CategorySchema = new Schema({
name: {
type: String,
lowercase: true,
default: '',
trim: true,
unique: [true, 'Category name already exists'],
required: [true, 'Category Name cannot be blank'],
minlength: [4, 'Minimum 4 characters required'],
maxlength: [20, 'Category name cannot be That long']
},
parentCategory: {
type: String,
lowercase: true,
default: '',
trim: true
},
description: {
type: String,
lowercase: true,
default: '',
trim: true,
required: [true, 'description cannot be blank'],
minlength: [10, 'Very short description']
},
slug: {
type: String,
lowercase: true,
unique: [true, 'Slug must be unique'],
required: true,
minlength: [4, "Minimum 4 Charater required"],
maxlength: [20, "Slug cannot be that long"]
},
imageUrl: {
type: String,
default: '',
trim: true
},
created: {
type: Date,
default: Date.now
},
updated: {
type: Date
}
});
module.exports = mongoose.model('Category', CategorySchema);
i am insert data using mongoose models like this
exports.createCategory = function (request, response) {
var newCategory = {
"name": request.body.categoryName,
"parentCategory": request.body.parentCategory,
"description": request.body.description,
"slug": request.body.slug,
"imageUrl": request.body.categoryImage,
"updated": new Date()
}
var category = new Category(newCategory);
category.save()
.then(function (category) {
sendResponse(response, 201, "success", category);
})
.catch(function (error) {
sendResponse(response, 400, "error", error);
});
};
but I want to add validation to the post request. I have to make sure that fields that are defined in a database are there in a request and values must be required as well I am really confused how to validate key in a JSON object inside request body. I have already added some validation using mongoose.

Answer 1

You can use Middlewares for this purpose like (If you are using express framework) :
app.use(function (req, res, next) {
var validationErrors = [];
validationErrors = some_function_to_validate(req); // Returns array
if(validationErrors.length > 0) {
// Send Custom Response with Validation Error
}
else {
next();
}
});
Note : This middleware will be executed for all of your requests (If added before all the routes registration).
For more please refer : http://expressjs.com/en/guide/using-middleware.html

Answer 2

Try following code to get the valid fields. It will return false if any field i.e. not required is coming with the req. Hope this will help.
function validateReq(req)
{
if(req)
{
var prop = ['name','parentCategory','description'] //Add more property name here
var found = false;
for(var key in req.body)
{
if (prop[key] && (prop[key] !== null))
{
found = true;
}
else
{
return false;
}
}
}
else
{
return false;
}
}
exports.createCategory = function (request, response) {
var valid = validateReq(request);
alert(valid);
if(valid){
var newCategory = {
"name": request.body.categoryName,
"parentCategory": request.body.parentCategory,
"description": request.body.description,
"slug": request.body.slug,
"imageUrl": request.body.categoryImage,
"updated": new Date()
}
var category = new Category(newCategory);
category.save()
.then(function (category) {
sendResponse(response, 201, "success", category);
})
.catch(function (error) {
sendResponse(response, 400, "error", error);
});
}
else
{
//Error handling code
}
};

Answer 3

My answer seems to be too late, but hopefully it will help others in future. I think you can try express-validator, here is an article explains how to use it in detail.
Its basic idea is to add a middleware, and put all the validations inside, which can be invoked in subsequent route functions. This way can keep the business logic code clean.
below is an example from official docs
// ...rest of the initial code omitted for simplicity.
const { check, validationResult } = require('express-validator');
app.post('/user', [
// username must be an email
check('username').isEmail(),
// password must be at least 5 chars long
check('password').isLength({ min: 5 })
], (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(422).json({ errors: errors.array() });
}
User.create({
username: req.body.username,
password: req.body.password
}).then(user => res.json(user));
});