redux-form-validators

Simple validations with redux-form / react-final-form. Heavily inspired by the rails validations.

Installation | Demo | Documentation | ☕️Send some love ❤️

Installation

npm install redux-form-validators

> Note: For internationalization purposes, this package is compatible with react-intl.

Demo

Live demo -> FieldLevelValidationForm.js

Or you can also run the example project. Just clone the repo, run npm i -d && npm start and then go to https://localhost:3003/

How to use

If you're already familiar with redux-form it should be pretty straight forward:

Field validation

This example shows you how to set a field level validation with redux-form. Thanks to redux-form-validators, you'll only have to pass the validators needed:

import { required, email } from 'redux-form-validators'

That's it! =)

Sync validation

Now let's replace the validate function of this redux-form example:

const validate = validateForm({
  username: [required(), length({ max: 15 })],
  email: [required(), email()],
  age: [
    required(),
    numericality({
      int: true,
      '>=': 18,
      msg: { '>=': 'You must be at least 18 years old' },
    }),
  ],
})

Documentation

Validators

• required / presence
• email
• numericality
• date
• length
• confirmation
• format
• acceptance
• inclusion
• exclusion
• absence
• url
• file

Form

• validateForm
• combine

More

• default options
• memoization
• i18n and react-intl
• default messages override
• common validation options
• conditional validation
• adding a validator
• date helpers
• url helper

required (alias: presence)

Validates that the specified value is not empty. It uses the trim() method to check if the value is a blank string, that is, a string that is either empty or consists of whitespace.

The default error message is "is required". You can also pass custom message via the message option.

email

Validates that the specified value is a valid email address. It uses the email.REG_EMAIL regexp to check the value.

This validator also provides 2 options to check (case insensitive) the domain:

• domainWhitelist - Specifies a list of domains allowed
• domainBlacklist - Specifies a list of domains not allowed

Examples

email({ domainWhitelist: ['GOOGLE.COM', 'outlook.*'] })
email({ domainWhitelist: ['*.fr'] })

// Disposable email addresses
email({ domainBlacklist: ['yopmail.com', 'guerrillamail.*'] })

The default error messages are:

• "is not a valid email"
• "{domain} is not an accepted domain"

numericality

Validates that your value have only numeric values. By default, it will match an optional sign followed by an integral or floating point number. To specify that only integral numbers are allowed set int (or integer) to true.

Besides int, this validator also accepts the following options to add constraints to acceptable values:

• > (or greaterThan) - Specifies the value must be greater than the supplied value. The default error message for this option is "must be greater than ${count}".
• >= (or greaterThanOrEqualTo) - Specifies the value must be greater than or equal to the supplied value. The default error message for this option is "must be greater than or equal to ${count}".
• = (or equalTo) - Specifies the value must be equal to the supplied value. The default error message for this option is "must be equal to ${count}".
• != (or otherThan) - Specifies the value must be other than the supplied value. The default error message for this option is "must be other than 4{count}".
• < (or lessThan) - Specifies the value must be less than the supplied value. The default error message for this option is "must be less than ${count}".
• <= (or lessThanOrEqualTo) - Specifies the value must be less than or equal to the supplied value. The default error message for this option is "must be less than or equal to ${count}".
• odd - Specifies the value must be an odd number if set to true. The default error message for this option is "must be odd".
• even - Specifies the value must be an even number if set to true. The default error message for this option is "must be even".

Examples

numericality({ int: true })
numericality({ '>': 6 })
numericality({ '>': 6, '<=': 20 })
numericality({ int: true, odd: true })

The default error messages are:

• "is not a number"
• "must be greater than {number}"
• "must be greater than or equal to {number}"
• "must be equal to {number}"
• "must be other than {number}"
• "must be less than {number}"
• "must be less than or equal to {number}"
• "must be odd"
• "must be even"

date

Very simple date validator. Limited to year, month and day validation (but it should mostly match your needs). Feel free to use a date manipulation lib to write a better date validator (see add a validator).

Accepts the following options:

• format - Specifies the format that should match the date string. Accepts only the current flags: y, m & d. The number of flags used represents the number of digits expected (e.g. yyyy expects 4 digits while yy expects 2). Format examples: mm/dd/yyyy, dd/mm/yyyy, yyyy-mm-dd, mm/dd/yy, yyyy/mm, mm/dd...
• ymd - Allows you to customize the format, to be more readable in case you're using i18n. For instance, you could use { format: 'jj/mm/aaaa', ymd: 'amj' } for a French format.

