Discourse toolkit to render forms

system · September 13, 2024, 9:20pm

Basic Usage

FormKit exposes a single component as its public API: <Form />. All other elements are yielded as contextual components, modifiers, or plain data.

Every form is composed of one or multiple fields, representing the value, validation, and metadata of a control. Each field encapsulates a control, which is the form element the user interacts with to enter data, such as an input or select. The control type is specified via @type on the field. Other utilities, like submit or alert, are also provided.

Here is the most basic example of a form:

import Component from "@glimmer/component";
import { action } from "@ember/object";
import Form from "discourse/components/form";

export default class MyForm extends Component {
  @action
  handleSubmit(data) {
    // do something with data
  }

  <template>
    <Form @onSubmit={{this.handleSubmit}} as |form|>
      <form.Field
        @name="username"
        @title="Username"
        @validation="required"
        @type="input"
        as |field|
      >
        <field.Control />
      </form.Field>

      <form.Field @name="age" @title="Age" @type="input-number" as |field|>
        <field.Control />
      </form.Field>

      <form.Submit />
    </Form>
  </template>
}

Form

Yielded Parameters

form

The Form component yields a form object containing contextual components and helper functions.

Common members include:

Field, Object, Collection, Fieldset, Row, Section, Container
Submit, Reset, Button, Alert, Actions
CheckboxGroup, InputGroup, ConditionalContent
set(name, value), setProperties(object), addItemToCollection(name, value)

Example

<Form as |form|>
  <form.Row as |row|>
    <!-- ... -->
  </form.Row>
</Form>

transientData

transientData is the form’s current draft state. It starts as a clone of @data, updates as the user edits fields, and does not mutate the original @data object.

This is useful if you want to have conditionals in your form based on other fields.

Example

<Form as |form transientData|>
  <form.Field @name="amount" @title="Amount" @type="input-number" as |field|>
    <field.Control />
  </form.Field>

  {{#if (gt transientData.amount 200)}}
    <form.Field @name="confirmed" @title="Confirm" @type="checkbox" as |field|>
      <field.Control>I know what I'm doing</field.Control>
    </form.Field>
  {{/if}}
</Form>

Arguments

@data

Initial state of the form data.

FormKit expects a plain JavaScript object (POJO). Internally it clones that object into draft state, tracks patches, and only mutates its own internal copy.

Keys matching field @names are prepopulated automatically, including nested object and collection paths.

@data is treated as immutable. Edits do not mutate the original object you pass in. If you need to keep some external state in sync while editing, do that explicitly in @onSet.

When deriving a form object from a model, prefer a cached getter:

@cached
get formData() {
  return getProperties(this.model, "foo", "bar", "baz");
}

Parameter

data (Object): The data object passed to the template.

Example

<Form @data={{hash foo="bar"}} as |form|>
  <form.Field @name="foo" @title="Foo" @type="input" as |field|>
    <!-- This input will have "bar" as its initial value -->
    <field.Control />
  </form.Field>
</Form>

@onRegisterApi

Callback called when the form instance is created. It allows the developer to interact with the form through JavaScript.

Parameters

callback (Object): The object containing callback functions.
callback.get (Function): Returns the current value for a field name.
callback.submit (Function): Function to submit the form.
callback.reset (Function): Function to reset the form.
callback.set (Function): Function to set a key/value on the form data object.
callback.setProperties (Function): Function to set an object on the form data object.
callback.addError (Function): Function to add an error programmatically.
callback.removeError (Function): Function to remove a single field error.
callback.removeErrors (Function): Function to clear all errors.
callback.isDirty (boolean): Tracked property exposing the dirty state of the form. It becomes true after changes are made and returns to false after reset.

Example

registerAPI({ get, submit, reset, set, addError }) {
  // Interact with the form API
  get("foo");
  submit();
  reset();
  set("foo", 1);
  addError("foo", { title: "Foo", message: "Something went wrong" });
}

<Form @onRegisterApi={{this.registerAPI}} />

@onSubmit

Callback called when the form is submitted and valid.

