validation of request parameters in nodejs against database fields

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.

Jitendra Khatri · Accepted Answer · 2016-05-27 06:32:29Z

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

answered May 27, 2016 at 6:32

Jitendra Khatri

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3 Comments

Rayees Over a year ago

i know middlewares are to defined but how

Jitendra Khatri Over a year ago

Have you tried the above code with specified note ?

Rayees Over a year ago

i just need answer to some_function_to_validate(req) req with json how shall i do that

Shrabanee · Accepted Answer · 2016-05-27 06:40:19Z

0

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
      }
};

answered May 27, 2016 at 6:40

Shrabanee

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1 Comment

Rayees Over a year ago

why shall i run loop; there must be other optimized way

ccw1078 · Accepted Answer · 2019-12-20 02:50:28Z

0

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));
});

edited Dec 20, 2019 at 2:50

answered Dec 20, 2019 at 1:13

ccw1078

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1 Comment

Akber Iqbal Over a year ago

on top of the reference to the article, can you share code of how it will help solve the questioner's problem... that will make it a high quality answer

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