(See default options to set format and ymd globally)

And the comparable options:

• '=', '>', '>=', '<', '<='. All of these options accept either a Date object, a timestamp, or a function (which returns a Date or a timestamp). To avoid syncing issues, don't pass new Date() directly but wrap it in a function or just pass the string 'today'. Note that these options are only available if these flags are present: y + m + d OR y + m OR just y)

Examples

date({ format: 'mm/dd/yyyy' })
date({ format: 'mm/yyyy' })
date({ format: 'YYYY-MM-DD', ymd: 'YMD' })
date({ format: 'dd/mm/yyyy', '<': new Date(2020, 0, 1), '>=': new Date(1980, 0, 1) })
date({ format: 'mm/dd/yyyy', '>': 'today', msg: 'must be in the future' })
date({ format: 'mm/dd/yyyy', '<=': twentyYearsAgo, msg: 'you must be at least 20 years old' })

function twentyYearsAgo() {
  let d = new Date()
  d.setFullYear(d.getFullYear() - 20)
  return d
}

The default error messages are:

• "expected format: {format}"
• "is not a valid date" (e.g. Feb 29 2017)
• "should be {op} {date}" (e.g. 'should be > 01/14/2017')

See also parseDate & formatDate

length

Validates the length of the value. It provides a variety of options, so you can specify length constraints in different ways:

The possible length constraint options are:

• min (or minimum) - The value cannot have less than the specified length.
• max (or maximum) - The value cannot have more than the specified length.
• in (or within) - The value length must be included in a given interval. The value for this option must be an array.
• is (or =) - The value length must be equal to the given value.

Examples

length({ minimum: 2 })
length({ min: 2, max: 8 })
length({ in: [2, 8] })
length({ is: 6 })

The default error messages depend on the type of length validation being performed. You can personalize these messages using the wrongLength, tooLong, and tooShort options and ${count} as a placeholder for the number corresponding to the length constraint being used. You can still use the msg (or message) option to specify an error message (don't forget to pluralize it).

confirmation

You should use this validator when you have two text fields that should receive exactly the same content. For example, you may want to confirm an email address or a password.

// Within a FormSection

  
  

There is also a caseSensitive option that you can use to define whether the confirmation constraint will be case sensitive or not. This option defaults to true (see default options).

Examples

confirmation({ field: 'email' })
confirmation({ field: 'section.email' })
confirmation({ field: 'email', fieldLabel: 'Email' })
confirmation({ field: 'email', fieldLabel: 'Email', caseSensitive: false })

The default error message for this validator is "doesn't match ${fieldLabel || field}".

format

Validates the value by testing whether it match a given regular expression, which is specified using the with option.

Alternatively, you can require that the specified value does not match the regular expression by using the without option.

Examples

format({ with: /[a-z0-9]/i })
format({ without: /#@%&\!\:\?\+\=/i }) // doesn't allow these chars: '#@%&!:?+='

The default error message is "is invalid".

acceptance

This method validates that a checkbox on the user interface was checked. This is typically used when the user needs to agree to your application's terms of service, confirm that some text is read, or any similar concept.

It can also receive an accept option, which determines the allowed values that will be considered as accepted. It defaults to ['1', 'true'] (see default options).

Examples

acceptance({ accept: 'yes' })
acceptance({ accept: ['TRUE', 'accepted'] })

The default error message for this validator is "must be accepted".

inclusion

Validates that the value is included in a given set.

The inclusion validator has an option in that receives the set of values that will be accepted. The in option has an alias called within that you can use for the same purpose, if you'd like to.

There is also a caseSensitive option that you can use to define whether the match will be case sensitive or not. This option defaults to true (see default options).

Examples

inclusion({ in: [1, 2, 3, 4] })
inclusion({ in: ['blue', 'white', 'red'], caseSensitive: false })

The default error message for this validator is "is not included in the list".

exclusion

Validates that the value is not included in a given set.

The exclusion validator has an option in that receives the set of values that will not be accepted for the validated attributes. The in option has an alias called within that you can use for the same purpose, if you'd like to.

There is also a caseSensitive option that you can use to define whether the match will be case sensitive or not. This option defaults to true (see default options).

Examples

exclusion({ in: [1, 2, 3, 4] })
exclusion({ in: ['apple', 'banana'], caseSensitive: false })

The default error message is "${value} is reserved".

absence

Validates that the specified value are absent. It uses the trim() method to check if the value is not a blank string, that is, a string that is either empty or consists of whitespace.

The default error message is "must be blank".

url

Validates that the specified value is a valid URL.

