The validator.js library makes data validation in JavaScript very easy in both the browser and Node.js.
npm install @chantouchsek/validatorjs





The ValidatorJs library makes data validation in JavaScript very easy in both the browser and Node.js. This library was
forked from ValidatorJs to re-write in typescript to add more rules and
features.
- Works in both the browser and Node.
- Readable and declarative validation rules.
- Error messages with multilingual support.
- CommonJS/Browserify support.
- ES6 support.
- Re-written in Typescript
``bash`
pnpm add @chantouchsek/validatorjs
`bash`
npm install @chantouchsek/validatorjs
`bash`
yarn add @chantouchsek/validatorjs
`js
import { Validator } from '@chantouchsek/validatorjs'
const validation = new Validator(data, rules, options)
`
data {Object} - The data you want to validate
rules {Object} - Validation rules
options {Object} - Optional custom options to return
- Options
- locale?: string | Optional passing locale from config
- confirmedReverse?: boolean | Optional showing error message on confirmation field instead of password
- customMessages?: Record
- customAttributes?: Record
- defaultAttributeName?: Record
#### Example 1 - Passing Validation
`js
const data = {
age: 28,
email: 'johndoe@gmail.com',
name: 'John',
}
const rules = {
age: 'min:18',
email: 'required|email',
name: 'required',
}
const validation = new Validator(data, rules)
validation.passes() // true
validation.fails() // false
`
To apply validation rules to the _data_ object, use the same object key names for the _rules_ object.
#### Example 2 - Failing Validation
`js
const validation = new Validator(
{
email: 'not an email address.com',
name: 'D',
},
{
email: 'required|email',
name: 'size:3',
},
)
validation.fails() // true
validation.passes() // false
// Error messages
validation.errors.first('email') // 'The email format is invalid.'
validation.errors.get('email') // returns an array of all email error messages
`
#### Example 3 - With Default Attribute Name
`ts
const validation = new Validator(
{
email: 'not an email address.com',
name: 'D',
},
{
email: 'required|email',
name: 'size:3',
},
{
defaultAttributeName: {
en: '',
ja: 'この項目',
},
}
)
validation.fails() // true
validation.passes() // false
// Error messages
validation.errors.first('email') // 'The field format is invalid.'
validation.errors.first('email') // 'この項目は正しいメールアドレスを入力してください。'
validation.errors.get('email') // returns an array of all email error messages
`
Nested objects can also be validated. There are two ways to declare validation rules for nested objects. The first way
is to declare the validation rules with a corresponding nested object structure that reflects the data. The second way
is to declare validation rules with flattened key names. For example, to validate the following data:
`js`
const data = {
bio: {
age: 28,
education: {
primary: 'Elementary School',
secondary: 'Secondary School',
},
},
name: 'John',
}
We could declare our validation rules as follows:
`js
const nested = {
bio: {
age: 'min:18',
education: {
primary: 'string',
secondary: 'string',
},
},
name: 'required',
}
// OR
const flattened = {
'bio.age': 'min:18',
'bio.education.primary': 'string',
'bio.education.secondary': 'string',
'name': 'required',
}
`
WildCards can also be validated.
`js`
const data = {
users: [
{
bio: {
age: 28,
education: {
primary: 'Elementary School',
secondary: 'Secondary School',
},
},
name: 'John',
},
],
}
We could declare our validation rules as follows:
`js`
const rules = {
'users.*.bio.age': 'min:18',
'users.*.bio.education.primary': 'string',
'users.*.bio.education.secondary': 'string',
'users.*.name': 'required',
}
Validation rules do not have an implicit 'required'. If a field is _undefined_ or an empty string, it will pass
validation. If you want a validation to fail for undefined or '', use the _required_ rule.
#### accepted
The field under validation must be yes, on, 1 or true. This is useful for validating "Terms of Service" acceptance.
#### after:date
The field under validation must be after the given date.
#### after_or_equal:date
The field under validation must be after or equal to the given field
#### alpha
The field under validation must be entirely alphabetic characters.
#### alpha_dash
The field under validation may have alphanumeric characters, as well as dashes and underscores.
#### alpha_num
The field under validation must be entirely alphanumeric characters.
#### array
The field under validation must be an array.
#### before:date
The field under validation must be before the given date.
#### before_or_equal:date
The field under validation must be before or equal to the given date.
#### between:min,max
The field under validation must have a size between the given min and max. Strings, numerics, and files are evaluated in
the same fashion as the size rule.
#### boolean
The field under validation must be a boolean value of the form true, false, 0, 1, 'true', 'false', '0''1'
, ,
#### confirmed
The field under validation must have a matching field of foo_confirmation. For example, if the field under validation is
password, a matching password_confirmation field must be present in the input.
#### date
The field under validation must be a valid date format which is acceptable by Javascript's Date object.
#### digits:value
The field under validation must be numeric and must have an exact length of value.
#### digits_between:min,max
The field under validation must be numeric and must have length between given min and max.
#### different:attribute
The given field must be different from the field under validation.
The field under validation must be formatted as an e-mail address.
