Form

• Provided submit button
• Full example form
• Populating
• Submitting
  • Submitting via XHR/Fetch request
  • Submitting as a page request
  • Submitting forms programmatically
• Validation
  • Validation incomplete message
  • Submit invalid event
  • Validity state
• Disabling
• Resetting
  • Initial values
• Error handling
  • Form errors
  • Clearing errors
  • Input errors
• Moving validation and error messages
  • Move messages automatically
  • Move messages by node
  • FormKitMessages props
• Unmounting inputs
• Props
• Sections

While you’re free to use FormKit inputs by themselves, you’ll usually want to group them into a form. To do this, simply wrap your inputs in a <FormKit type="form">.

The form type will actively collect all the values from child inputs, using the name of each input as the property name in the resulting data object (just like groups). You can also read and write to form values using v-model just as you would on any input.

A <FormKit type="form"> tracks the form's validation state and prevents users from submitting the form if any inputs are invalid.

Provided submit button

As a convenience, the form outputs a submit button automatically, and provided themes also include a loading spinner. You can alter this button with the submit-label and submit-attrs props, or disable with :actions="false". You can pass any FormKit props to submit-attrs. In the example below, we pass classes, data attributes, help text, and even tell the included submit button to be un-ignored:

<FormKit
  type="form"
  submit-label="Update"
  :submit-attrs="{
    inputClass: 'my-input-class',
    wrapperClass: 'my-wrapper-class',
    'data-theme': `dark`,
    help: 'My button help text',
    ignore: false
  }"
></FormKit>

Full example form

Excluding backend functionality, here is a fully featured form with inputs (form, text, email, password), help text, labels, validation with custom messages, and error and submission handling:

Populating

You can populate an entire form by providing a value prop to the <FormKit type="form">. The value prop should be an object of input name to input value pairs. You may also use v-model to populate a form if you require two-way data binding:

Submitting

Forms are usually submitted through user actions like clicking a submit button or hitting the enter key on a text node within the form. Upon submission, the form (in sequence):

1. Ensures all inputs are settled (finished debouncing).
2. Emits the @submit-raw event.
3. Sets the submitted state to true on all inputs — displaying any remaining validation errors (regardless of the validation-visibility).
4. If the form has validation errors the @submit-invalid event is fired.
5. If all inputs are valid it fires the @submit event.
6. If the @submit handler returns a Promise, sets the form’s state to loading until it resolves.

Submitting via XHR/Fetch request

The most common method of form submission in a modern SPA is an XHR request (think axios or fetch). FormKit is well suited to this task:

• It hands your @submit handler 1) the collected form data as a single request-ready object (no v-model needed), and 2) the form input's core node, as a convenience.
• If you use an async submit handler, it will disable your form’s inputs and apply a loading state to your form (loading becomes true at context.state.loading and a spinner is displayed on the genesis theme).
• It handles backend errors by placing error messages directly on the failing inputs.

Submitting as a page request

To submit a form via page request, simply leave off the @submit handler. Just like native HTML, you can also provide an action and optionally a method attribute.

Submitting forms programmatically

While submitting a form using any standard HTML method is valid (like clicking a submit button, or hitting enter on a text input) — you may also submit a form programmatically. There are 2 ways to do this:

• Using this.$formkit.submit('form-id') (submitForm('form-id') for the composition api).
• Using a core node object.

Submitting with $formkit.submit()

Submitting with node.submit()

You can also submit a form programmatically by calling node.submit() on the form’s (or any input inside the form) core node. To do this you need to retrieve an instance of the core node.

Validation

Forms will not submit until all the inputs in the form are passing their validation rules.

Validation incomplete message

In addition to not firing the submit event, a message is displayed above the submit button indicating the form is still incomplete. You can customize this message using the incomplete-message prop or disable it by setting the prop to false.

Submit invalid event

When a user attempts to submit a form containing inputs that have failing validations, the @submit-invalid event is fired.

For example, we could use this event to alert our users of the failing validation rules.