The url validator has an option protocol (or its alias protocols) that receives the set of protocols that will be accepted. This option default to ['http', 'https'] (see default options).

The other url constraint options are (all true by default):

• protocolIdentifier - if set to false your URL doesn't have to start with {{protocol}}://
• emptyProtocol - if set to false, doesn't accept URLs starting just with //
• basicAuth - accepts or not basic authentication
• ipv4 - accepts or not an IPv4 address as a host
• ipv6 - accepts or not an IPv6 address as a host
• host - accepts or not a domain + TLD as a host
• local - accepts or not 'localhost' as a host
• port - accepts or not a port
• path - accepts or not a path
• search - accepts or not a query string
• hash - accepts or not a hash

Examples

url({ protocols: ['http', 'https'] })
url({ protocol: 'http', ipv4: false, ipv6: false })
url({ protocol: 'ftp', port: false, basicAuth: false, hash: false })

The default error message is "is not a valid URL".

See also parseURL

> Note: As of version 3.0.0, this method doesn't exclude any ip addresses anymore (like private & local networks). To re-implement this feature, you can use the url.parseURL helper and add a custom validator, like this:

// Private and local networks not allowed
const REG = new RegExp(
  '^(?:(?:10|127)(?:\\.\\d{1,3}){3})|' +
    '(?:(?:169\\.254|192\\.168)(?:\\.\\d{1,3}){2})|' +
    '(?:172\\.(?:1[6-9]|2\\d|3[0-1]))'
)

const ipValidator = addValidator({
  validator: function(options, value, allValues) {
    let info = url.parseURL(value, options)
    if (!info) return false
    if (info.ipv4 && REG.test(info.ipv4)) {
      return {
        id: 'form.errors.private_url',
        defaultMessage: 'Private and local networks are not allowed',
      }
    }
  }
})

file

Validates that the specified value is a valid File or FileList.

The possible file constraint options are:

• accept - The value is a file (or a list of files) that match a comma-separated list of allowed file extensions or MIME types
• minSize - The value is a file (or a list of files) that cannot be smaller than the specified size
• maxSize - The value is a file (or a list of files) that cannot be bigger than the specified size
• minFiles - The value is a list of files that cannot be smaller than the specified length
• maxFiles - The value is a list of files that cannot be bigger than the specified length

Examples

file()
file({ accept: 'image/png, image/jpeg' })
file({ accept: '.png, .jpg, .jpeg' })
file({ accept: 'image/*' }) // Accept any file with an image/* MIME type
file({ minSize: '5 MB', maxSize: '1 TB' })
file({ minFiles: 2, maxFiles: 5 })

The default error messages are:

• "is not a file"
• "invalid file type" / "invalid file types ({count})"
• "is too small (minimum is {size})" / "{count} files are too small (minimum is {size} each)"
• "is too big (maximum is {size})" / "{count} files are too big (maximum is {size} each)"
• "invalid number of files (minimum is {count})"
• "invalid number of files (maximum is {count})"

> Note: size units supported: B, KB, MB, GB, TB, PB, EB

> Note: file inputs are only compatible with file, required or absence validators

> Note: incorrect minSize or maxSize options will display an error in the console

> Note: for an optional file input, don't forget to pass allowBlank: true

validateForm

Helper that turns a validation object into a validate function.

Examples

import { required, length, validateForm } from 'redux-form-validators'

const validate = validateForm({
  firstName: required(),
  lastName: required(),
  // FormSection
  secureSection: {
    password: [required(), length({ min: 8 }),
    confirmation: confirmation({ field: 'secureSection.password' })
  }
})

...

export default reduxForm({
  form: 'validationFormExample',
  validate,
})(ValidationFormExample)

> Note: For performance reasons, validateForm is not memoized. Use it always outside of the render function to avoid problems.

combine

Combine several validators. This helper exists for 2 reasons:

• when validators are combined using an array, it sometimes forces the component to be re-rendered (thank you @futpib for pointing it out). This is due to the way React handle properties comparison. This demo shows the issue (see how the email field is forced to be re-rendered).
• react-final-form doesn't support arrays of validators.

