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Validr

Framework agnostic Node.js validations. Inspired by validator, express-validator and validictorian.

Installation

npm install validr

Usage

If you have ever used express-validator you should feel right at home.

Here is an example using Express. Can be used similarly in any other framework.

var express = require('express'),
  Validr = require('validr'),
  trimBody = require('trim-body');

app = express();

app.use(express.bodyParser());
app.use(app.router);

app.post('/user', function (req, res){
  trimBody(req.body);

  // Expected 'req.body' object format
  // {
  //   name: {
  //     first: <first name>,
  //     last: <last name>
  //   },
  //   email: <email>,
  //   age: <age>,
  //   sex: <sex>,
  //   occupation: <occupation>
  // }


  // 1. Create an instance of Validr.

  var validr = new Validr(req.body);


  // 2. Validations

  validr
    // use string with dot-notation to validate nested fields
    .validate('name.first', 'First Name is required.')
    .isLength(1);

  validr
    // you can also use an array to validate nested fields
    .validate(['name', 'last'], 'Last Name is required.')
    .isLength(1);

  validr
    // an object can be used to set separate validation messages for validators.
    .validate('email', {
      isLength: 'Email is required.',
      isEmail: 'Email must be valid.'
    })
    // validators are chainable
    .isLength(1).isEmail(); 

  validr
    // validate method accepts a 3rd parameter which is an options object
    // age will not be validated if '', `null` or undefined
    .validate('age', 'Age must be a number.', {ignoreEmpty: true})
    .isNumeric();

  validr
    .validate('sex', 'Sex must be M (male) or F (female).')
    .isIn(['M', 'F']).isLength(1);


  // 3. Check for errors.

  var errors = validr.validationErrors();

  if (errors) return res.json(errors);



  // ...
  // Process req.body however you want. Example: save to db.
});


app.listen(3000);

Validate

Validating fields is similar to express-validator's assert.

Differences between validate and assert.

No notEmpty and len methods. Use isLength.
Nested fields are targeted with a dot-notation string or array. Example: 'name.first' or ['name', 'first'].

You can pass a 3rd parameter to validate to ignore validation if field is not supplied. See usage's age validation

Validation errors

You can get errors in two ways. Similar to express-validator.

var errors = validr.validationErrors();
var mappedErrors = validr.validationErrors(true);

errors:

[
  {param: "email", msg: "Email is required.", value: "<received input>"},
  {param: "email", msg: "Email must be valid.", value: "<received input>"},
  {param: "age", msg: "Age must be a number.", value: "<received input>"}
]

mappedErrors:

{
  email: {
    param: "email",
    msg: "Email must be valid.",
    value: "<received input>"
  },
  age: {
    param: "age",
    msg: "Age is required.",
    value: "<received input>"
  }
}

Extending with custom validators

Add custom validator functions to an object, which is the second parameter when instantiating Validr.

var validr = new Validr(body, {
  isNotExampleEmail: function(str) {
    return !/@example.com/.test(str);
  }
});

validr.validate('email', {
  isLength: 'Email is required.',
  isEmail: 'Email must be valid',
  isNotExampleEmail: 'Email must NOT be @example.com.'
  }).isLength(1).isEmail().isNotExampleEmail();