redux-form-validators

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

Installation

npm install redux-form-validators

Note: For internationalization purposes, this package depends on react-intl.

Example

To run the example project you need to clone the repo and run npm i -d && npm start. Then go to http://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'

<Field name="email" type="email" label="Email" component={renderField} 
    validate={[required(), email()]} />

That's it! =)

Sync validation

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

const TOO_YOUNG_ERROR = (
  <FormattedMessage id="form.errors.tooYoung"
      defaultMessage="Sorry, you must be at least 18 years old">
)

validations = {
  username: [required(), length({ max: 15 })],
  email:    [required(), email()],
  age:      [
    required(), 
    numericality({ int: true }), 
    numericality({ '>=': 18, msg: TOO_YOUNG_ERROR })
  ]
}

// Reusable with any other form
validate = (values) => {
  const errors = {}
  for (let field in validations) {
    let value = values[field]
    errors[field] = validations[field].map(validateField => {
      return validateField(value, values)
    }).find(x => x)
  }
  return errors
}

Documentation

Validators

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

More

• adding a validator
• common validation options
• conditional validation
• date helpers

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.

<Field name="login" type="text" label="Login" component={renderField} 
    validate={required()} />

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 internal REG_EMAIL regexp to check the value.

<Field name="email" type="email" label="Email" component={renderField} 
    validate={email()} />

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

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.

<Field name="lat" type="text" label="Latitude" component={renderField} 
    validate={numericality()} />

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 message is "is not a number".

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).

<Field name="date" type="text" label="Date" component={renderField} 
    validate={date({ format: 'mm/dd/yyyy' })} />

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.

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:

<Field name="name" type="text" label="Name" component={renderField} 
    validate={length({ min: 2 })} />

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.

<Field name="pass" type="password" label="Password" component={renderField} />
<Field name="confirmation" type="password" label="Confirmation" component={renderField} 
    validate={confirmation({ field: 'pass', fieldLabel: 'Password' })} />

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.

Examples

confirmation({ field: '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.

const ALPHA_ERROR = <FormattedMessage id="form.errors.alpha"
      defaultMessage="Only allows letters">
 
<Field name="legacyCode" type="text" label="Legacy Code" component={renderField} 
    validate={format({ with: /^[a-z]+$/i, message: ALPHA_ERROR })} />

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.

<Field name="terms" type="checkbox" label="I accept the terms of service" 
    component={renderField} validate={acceptance()} />

It can also receive an accept option, which determines the allowed values that will be considered as accepted. It defaults to ['1', 'true'] and can be easily changed (via the msg or message parameter).

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.

<Field name="size" type="text" label="Size" component={renderField} 
    validate={inclusion({ in: ['small', 'medium', 'large'] })} />

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.

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.

<Field name="subdomain" type="text" label="Subdomain" component={renderField} 
    validate={exclusion({ in: ['www', 'us', 'ca'] })} />

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.

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.

<Field name="name" type="text" label="Name" component={renderField} 
    validate={absence()} />

The default error message is "must be blank".

url

Validates that the specified value is a valid URL. It uses the internal REG_URL regexp to check the value.

<Field name="url" type="text" label="URL" component={renderField} 
    validate={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', 'ftp'].

Examples

url({ protocol: 'http' })
url({ protocol: 'ftp' })
url({ protocols: ['http', 'https'] })

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

Common validation options

allowBlank

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

<Field name="name" type="text" label="Name" component={renderField} 
    validate={length({ '=': 5, allowBlank: true })} />

Not available for: required, absence, acceptance & confirmation.

Note: If you're already using the required validator you don't need to care about the allowBlank option.

message (alias: msg)

As you've already seen, the message option lets you specify the message that will be added to the errors collection when validation fails. When this option is not used, redux-form-validators will use the respective default error message for each validator. The message option accepts a String, a Hash or a FormattedMessage.

const ALPHA_ERROR = <FormattedMessage id="form.errors.alpha"
      defaultMessage="Letters only">
 
format({ with: /^[a-z]+$/i, message: ALPHA_ERROR })
format({ with: /^[a-z]+$/i, message: { id: 'form.errors.alpha' } })
format({ with: /^[a-z]+$/i, message: 'form.errors.alpha' })
format({ with: /^[a-z]+$/i, message: { id: 'form.errors.alpha', defaultMessage: 'Letters only' } })

Or alternatively, if you don't care about i18n:

format({ with: /^[a-z]+$/i, message: 'Letters only' })

This will be wrapped in a FormattedMessage (with the message as id), will look for a message with this id and will finally fallback to the id.

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.

<Field name="surname" type="text" label="Surname" component={renderField} 
    validate={presence({ if: (value, values) => { return '' !== values.name } })} />

Adding a validator

const ALPHA_ERROR = <FormattedMessage id="form.errors.alpha"
      defaultMessage="Letters only">

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

<Field name="name" type="text" label="Name" component={renderField} 
    validate={alphaValidator({ lowerCase: true, allowBlank: true })} />

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

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

Date helpers

parseDate

parser used to validate dates.

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

Examples:

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:

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