Need help with ember-changeset-validations?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

213 Stars 89 Forks Other 292 Commits 29 Opened issues


Validations for ember-changeset

Services available


Need anything else?

Contributors list

ember-changeset-validations: Validations for ember-changeset

Download count all time TravisCI Build Status npm version Ember Observer Score

is a companion validation library to
. It's really simple to use and understand, and there are no CPs or observers anywhere – it's mostly just functions.


is required to use this addon, please see documentation there on how to use changesets.

To install if your app is on ember-source >= 3.13:

ember install ember-changeset-validations

To install if your app is on ember-source < 3.13:

ember install [email protected]

This will also install


Watch a 6-part video series on ember-changeset and ember-changeset-validations presented by EmberScreencasts.


This addon updates the

helper by taking in a validation map as a 2nd argument (instead of a validator function). This means that you can very easily compose validations and decouple the validation from the underlying model.
{{! application/template.hbs}}

A validation map is just a POJO (Plain Old JavaScript Object). Use the bundled validators from

to compose validations or write your own. For example:
// validations/employee.js
import {
} from 'ember-changeset-validations/validators';
import validateCustom from '../validators/custom'; // local validator
import validatePasswordStrength from '../validators/password-strength'; // local validator

export default { firstName: [ validatePresence(true), validateLength({ min: 4 }) ], lastName: validatePresence(true), age: validateCustom({ foo: 'bar' }), email: validateFormat({ type: 'email' }), password: [ validateLength({ min: 8 }), validatePasswordStrength({ minScore: 80 }) ], passwordConfirmation: validateConfirmation({ on: 'password' }) };

Then, you can use the POJO as a property on your Component or Controller and use it in the template:

import Component from '@glimmer/component';
import EmployeeValidations from '../validations/employee';
import AdminValidations from '../validations/admin';

export default class EmployeeComponent extends Component { EmployeeValidations; AdminValidations; }

Moreover, as of 3.8.0, a validator can be an Object or Class with a

import fetch from 'fetch';

export default class PersonalNoValidator {

async validate(key, newValue, oldValue, changes, content) { try { await fetch( '/api/personal-no/validation', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ data: newValue }) } );

  return true;
} catch (_) {
  return 'Personal No is invalid';

} }

When creating the

programmatically instead of using the
helper, you will have to apply the
function to convert the POJO to a validator function as expected by
import Component from '@glimmer/component';
import EmployeeValidations from '../validations/employee';
import lookupValidator from 'ember-changeset-validations';
import Changeset from 'ember-changeset';

export default class ChangesetComponent extends Component { constructor() { super(...arguments); this.changeset = new Changeset(this.model, lookupValidator(EmployeeValidations), EmployeeValidations); } }

both also support creating changesets from promises. However, because that will also return a promise, to render in your template you will need to use a helper like

Validator API

as a core set of validators.

All validators take a custom message option.


Validates presence/absence of a value.

👉 All Options

  propertyName: validatePresence(true), // must be present
  propertyName: validatePresence(false) // must be blank
  propertyName: validatePresence({ presence: true }) // alternative option syntax
  propertyName: validatePresence({ presence: true, ignoreBlank: true }) // If ignoreBlank true, treats an empty or whitespace string as not present.

option for

Only validates for presence if any of the other values are present

  password: validatePresence({ presence: true, on: 'ssn' })
  password: validatePresence({ presence: true, on: [ 'ssn', 'email', 'address' ] })
  password: validatePresence({ presence: false, on: 'alternative-login' })

⬆️ back to top


Validates the length of a

or an

👉 All Options

  propertyName: validateLength({ min: 1 }), // 1 or more
  propertyName: validateLength({ max: 8 }), // up to 8
  propertyName: validateLength({ min: 1, max: 8 }), // between 1 and 8 (inclusive)
  propertyName: validateLength({ is: 16 }), // exactly 16
  propertyName: validateLength({ allowBlank: true }) // can be blank

⬆️ back to top


This API accepts valid Date objects or a Date in milliseconds since Jan 1 1970, or a functiom that returns a Date. Strings are currently not supported. It is recommended you use use native JavaScript or you library of choice to generate a date from your data.

  propertyName: validateDate({ before: new Date('3000-01-01') }), // must be before 1st Jan. 3000
  propertyName: validateDate({ onOrBefore: Date.parse(new Date('3000-01-01')) }), // must be not after 1st Jan. 3000
  propertyName: validateDate({ after: new Date('3000-01-01') }), // must be after 1st Jan. 3000
  propertyName: validateDate({ onOrAfter: new Date('3000-01-01') }), // must be not before 1st Jan. 3000
  propertyName: validateDate({ onOrAfter: () => new Date() }), // must not be in the past
  propertyName: validateDate({ onOrAfter: '3000-01-01' }), // Error

⬆️ back to top


Validates various properties of a number.