#### hex
The field under validation should be a hexadecimal format. Useful in combination with other rules, like hex|size:6 for
hex color code validation.
#### in:foo,bar,...
The field under validation must be included in the given list of values. The field can be an array or string.
#### integer
The field under validation must have an integer value.
#### max:value
Validate that an attribute is no greater than a given size
_Note: Maximum checks are inclusive._
#### Example 1 - Max validation
`js`
const rules = {
phone: 'required|digits|max:11',
}
const input = {
phone: '01234567890',
}
// passes: true
#### Example 2 - Max validation
`js`
const rules = {
phone: 'integer|max:16',
}
const input = {
phone: '18',
}
// passes: false
#### min:value
Validate that an attribute is at least a given size.
_Note: Minimum checks are inclusive._
#### Example 1 - Min validation
`js`
const rules = {
phone: 'required|digits|min:11',
}
const input = {
phone: '01234567890',
}
// passes: true
#### Example 2 - Min validation
`js`
const rules = {
phone: 'integer|min:11',
}
const input = {
phone: '18',
}
// passes: false
#### not_in:foo,bar,...
The field under validation must not be included in the given list of values.
#### numeric
Validate that an attribute is numeric. The string representation of a number will pass.
`js`
const rules = {
amount: 'numeric|digits:5',
}
#### present
The field under validation must be present in the input data but can be empty.
#### required
Checks if the length of the String representation of the value is >
#### required_if:another_field,value
The field under validation must be present and not empty if the another field is equal to any value.
#### required_unless:another_field,value
The field under validation must be present and not empty unless the another field is equal to any value.
#### required_with:foo,bar,...
The field under validation must be present and not empty only if any of the other specified fields are present.
#### required_with_all:foo,bar,...
The field under validation must be present and not empty only if all the other specified fields are present.
#### required_without:foo,bar,...
The field under validation must be present and not empty only when any of the other specified fields are not present.
#### required_without_all:foo,bar,...
The field under validation must be present and not empty only when all the other specified fields are not present.
#### sometimes
In some situations, you may wish to run validation checks against a field only if that field is present in the data being validated. To quickly accomplish this, add the sometimes rule to your rule list:
`js`
const rules = {
email: 'sometimes|required|email',
}
In the example above, the email field will only be validated if it is present in the input.
#### same:attribute
The given field must match the field under validation.
#### size:value
The field under validation must have a size matching the given value. For string data, value corresponds to the number
of characters. For numeric data, value corresponds to a given integer value.
#### string
The field under validation must be a string.
#### url
Validate that an attribute has a valid URL format
#### regex:pattern
The field under validation must match the given regular expression.
Note: When using the regex pattern, it may be necessary to specify rules in an array instead of using pipe
delimiters, especially if the regular expression contains a pipe character. For each backward slash that you used in
your regex pattern, you must escape each one with another backward slash.
#### Example 3 - Regex validation
`js
const validation = new Validator(
{
name: 'Doe',
salary: '10,000.00',
yearOfBirth: '1980',
},
{
name: 'required|size:3',
salary: ['required', 'regex:/^(?!0\\.00)\\d{1,3}(,\\d{3})*(\\.\\d\\d)?$/'],
yearOfBirth: ['required', 'regex:/^(19|20)[\\d]{2,2}$/'],
},
)
validation.fails() // false
validation.passes() // true
`
#### Example 4 - Type Checking Validation
`js
const validation = new Validator(
{
age: 30,
name: '',
},
{
age: ['required', { in: [29, 30] }],
name: [{ required_if: ['age', 30] }],
},
)
validation.fails() // true
validation.passes() // false
`
`js`
Validator.register(name, callbackFn, errorMessage)
name {String} - The name of the rule.
callbackFn {Function} - Returns a boolean to represent a successful or failed validation.
errorMessage {String} - An optional string where you can specify a custom error message. _:attribute_ inside
errorMessage will be replaced with the attribute name.
`js`
Validator.register(
'telephone',
(value, requirement, attribute) => {
// requirement parameter defaults to null
return value.match(/^\d{3}-\d{3}-\d{4}$/)
},
'The :attribute phone number is not in the format XXX-XXX-XXXX.',
)
Register an asynchronous rule which accepts a passes callback:
`jspasses
Validator.registerAsync('username_available', (username, attribute, req, passes) => {
// do your database/api checks here etc
// then call the method where appropriate:`
passes() // if username is available
passes(false, 'Username has already been taken.') // if username is not available
})
Then call your validator using checkAsync passing fails and passes callbacks like so:
`js
const validator = new Validator(
{
username: 'test123',
},
{
username: 'required|min:3|username_available',
},
)
function passes() {
// Validation passed
}
function fails() {
validator.errors.first('username')
}
validator.checkAsync(passes, fails)
`
Use validated() method to retrieve only the validated data and to filter out attributes not found on rules provided.
`js{ "name": "John", "age": 28 }
const validation = new Validator(
{
age: 28,
email: 'johndoe@gmail.com',
gender: 'male',
name: 'John',
},
{
age: 'min:18',
name: 'required',
},
)
validation.validated() // will return `
validated() method will throw an error when current validation is failing.
