npm install validated-changeset --save

tl;dr

This library is the base class for functionality in ember-changeset but could be used with any front end framework. Example uses in template assume handlebars.

import { Changeset } from 'validated-changeset';

let changeset = Changeset(user, validatorFn);
user.firstName; // "Michael"
user.lastName; // "Bolton"

changeset.set('firstName', 'Jim');
changeset.set('lastName', 'B');
changeset.get('isInvalid'); // true
changeset.get('errors'); // [{ key: 'lastName', validation: 'too short', value: 'B' }]
changeset.set('lastName', 'Bob');
changeset.get('isValid'); // true

user.firstName; // "Michael"
user.lastName; // "Bolton"

changeset.save(); // sets and saves valid changes on the user
user.firstName; // "Jim"
user.lastName; // "Bob"

Usage

First, create a new Changeset through JavaScript:

import { Changeset } from 'validated-changeset';

export default class FormComponent {
  constructor(...args) {
    let validatorFn = this.validate;
    this.changeset = Changeset(this.model, validatorFn);
  }
}

The helper receives any Object and an optional validator action. If a validator is passed into the helper, the changeset will attempt to call that function when a value changes.

In the above example, when the input changes, only the changeset's internal values are updated. When the submit button is clicked, the changes are only executed if all changes are valid.

On rollback, all changes are dropped and the underlying Object is left untouched.

Full API

Changeset(model, lookupValidator(validationMap), validationMap, { skipValidate: boolean, initValidate: boolean, changesetKeys: string[] });

• model (required)

• validationFunc (optional) - see ember-changeset-validations for usage.

• validationMap (optional) - see ember-changeset-validations for usage.

  note: validationMap might not be inclusive of all keys that can be set on an object.

• changesetKeys (optional) - will ensure your changeset and related isDirty state is contained to a specific enum of keys. If a key that is not in changesetKeys is set on the changeset, it will not dirty the changeset.

• initValidate (optional) - will run the validations and set the validation state when the changeset is created. This option does not support async validations.

Alternative Changeset

We now ship a ValidatedChangeset that is a proposed new API we would like to ship. The goal of this refactor is to remove confusing APIs and externalize validations.

• ✂️ save
• ✂️ cast
• ✂️ merge
• errors are required to be added to the Changeset manually after validate
• validate takes a callback with the sum of changes. In user land you will call changeset.validate((changes) => yupSchema.validate(changes))

import { ValidationChangeset } from 'validated-changeset';
import { array, object, string, number, date } from 'yup';

const UserSchema = object({
  name: string().required(),
  age: number()
    .required()
    .positive()
    .integer(),
  email: string().email(),
  website: string()
    .url()
    .nullable(),
  createdOn: date().default(() => new Date())
});

export default class FormComponent {
  constructor(...args) {
    this.changeset = ValidationChangeset(this.model);
  }

  onSubmit() {
    try {
      await this.changeset.validate(changes => UserSchema.validate(changes));
      this.changeset.removeError()
    } catch (e) {
      dummyChangeset.addError(e.path, { value: changeset.get(e.path), validation: e.message });
    }
  }
}

Examples

• ember-changeset
• svelte example

API

• Properties
  • error
  • change
  • errors
  • changes
  • data
  • isValid
  • isInvalid
  • isPristine
  • isDirty
• Methods
  • get
  • set
  • prepare
  • execute
  • save
  • merge
  • rollback
  • rollbackInvalid
  • rollbackProperty
  • validate
  • addError
  • pushErrors
  • snapshot
  • restore
  • cast
  • isValidating
• Events
  • beforeValidation
  • afterValidation
  • afterRollback

error

Returns the error object.