Validity state

The validity of all inputs within a form is tracked automatically in the context object. This can be useful when creating various interfaces. For example, if you wanted a submit button to be disabled until all inputs are valid, you could use the state.valid property to do so.

Disabling

To disable all the inputs in a given form, including the submit button, you can use the disabled prop.

Resetting

You can reset your form (or any input) back to it’s initial state by calling $formkit.reset(formId).

Initial values

It’s important to note that the "initial state" of a form is not necessarily an empty form. You can have a default :value or v-model on the form and on individual inputs in the form — FormKit automatically merges these together to produce your initial value, and will restore to this merged state on reset.

Optionally you can provide a second argument to reset(formId, initialState) if you would prefer an alternative reset state.

Error handling

With FormKit, adding front end validation to your form is easy — but what about errors produced by your backend framework, or ones you want to manually assign? There are two types of errors you can assign to a form:

• Form errors. These are displayed at the bottom of the form above the submit button. An example would be a global message like "Sorry, our server isn’t working right now”.
• Input errors. Errors to be placed on specific inputs within your form, typically these are validation errors from your backend, like "Sorry this username is already taken".

Form errors

Form errors (ones that apply to the entire form) can be set three ways.

• Using the errors prop on a <FormKit type="form">.
• Using a core node node.setErrors().
• Using the $formkit.setErrors() Vue plugin method.

Using the errors prop

Like with any FormKit input, you can directly assign errors using the errors prop. These errors are always visible (not subject to validation-visibility).

Using node.setErrors()

Setting your form’s errors using node.setErrors is convenient since your submit handler is passed the form’s node object as its second argument. node.setErrors() takes 2 arguments — an array for form errors, and a keyed object for input errors:

Using $formkit.setErrors()

Alternatively, you can set errors directly on a form by giving the form an id and then calling $formkit.setErrors('id', ['Form error here']). The setErrors method must be passed the id of the form, and then can handle 1 or 2 additional arguments — the form errors, and the input errors:

Clearing errors

By default errors that were set on inputs using setErrors() are automatically cleared when a user changes the value of that input. You can change this default behavior by setting the preserve-errors prop.

To clear all the errors on the form (regardless of the preserve-errors prop) call node.clearErrors().

If you prefer to preserve errors by default, you can change the default behavior by modifying the preserveErrors config option. This can be done globally or for a single form:

Input errors

Input errors (ones to be displayed with specific inputs in a form) can be applied three ways:

• Manually using the errors prop on each individual input.
• Using the input-errors prop on the form (also works with groups and lists).
• Using the $formkit.setErrors() Vue plugin method (see example above).

Manually using errors prop

The most basic way to display errors on a form is using the errors prop that is available on each FormKit input.

Using input-errors prop

You can also conveniently set error messages for all inputs in your form (or group or list) using the input-errors prop. The prop accepts an object of errors, where the keys are input names (relative node addresses are supported) and the value is an error or array of errors to apply to that input.

Moving validation and error messages

By default, a form’s validation and error messages are placed directly above the form’s actions section. However, you can choose to render these anywhere on your page by using the <FormKitMessages /> component. <FormKitMessages /> is not a globally registered component — you must import it:

import { FormKitMessages } from '@formkit/vue'

There are two ways to use <FormKitMessages />:

• Automatically
• Manually by node

Move messages automatically

Place a <FormKitMessages /> component anywhere inside your form, and the form’s messages will automatically be moved to that location:

Move messages by node

To move messages anywhere in the DOM — even outside the form — you can pass the form’s core node as a prop to <FormKitMessages />. In this example, we use the messages to create a toast-style popup:

FormKitMessages props

The <FormKitMessages /> component has a few additional configuration options:

Unmounting inputs

When inputs are unmounted from a form — for example when using v-if — the key and value is removed from the form’s data. However, in some circumstances it may be preferable to keep the key/value pair even after the input has been removed. This can be accomplished by using the preserve prop:

Props

Forms are technically considered input types — so they share many of the universal props that standard inputs use.

Sections