Examples

> Note: You don't need to use combine with validateForm

Default options

redux-form-validators comes with default options:

{
  memoize:       true,
  allowBlank:    false,
  urlProtocols:  ['http', 'https'],
  dateFormat:    'yyyy-mm-dd',
  dateYmd:       'ymd',
  accept:        ['1', 'true'],
  caseSensitive: true,  // confirmation, inclusion, exclusion
  pluralRules: { // See the "i18n and react-intl" section
    0: 'zero',
    1: 'one'
  }
};

But you can easily change them:

import Validators from 'redux-validators'

// Override dateFormat & urlProtocols
Object.assign(Validators.defaultOptions, {
  dateFormat: 'mm/dd/yyyy',
  urlProtocols: ['http', 'https', 'ftp'],
})

Memoization

Since version 7.0 of Redux-form, memoization is needed for inline validation. In some cases, you might want to disable it though. To do so:

• set Validators.defaultOptions.memoize to false
• OR set memoize validator's option to false (e.g. presence({ memoize: false }))

And if you want to keep the memoization but want to override it:

// Global memoization
// This function usually returns a unique key depending on the options passed
// $super represents the default memoize function
Validators.defaultOptions.memoize = (options, $super) => {
  return ... // string key
}

// Specific validation (inline-validation)
length({
  min: 2,
  if: () => this.state.foo,
  memoize: (opts, $super) => $super(opts) + this.state.foo
})

// General validation
const validLen = length({ min: 2, if: () => ..., memoize: false })

i18n and react-intl

By default, all errors messages are in english and are pluralized if needed (basic support) but you can use react-intl to support different languages. All you need to do is to insert the following lines:

import Validators from 'redux-form-validators'
import { FormattedMessage } from 'react-intl'

Validators.formatMessage = function(msg) {
  return 
}

> Note: You can also implement your own i18n/pluralization module by overriding Validators.formatMessage. The first argument is a javascript object compatible with react-intl:

{
  id: "form.errors.greaterThan",
  defaultMessage: "must be greater than {count, number}",
  values: { count: 10 }
}

> Note: You can also change the default plural rules or file size formats:

// Plural rules
Validators.pluralRules = {
  1: 'one', 5: 'one', 7: 'one', 8: 'one', 9: 'one', 10: 'one',
  2: 'two', 3: 'two',
  4: 'few',
  6: 'many'
}
let msg = '{count, plural, one {foo} two {bar} few {fooo} many {baaar} other {foobar}}'

// Size format
const FR_UNITS = {
  B:  'octets',
  KB: 'Ko',
  ...
}
Validators.formatSize = function (size, unit) {
  return size + ' ' + FR_UNITS[unit]
}
file({ minSize: '5MB' }) // -> is too small (minimum is 5 Mo)
file({ minSize: 500 })   // -> is too small (minimum is 500 octets)

And if you're using babel-plugin-react-intl to extract your application messages, you'll need to add a new plugin entry in your webpack config (example):

["react-intl", {
  "messagesDir": ...,
  "languages": ...,
  // /!\ it's important to keep a relative path here
  "moduleSourceName": "./redux-form-validators",
}, 'redux-form-validators']

Default messages override

To override the default messages globally:

Object.assign(Validators.messages, {
  email: {
    id: "form.errors.email",
    defaultMessage: "is not a valid email address"
  },
  presence: {
    id: "form.errors.presence",
    defaultMessage: "is missing"
  },
  tooShort: {
    id: "form.errors.tooShort",
    defaultMessage: "is too short: {count, number} chars minimum"
  },
  ...
})

OR even simpler if you don't override formatMessage (and don't need ids):

Object.assign(Validators.messages, {
  email:    "is not a valid email address",
  presence: "is missing",
  tooShort: "is too short: {count, number} chars minimum",
  ...
})

> Note: This won't work with react-intl, as you load the messages from a json file

See all default messages.

Common validation options

allowBlank

This option will let validation pass if the value is blank, like an empty string for example.

 })

// Redefine only certain messages and use interpolation
length({ msg: { tooShort: 'too short', tooLong: 'too long' }, in: [2, 8] })
length({ msg: { tooShort: { id: 'errors.length.min',
  defaultMessage: 'too short' } }, min: 2 })
length({ msg: { tooShort:  }, min: 2 })
length({ msg: { tooShort: 'min {count, number} characters' }, min: 2, max: 8 })
  //=> tooLong message remains the default message

// Version >= 3.3.0 (aliases)
length({ msg: { min: 'too short', max: 'too long' }, in: [2, 8] })
numericality({ msg: { '>=': 'must be at least {count, number} years old' }, '>=': 18 })
date({ msg: { '>': 'must be in the future' }, '>': 'today' })

Message key aliases

Date

• 'dateFormat', 'format'
• 'dateInvalid', 'invalid'
• 'dateRange', 'range', '=', '!=', '>', '>=', '<', '<=' (operators only match with their specific validation)

Email

• 'email', 'invalid'
• 'emailDomain', 'domain'