`jsError('Validation failed!')
const validation = new Validator(
{
age: 28,
email: 'johndoe@gmail.com',
gender: 'male',
name: 'John',
},
{
age: 'min:40',
name: 'required',
},
)
validation.validated() // will throw `
validated() method also works with asynchronous validation. In this case,passes() callback will receive only the validated data (without the
attributes not found on rules provided) as the first argument.
`js{ "name": "John", "age": 28 }
const validation = new Validator(
{
age: 28,
email: 'johndoe@gmail.com',
gender: 'male',
name: 'John',
},
{
age: 'min:18',
name: 'required|some_async_rule',
},
)
function passes(validated) {
console.log(validated) // will output if some_async_rule validates 'John'some_async_rule
}
function fails() {
// will be called if does not validate 'John'`
}
validation.validated(passes, fails)
This constructor will automatically generate error messages for validation rules that failed.
If there are errors, the Validator instance will have its errors property object populated with the error messages
for all failing attributes. The methods and properties on the errors property object are:
#### .first(attribute)
returns the first error message for an attribute, false otherwise
#### .get(attribute)
returns an array of error messages for an attribute, or an empty array if there are no errors
#### .all()
returns an object containing all error messages for all failing attributes
#### .has(attribute)
returns true if error messages exist for an attribute, false otherwise
#### .errorCount
the number of validation errors
`js`
const validation = new Validator(input, rules)
validation.errors.first('email') // returns first error message for email attribute
validator.errors.get('email') // returns an array of error messages for the email attribute
If you need a specific error message, and you don't want to override the default one, you can pass an override as the
third argument to the Validator object, just like
with Laravel.
`js
const input = {
name: '',
}
const rules = {
name: 'required',
}
const validation = new Validator(input, rules, {
required: 'You forgot to give a :attribute',
})
validation.passes()
validation.errors.first('name') // returns 'You forgot to give a name'
`
Some validators have string and numeric versions. You can change them too.
`js
const input = {
username: 'myusernameistoolong',
}
const rules = {
username: 'max:16',
}
const validation = new Validator(input, rules, {
max: {
string: 'The :attribute is too long. Max length is :max.',
},
})
validation.passes()
validation.errors.first('username') // returns 'The username is too long. Max length is 16.'
`
You can even provide error messages on a per-attribute basis! Just set the message's key to 'validator.attribute'
`js
const input = { email: '', name: '' }
const rules = { email: 'required', name: 'required' }
const validation = new Validator(input, rules, {
'required.email': 'Without an :attribute we can\'t reach you!',
})
validation.passes()
validation.errors.first('name') // returns 'The name field is required.'
validation.errors.first('email') // returns 'Without an email we can\'t reach you!'
`
#### Using config for custom attribute name
`js`
const validator = new Validator(
{ form: { name: null } },
{ form: { age: 'required', name: 'required' } },
{
customAttributes: { form: { name: 'Username' } },
customMessages: {
required: 'The :attribute need to be filled.',
},
},
)
if (validator.fails())
validator.errors.first('form.name') // "The Userame need to be filled."
To display a custom "friendly" attribute name in error messages, use .setAttributeNames()
`js`
const validator = new Validator({ name: '' }, { name: 'required' })
validator.setAttributeNames({ name: 'custom_name' })
if (validator.fails())
validator.errors.first('name') // "The custom_name field is required."
Alternatively you can supply global custom attribute names in your lang with the attributes property.
You can also configure a custom attribute formatter:
`js
// Configure global formatter.
Validator.setAttributeFormatter((attribute) => {
return attribute.replace(/_/g, ' ')
})
// Or configure formatter for particular instance.
const validator = new Validator({ first_name: '' }, { first_name: 'required' })
validator.setAttributeFormatter((attribute) => {
return attribute.replace(/_/g, ' ')
})
if (validator.fails())
console.log(validator.errors.first('first_name')) // The first name field is required.
`
Note: by default all \_ characters will be replaced with spaces.
Error messages are in English by default. To include another language in the browser, reference the language file in a
script tag and call Validator.useLang('lang_code').
`html`
In Node, it will automatically pick up on the language source files.
`js
const Validator = require('validatorjs')
Validator.useLang('km')
`
If you don't see support for your language, please add one to src/lang!
You can also add your own custom language by calling setMessages:
`js`
Validator.setMessages('lang_code', {
required: 'The :attribute field is required.',
})
Get the raw object of messages for the given language:
`js`
Validator.getMessages('lang_code')
Switch the default language used by the validator:
`js`
Validator.useLang('lang_code')
Get the default language being used:
`js`
Validator.getDefaultLang() // returns e.g. 'en'
Override default messages for language:
`js``
const messages = Validator.getMessages('en')
messages.required = 'Whoops, :attribute field is required.'
Validator.setMessages('en', messages)
Copyright © 2020-Present Chantouch Sek
Released under the MIT license
ValidatorJs re-written by Chantouch Sek
E-Mail: chantouchsek.cs83@gmail.com
Twitter @DevidCs83
Website: Chantouch