👉 All Options

  propertyName: validateNumber({ is: 16 }), // exactly 16
  propertyName: validateNumber({ allowBlank: true }), // can be blank
  propertyName: validateNumber({ integer: true }), // must be an integer
  propertyName: validateNumber({ lt: 10 }), // less than 10
  propertyName: validateNumber({ lte: 10 }), // less than or equal to 10
  propertyName: validateNumber({ gt: 5 }), // greater than 5
  propertyName: validateNumber({ gte: 10 }), // greater than or equal to 10
  propertyName: validateNumber({ positive: true }), // must be a positive number
  propertyName: validateNumber({ odd: true }), // must be an odd number
  propertyName: validateNumber({ even: true }), // must be an even number
  propertyName: validateNumber({ multipleOf: 7 }) // must be a multiple of 7

⬆️ back to top


Validates that a value is a member of some list or range.

👉 All Options

  propertyName: validateInclusion({ list: ['Foo', 'Bar'] }), // must be "Foo" or "Bar"
  propertyName: validateInclusion({ range: [18, 60] }), // must be between 18 and 60
  propertyName: validateInclusion({ allowBlank: true }), // can be blank

⬆️ back to top


Validates that a value is a not member of some list or range.

👉 All Options

  propertyName: validateExclusion({ list: ['Foo', 'Bar'] }), // cannot be "Foo" or "Bar"
  propertyName: validateExclusion({ range: [18, 60] }), // must not be between 18 and 60
  propertyName: validateExclusion({ allowBlank: true }), // can be blank

⬆️ back to top


Validates a

based on a regular expression.

👉 All Options

  propertyName: validateFormat({ allowBlank: true }), // can be blank
  propertyName: validateFormat({ type: 'email' }), // built-in email format
  propertyName: validateFormat({ type: 'phone' }), // built-in phone format
  propertyName: validateFormat({ type: 'url' }), // built-in URL format
  propertyName: validateFormat({ regex: /\w{6,30}/ }) // custom regular expression
  propertyName: validateFormat({ type: 'email', inverse: true }) // passes if the value doesn't match the given format

⬆️ back to top


Validates that a field has the same value as another.

👉 All Options

  propertyName: validateConfirmation({ on: 'password' }), // must match 'password'
  propertyName: validateConfirmation({ allowBlank: true }), // can be blank

⬆️ back to top

Writing your own validators

Adding your own validator is super simple – there are no Base classes to extend! Validators are just functions. All you need to do is to create a function with the correct signature.

Create a new validator using the blueprint:

ember generate validator 

expects a higher order function that returns the validator function. The validator (or inner function) accepts a
, and
. The outer function accepts options for the validator.

Synchronous validators

For example:

// validators/custom.js
export default function validateCustom({ min, max } = {}) {
  return (key, newValue, oldValue, changes, content) => {
    // validation logic
    // return `true` if valid || error message string if invalid

Asynchronous validators

In addition to conforming to the function signature above, your validator function should return a Promise that resolves with

(if valid), or an error message string if invalid.

For example:

export default function validateUniqueness(opts) {
  return (key, newValue, oldValue, changes, content) => {
    return new Promise((resolve) => {
      // validation logic
      // resolve with `true` if valid || error message string if invalid

Using custom validators

That's it! Then, you can use your custom validator like so:

// validations/custom.js
import { validateLength } from 'ember-changeset-validations/validators';
import validateUniqueness from '../validators/unique';
import validateCustom from '../validators/custom';

export default { firstName: validateCustom({ min: 4, max: 8 }), lastName: validateCustom({ min: 1 }), email: [ validateFormat({ type: 'email'}), validateUniqueness() ] };


Since validators are higher order functions that return functions, testing is straightforward and requires no additional setup:

import validateUniqueness from 'path/to/validators/uniqueness';
import { module, test } from 'qunit';

module('Unit | Validator | uniqueness');

test('it does something', function(assert) { let key = 'email'; let options = { /* ... */ }; let validator = validateUniqueness(options);

assert.equal(validator(key, undefined), /* ... /); assert.equal(validator(key, null), / ... /); assert.equal(validator(key, ''), / ... /); assert.equal(validator(key, '[email protected]'), / ... */); });

Validation composition

Because validation maps are POJOs, composing them couldn't be simpler:

// validations/user.js
import {
} from 'ember-changeset-validations/validators';

export default { firstName: validatePresence(true), lastName: validatePresence(true) };