File

• 'fileTooFew', 'tooFew', 'minFiles'
• 'fileTooMany', 'tooMany', 'maxFiles'
• 'fileAccept', 'accept'
• 'fileTooSmall', 'tooSmall', 'minSize'
• 'fileTooBig', 'tooBig', 'maxSize'

Length

• 'wrongLength', 'is', '='
• 'tooLong', 'maximum', 'max'
• 'tooShort', 'minimum', 'min'

Numericality

• 'notANumber', 'NaN'
• 'notAnInteger', 'int'
• 'equalTo', '='
• 'otherThan', '!='
• 'greaterThan', '>'
• 'greaterThanOrEqualTo', '>='
• 'lessThan', '<'
• 'lessThanOrEqualTo', '<='

> Note: all messages are internally converted into javascript objects (see i18n and react-intl), so if you pass a FormattedMessage as an argument, don't expect it to be returned as it.

See all default messages.

Conditional validation

Using a function with if and unless

Finally, it's possible to associate if and unless with a function which will be called. Using a function gives you the ability to write an inline condition instead of a separate method. This option is best suited for one-liners.

 '' !== values.name })} />

> Note: In some cases, the memoization can mess with if and unless methods which can refer to out-of-the-scope variables. See memoization for further information.

Adding a validator

const alphaValidator = addValidator({
  defaultMessage: "Letters only",
  validator: function(options, value, allValues) {
    return (options.lowerCase ? /^[a-z]+$/ : /^[a-z]+$/i).test(value)
  }
})



// Version >= 2.0.0 only
const digitValidator = addValidator({
  validator: function(options, value, allValues) {
    if (options.digits !== value.replace(/[^0-9]/g, '').length) {
      return {
        id: "form.errors.custom"
        defaultMessage: "must contain {count, number} {count, plural, one {digit} other {digits}})"
        values: { count: options.digits }
      }
    }
  }
})

defaultMessage accepts a String, a Hash or a FormattedMessage. See the message option. Its default value is is not valid.

> Note: As of version 2.0.0, you can now return a message directly if invalid (allowing things like pluralization). For backward compatibility, if you return a boolean, the validator will return the defaultMessage if invalid.

> Note: you'll still be able to use the common options (message, allowBlank & memoize) and the conditional validation (if and unless).

Date helpers

parseDate

parser used to validate dates.

Signature: parseDate(dateString, format[, ymd])

Examples:

import { date } from 'redux-form-validators'
let parseDate = date.parseDate

parseDate('12/31/2017', 'mm/dd/yyyy')        => new Date(2017, 11, 31)
parseDate('2016/01',    'yyyy/mm'))          => new Date(2016,  1,  1)
parseDate('12/01',      'mm/dd'))            => new Date(1970, 11,  1)

// Custom ymd
parseDate('12/31/2017', 'mm/jj/aaaa', 'amj') => new Date(2017, 11, 31)

// Error
parseDate('12122016',   'mm/dd/yyyy')        => Invalid date

formatDate

formatter used to display dates.

Signature: formatDate(date, format[, ymd])

Examples:

import { date } from 'redux-form-validators'
let formatDate = date.formatDate

formatDate(new Date(2017, 11, 31), 'mm/dd/yyyy')        => '12/31/2017'
formatDate(new Date(2016,  1,  1), 'yyyy/mm'))          => '2016/01'
formatDate(new Date(1970, 11,  1), 'mm/dd'))            => '12/01'

// Custom ymd
formatDate(new Date(2017, 11, 31), 'mm/jj/aaaa', 'amj') => '12/31/2017'

// Error
formatDate(new Date(NaN), 'mm/dd/yyyy')                 => null
formatDate(null,          'mm/dd/yyyy')                 => null
formatDate({},            'mm/dd/yyyy')                 => null

URL helper

parseURL

parser used to validate URLs

Signature: parseURL(url[, options])

• options are the same as described for url
• returns null if invalid
• otherwise returns an object filled with the elements found

Examples:

import { url } from 'redux-form-validators'
let parseURL = url.parseURL

parseURL('https://example.com/stuff')
// { protocol: 'http', host: 'example.com', path: '/stuff' }

parseURL('https://localhost:8080')
// { protocol: 'http', host: 'localhost', port: 8080 }

parseURL('//212.78.3.17:4000')
// { ipv4: '212.78.3.17', port: 4000 }

parseURL('https://[::1]:3000')
// { ipv6: '::1', port: 3000, protocol: 'http' }

parseURL('https://userid:pass@example.com')
// { basicAuth: { username: 'userid', password: 'pass' }, ... }

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