{
  firstName: {
    value: 'Jim',
    validation: 'First name must be greater than 7 characters'
  }
}

Note that keys can be arbitrarily nested:

{
  address: {
    zipCode: {
      value: '123',
      validation: 'Zip code must have 5 digits'
    }
  }
}

If you have multiple validations, validation will be an array:

{
  address: {
    zipCode: {
      value: '123',
      validation: ['Zip code must have 5 digits', 'too short']
    }
  }
}

You can use this property to locate a single error:

{{#if changeset.error.firstName}}
  <p>{{changeset.error.firstName.validation}}</p>
{{/if}}

{{#if changeset.error.address.zipCode}}
  <p>{{changeset.error.address.zipCode.validation}}</p>
{{/if}}

⬆️ back to top

change

Returns the change object.

{
  firstName: 'Jim'
}

Note that keys can be arbitrarily nested:

{
  address: {
    zipCode: '10001'
  }
}

You can use this property to locate a single change:

{{changeset.change.firstName}}
{{changeset.change.address.zipCode}}

⬆️ back to top

errors

Returns an array of errors. If your validate function returns a non-boolean value, it is added here as the validation property.

[
  {
    key: 'firstName',
    value: 'Jim',
    validation: 'First name must be greater than 7 characters'
  },
  {
    key: 'address.zipCode',
    value: '123',
    validation: 'Zip code must have 5 digits'
  }
]

You can use this property to render a list of errors:

{{#if changeset.isInvalid}}
  <p>There were errors in your form:</p>
  <ul>
    {{#each changeset.errors as |error|}}
      <li>{{error.key}}: {{error.validation}}</li>
    {{/each}}
  </ul>
{{/if}}

⬆️ back to top

changes

Returns an array of changes to be executed. Only valid changes will be stored on this property.

[
  {
    key: 'firstName',
    value: 'Jim'
  },
  {
    key: 'address.zipCode',
    value: 10001
  }
]

You can use this property to render a list of changes:

<ul>
  {{#each changeset.changes as |change|}}
    <li>{{change.key}}: {{change.value}}</li>
  {{/each}}
</ul>

⬆️ back to top

data

Returns the Object that was wrapped in the changeset.

let user = { name: 'Bobby', age: 21, address: { zipCode: '10001' } };
let changeset = Changeset(user);

changeset.get('data'); // user

⬆️ back to top

isValid

Returns a Boolean value of the changeset's validity.

changeset.get('isValid'); // true

You can use this property in the template:

{{#if changeset.isValid}}
  <p>Good job!</p>
{{/if}}

⬆️ back to top

isInvalid

Returns a Boolean value of the changeset's (in)validity.

changeset.get('isInvalid'); // true

You can use this property in the template:

{{#if changeset.isInvalid}}
  <p>There were one or more errors in your form</p>
{{/if}}

⬆️ back to top

isPristine

Returns a Boolean value of the changeset's state. A pristine changeset is one with no changes.

changeset.get('isPristine'); // true

If changes present on the changeset are equal to the content's, this will return true. However, note that key/value pairs in the list of changes must all be present and equal on the content, but not necessarily vice versa:

let user = { name: 'Bobby', age: 21, address: { zipCode: '10001' } };

changeset.set('name', 'Bobby');
changeset.get('isPristine'); // true

changeset.set('address.zipCode', '10001');
changeset.get('isPristine'); // true

changeset.set('foo', 'bar');
changeset.get('isPristine'); // false

⬆️ back to top

isDirty

Returns a Boolean value of the changeset's state. A dirty changeset is one with changes.

changeset.get('isDirty'); // true

⬆️ back to top

get

Exactly the same semantics as Ember.get. This proxies first to the error value, the changed value, and finally to the underlying Object.

changeset.get('firstName'); // "Jim"
changeset.set('firstName', 'Billy'); // "Billy"
changeset.get('firstName'); // "Billy"

changeset.get('address.zipCode'); // "10001"
changeset.set('address.zipCode', '94016'); // "94016"
changeset.get('address.zipCode'); // "94016"

You can use and bind this property in the template:

{{input value=changeset.firstName}}

Note that using Ember.get will not necessarily work if you're expecting an Object. On the other hand, using changeset.get will work just fine:

get(changeset, 'momentObj').format('dddd'); // will error, format is undefined
changeset.get('momentObj').format('dddd');  // => "Friday"

This is because Changeset wraps an Object with Ember.ObjectProxy internally, and overrides Ember.Object.get to hide this implementation detail.