You can easily import other validations and combine them using

// validations/adult.js
import UserValidations from './user';
import { validateNumber } from 'ember-changeset-validations/validators';

export const AdultValidations = { age: validateNumber({ gt: 18 }) };

export default Object.assign({}, UserValidations, AdultValidations);

Custom validation messages

Each validator that is a part of this library can utilize a

property on the
object passed to the validator. That
property can either be a string or a function.


is a string, you can put particular placeholders into it that will be automatically replaced. For example:
  propertyName: validatePresence({ presence: true, message: '{description} should be present' })

is a hardcoded placeholder that will be replaced with a normalized version of the property name being validated. Any other placeholder will map to properties of the
object you pass to the validator.

Message can also accept a function with the signature

(key, type, value, context)
. Key is the property name being validated. Type is the type of validation being performed (in the case of validators such as
, there can be a couple of different ones.) Value is the actual value being validated. Context maps to the
object you passed to the validator.


is a function, it must return the error message as a string.

Overriding validation messages

If you need to be able to override the entire validation message object, simply create a module at

, exporting a POJO with the following keys:
// app/validations/messages.js
export default {
  inclusion: // '{description} is not included in the list',
  exclusion: // '{description} is reserved',
  invalid: // '{description} is invalid',
  confirmation: // "{description} doesn't match {on}",
  accepted: // '{description} must be accepted',
  empty: // "{description} can't be empty",
  blank: // '{description} must be blank',
  present: // "{description} can't be blank",
  collection: // '{description} must be a collection',
  singular: // "{description} can't be a collection",
  tooLong: // '{description} is too long (maximum is {max} characters)',
  tooShort: // '{description} is too short (minimum is {min} characters)',
  between: // '{description} must be between {min} and {max} characters',
  before: // '{description} must be before {before}',
  onOrBefore: // '{description} must be on or before {onOrBefore}',
  after: // '{description} must be after {after}',
  onOrAfter: // '{description} must be on or after {onOrAfter}',
  wrongDateFormat: // '{description} must be in the format of {format}',
  wrongLength: // '{description} is the wrong length (should be {is} characters)',
  notANumber: // '{description} must be a number',
  notAnInteger: // '{description} must be an integer',
  greaterThan: // '{description} must be greater than {gt}',
  greaterThanOrEqualTo: // '{description} must be greater than or equal to {gte}',
  equalTo: // '{description} must be equal to {is}',
  lessThan: // '{description} must be less than {lt}',
  lessThanOrEqualTo: // '{description} must be less than or equal to {lte}',
  otherThan: // '{description} must be other than {value}',
  odd: // '{description} must be odd',
  even: // '{description} must be even',
  positive: // '{description} must be positive',
  multipleOf: // '{description} must be a multiple of {multipleOf}',
  date: // '{description} must be a valid date',
  email: // '{description} must be a valid email address',
  phone: // '{description} must be a valid phone number',
  url: // '{description} must be a valid url'

In the message body, any text wrapped in single braces will be replaced with their appropriate values that were passed in as options to the validator. For example:

import buildMessage from 'ember-changeset-validations/utils/validation-errors';
// validators/custom.js
export default function validateIsOne(options) {
  return (key, newValue, oldValue, changes, content) => {
    return newValue === 1 || buildMessage(key, { type: 'isOne', value: newValue, context: options });
// validations/foo.js
export default {
  mySpecialNumber: validateIsOne({ foo: 'foo' }})

The above will look for a key

in your custom validation map, and use keys defined on the options object (in this case,
) to replace tokens. With the custom validator above, we can add:
// app/validations/messages.js
export default {
  isOne: '{description} must equal one, and also {foo}'

Will render:

My special number must equal one, and also foo

Raw error output

By default,

returns the errors as plain strings. In some situations, it may be preferable for the developer that the library returns a description of the errors; internationalisation (i18n) for example, or finer-grained error output.

To have

return such data structure, add the following to you
let ENV = {
  'changeset-validations': { rawOutput: true }

This will return an object with the following structure, that you can then pass to your applications's error processing:

  value, // the value to validate
  type, // the type of the error (`present`, `blank`...)
  message, // the **unprocessed** error message
  context: {
    description // the description of the field
    // ...and other options given to configure the validator


We're grateful to these wonderful contributors who've contributed to



  • git clone 
    this repository
  • cd ember-changeset-validations
  • npm install


Running Tests

  • npm test
    ember try:each
    to test your addon against multiple Ember versions)
  • ember test
  • ember test --server


  • ember build

For more information on using ember-cli, visit

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.