Because an Object is wrapped with Ember.ObjectProxy, the following (although more verbose) will also work:

get(changeset, 'momentObj.content').format('dddd'); // => "Friday"

⬆️ back to top

set

Exactly the same semantics as Ember.set. This stores the change on the changeset. It is recommended to use changeset.set(...) instead of Ember.set(changeset, ...). Ember.set will set the property for nested keys on the underlying model.

changeset.set('firstName', 'Milton'); // "Milton"
changeset.set('address.zipCode', '10001'); // "10001"

You can use and bind this property in the template:

{{input value=changeset.firstName}}
{{input value=changeset.address.country}}

Any updates on this value will only store the change on the changeset, even with 2 way binding.

⬆️ back to top

prepare

Provides a function to run before emitting changes to the model. The callback function must return a hash in the same shape:

changeset.prepare((changes) => {
  // changes = { firstName: "Jim", lastName: "Bob", 'address.zipCode': "07030" };
  let modified = {};

  for (let key in changes) {
    let newKey = key.split('.').map(underscore).join('.')
    modified[newKey] = changes[key];
  }

  // don't forget to return, the original changes object is not mutated
  // modified = { first_name: "Jim", last_name: "Bob", 'address.zip_code': "07030" };
  return modified;
}); // returns changeset

The callback function is not validated – if you modify a value, it is your responsibility to ensure that it is valid.

Returns the changeset.

⬆️ back to top

execute

Applies the valid changes to the underlying Object.

changeset.execute(); // returns changeset

Note that executing the changeset will not remove the internal list of changes - instead, you should do so explicitly with rollback or save if that is desired.

Moreover, if you need to perform additional work on changeset.execute, you can register a callback with a key 'execute' and we will ensure it is carried out whenever changeset.execute is called.

function callback() {
  ...
}
changeset.on('execute', callback);


changeset.execute();

unexecute

Undo changes made to underlying Object for changeset. This is often useful if you want to remove changes from underlying Object if save fails.

changeset
  .save()
  .catch(() => {
    // save applies changes to the underlying Object via this.execute(). This may be undesired for your use case.
    dummyChangeset.unexecute();
  })

⬆️ back to top

save

Executes changes, then proxies to the underlying Object's save method, if one exists. If it does, the method can either return a Promise or a non-Promise value. Either way, the changeset's save method will return a promise.

changeset.save(); // returns Promise

The save method will also remove the internal list of changes if the save is successful.

⬆️ back to top

merge

Merges 2 changesets and returns a Changeset with the same underlying content and validator as the origin. Both changesets must point to the same underlying object. For example:

let changesetA = Changeset(user, validatorFn);
let changesetB = Changeset(user, validatorFn);

changesetA.set('firstName', 'Jim');
changesetA.set('address.zipCode', '94016');

changesetB.set('firstName', 'Jimmy');
changesetB.set('lastName', 'Fallon');
changesetB.set('address.zipCode', '10112');

let changesetC = changesetA.merge(changesetB);
changesetC.execute();

user.firstName; // "Jimmy"
user.lastName; // "Fallon"
user.address.zipCode; // "10112"

Note that both changesets A and B are not destroyed by the merge, so you might want to call destroy() on them to avoid memory leaks.

⬆️ back to top

rollback

Rolls back all unsaved changes and resets all errors.

changeset.rollback(); // returns changeset

⬆️ back to top

rollbackInvalid

Rolls back all invalid unsaved changes and resets all errors. Valid changes will be kept on the changeset.

changeset.rollbackInvalid(); // returns changeset

⬆️ back to top

rollbackProperty

Rolls back unsaved changes for the specified property only. All other changes will be kept on the changeset.

// user = { firstName: "Jim", lastName: "Bob" };
let changeset = Changeset(user);
changeset.set('firstName', 'Jimmy');
changeset.set('lastName', 'Fallon');
changeset.rollbackProperty('lastName'); // returns changeset
changeset.execute();
user.firstName; // "Jimmy"
user.lastName; // "Bob"

⬆️ back to top

validate

Validates all, single or multiple fields on the changeset. This will also validate the property on the underlying object, and is a useful method if you require the changeset to validate immediately on render.

Note: This method requires a validation map to be passed in when the changeset is first instantiated.

user.lastName = 'B';
user.address = {
  zipCode: '123'
};

let validationMap = {
  lastName: validateLength({ min: 8 }),

  // specify nested keys with dot delimiters
  'address.zipCode': validateLength({ is: 5 }),
};

let changeset = Changeset(user, validatorFn, validationMap);
changeset.get('isValid'); // true

// validate single field; returns Promise
changeset.validate('lastName');
changeset.validate('address.zipCode');
// multiple keys
changeset.validate('lastName', 'address.zipCode');

// validate all fields; returns Promise
changeset.validate().then(() => {
  changeset.get('isInvalid'); // true

  // [{ key: 'lastName', validation: 'too short', value: 'B' },
  //  { key: 'address.zipCode', validation: 'too short', value: '123' }]
  changeset.get('errors');
});

⬆️ back to top

addError

Manually add an error to the changeset.

changeset.addError('email', {
  value: '[email protected]',
  validation: 'Email already taken'
});

changeset.addError('address.zip', {
  value: '123',
  validation: 'Must be 5 digits'
});

// shortcut
changeset.addError('email', 'Email already taken');
changeset.addError('address.zip', 'Must be 5 digits');

Adding an error manually does not require any special setup. The error will be cleared if the value for the key is subsequently set to a valid value. Adding an error will overwrite any existing error or change for key.

If using the shortcut method, the value in the changeset will be used as the value for the error.

⬆️ back to top

pushErrors

Manually push errors to the changeset.

changeset.pushErrors('age', 'Too short', 'Not a valid number', 'Must be greater than 18');
changeset.pushErrors('dogYears.age', 'Too short', 'Not a valid number', 'Must be greater than 2.5');

⬆️ back to top

snapshot

Creates a snapshot of the changeset's errors and changes. This can be used to restore the changeset at a later time.

let snapshot = changeset.snapshot(); // snapshot

⬆️ back to top

restore

Restores a snapshot of changes and errors to the changeset. This overrides existing changes and errors.

let user = { name: 'Adam', address: { country: 'United States' } };
let changeset = Changeset(user, validatorFn);

changeset.set('name', 'Jim Bob');
changeset.set('address.country', 'North Korea');
let snapshot = changeset.snapshot();

changeset.set('name', 'Poteto');
changeset.set('address.country', 'Australia')

changeset.restore(snapshot);
changeset.get('name'); // "Jim Bob"
changeset.get('address.country'); // "North Korea"

⬆️ back to top

cast

Unlike Ecto.Changeset.cast, cast will take an array of allowed keys and remove unwanted keys off of the changeset.

let allowed = ['name', 'password', 'address.country'];
let changeset = Changeset(user, validatorFn);

changeset.set('name', 'Jim Bob');
changeset.set('address.country', 'United States');

changeset.set('unwantedProp', 'foo');
changeset.set('address.unwantedProp', 123);
changeset.get('unwantedProp'); // "foo"
changeset.get('address.unwantedProp'); // 123

changeset.cast(allowed); // returns changeset
changeset.get('unwantedProp'); // undefined
changeset.get('address.country'); // "United States"
changeset.get('another.unwantedProp'); // undefined

For example, this method can be used to only allow specified changes through prior to saving. This is especially useful if you also setup a schema object for your model (using Ember Data), which can then be exported and used as a list of allowed keys:

// models/user.js
export const schema = {
  name: attr('string'),
  password: attr('string')
};

export default Model.extend(schema);

// controllers/foo.js
import { schema } from '../models/user';

export default Controller.extend({
  // ...

  actions: {
    save(changeset) {
      return changeset
        .cast(Object.keys(schema))
        .save();
    }
  }
});

⬆️ back to top

isValidating

Checks to see if async validator for a given key has not resolved. If no key is provided it will check to see if any async validator is running.

changeset.set('lastName', 'Appleseed');
changeset.set('firstName', 'Johnny');
changeset.set('address.city', 'Anchorage');
changeset.validate();

changeset.isValidating(); // true if any async validation is still running
changeset.isValidating('lastName'); // true if lastName validation is async and still running
changeset.isValidating('address.city'); // true if address.city validation is async and still running

changeset.validate().then(() => {
  changeset.isValidating(); // false since validations are complete
});

back to top

beforeValidation

This event is triggered after isValidating is set to true for a key, but before the validation is complete.

changeset.on('beforeValidation', key => {
  console.log(`${key} is validating...`);
});
changeset.validate();
changeset.isValidating(); // true
// console output: lastName is validating...
// console output: address.city is validating...

⬆️ back to top

afterValidation

This event is triggered after async validations are complete and isValidating is set to false for a key.

changeset.on('afterValidation', key => {
  console.log(`${key} has completed validating`);
});
changeset.validate().then(() => {
  changeset.isValidating(); // false
  // console output: lastName has completed validating
  // console output: address.city has completed validating
});

⬆️ back to top

afterRollback

This event is triggered after a rollback of the changeset. This can be used for some advanced use cases where it is necessary to separately track all changes that are made to the changeset.

changeset.on('afterRollback', () => {
  console.log("changeset has rolled back");
});
changeset.rollback();
// console output: changeset has rolled back

⬆️ back to top

Validation signature

To use with your favorite validation library, you should create a custom validator action to be passed into the changeset:

// application/controller.js
import { action } from '@ember/object';

export default class FormController {
  @action
  validate({ key, newValue, oldValue, changes, content }) {
    // lookup a validator function on your favorite validation library
    // should return a Boolean
  }
}

{{! application/template.hbs}}
<DummyForm @changeset={{changeset model (action "validate")}} />

Your action will receive a single POJO containing the key, newValue, oldValue, a one way reference to changes, and the original object content.

Handling Server Errors

When you run changeset.save(), under the hood this executes the changeset, and then runs the save method on your original content object, passing its return value back to you. You are then free to use this result to add additional errors to the changeset via the addError method, if applicable.

For example, if you are using an Ember Data model in your route, saving the changeset will save the model. If the save rejects, Ember Data will add errors to the model for you. To copy the model errors over to your changeset, add a handler like this:

changeset.save()
  .then(() => { /* ... */ })
  .catch(() => {
    get(this, 'model.errors').forEach(({ attribute, message }) => {
      changeset.pushErrors(attribute, message);
    });
  });

Detecting Changesets

If you're uncertain whether or not you're dealing with a Changeset, you can use the isChangeset util.

import { isChangeset } from 'validated-changeset';

if (isChangeset(model)) {
  model.execute();
  // other changeset-specific code...
}

<input
  type={{type}}
  value={{get model valuePath}}
  oninput={{action (action "checkValidity" changeset) value="target.value"}}
  onblur={{action "validateProperty" changeset valuePath}}
  disabled={{disabled}}
  placeholder={{placeholder}}>

Contributors

See all the wonderful contributors who have made this library possible.

Installation

• git clone this repository
• npm install

Running Tests

• npm run test
• npm run test:all will run the current commit sha against both ember-changeset and ember-changeset-validations.

Building

• npm run build