Parameters

data (Object): The current draft data for the form.

Example

handleSubmit({ username, age }) {
  console.log(username, age);
}

<Form @onSubmit={{this.handleSubmit}} as |form|>
  <form.Field @name="username" @title="Username" @type="input" as |field|>
    <field.Control />
  </form.Field>
  <form.Field @name="age" @title="Age" @type="input-number" as |field|>
    <field.Control />
  </form.Field>
  <form.Submit />
</Form>

@onReset

Callback called after FormKit rolls the draft data back to its initial state and clears errors.

Parameters

data (Object): The rolled-back draft data.

Example

handleReset(data) {
  console.log("reset to", data);
}

<Form @data={{this.formData}} @onReset={{this.handleReset}} as |form|>
  <form.Field @name="username" @title="Username" @type="input" as |field|>
    <field.Control />
  </form.Field>

  <form.Reset />
</Form>

@validate

A custom validation callback added directly to the form. This runs once per validation pass, after field-level validation.

Example

@action
myValidation(data, { addError }) {
  if (data.foo !== data.bar) {
    addError("foo", { title: "Foo", message: "Bar must be equal to Foo" });
  }
}

<Form @validate={{this.myValidation}} />

An asynchronous example:

@action
async myValidation(data, { addError }) {
  try {
    await ajax("/check-username", {
      type: "POST",
      data: { username: data.username }
    });
  } catch(e) {
    addError("username", { title: "Username", message: "Already taken!" });
  }
}

@validateOn

Controls when FormKit should validate.

Accepted values: submit (default), change, focusout, and input.

Example

<Form @validateOn="change" />

@onDirtyCheck

Callback used during route transitions when the form is dirty. Return a truthy value to show the built-in “dirty form” confirmation dialog, or a falsy value to skip it.

Parameters

transition (Transition): The Ember route transition being processed.

Example

@action
onDirtyCheck(transition) {
  return transition.to?.name !== "wizard.step";
}

<Form @onDirtyCheck={{this.onDirtyCheck}} />

Field

@name

A field must have a unique name. This name is used to read/write the value on the form data object and is also used for validation.

Names cannot contain . or -. Dots are reserved for nested paths such as profile.location.city.

Example

<form.Field @name="foo" @title="Foo" @type="input" as |field|>
  <field.Control />
</form.Field>

@title

A field must have a title. It will be displayed above the control and is also used in validation.

Example

<form.Field @name="foo" @title="Foo" @type="input" as |field|>
  <field.Control />
</form.Field>

@type

A field must have a type. This determines which control component is rendered. The available types are:

Input types: input (defaults to text), input-text, input-number, input-email, input-password, input-url, input-tel, input-date, input-time, input-datetime-local, input-color, input-month, input-week, input-range, input-search, input-hidden
Other controls: checkbox, code, calendar, color, composer, custom, emoji, icon, image, menu, password, question, radio-group, select, tag-chooser, textarea, toggle

Example

<form.Field @name="foo" @title="Foo" @type="input" as |field|>
  <field.Control />
</form.Field>

@description

The description is optional and will be shown under the title when set.

Example

<form.Field
  @name="foo"
  @title="Foo"
  @description="Bar"
  @type="input"
  as |field|
>
  <field.Control />
</form.Field>

@helpText

The help text is optional and will be shown under the field when set.

Example

<form.Field @name="foo" @title="Foo" @helpText="Baz" @type="input" as |field|>
  <field.Control />
</form.Field>

@showTitle

By default, the title will be shown on top of the control. You can choose not to render it by setting this property to false.

Example

<form.Field
  @name="foo"
  @title="Foo"
  @showTitle={{false}}
  @type="input"
  as |field|
>
  <field.Control />
</form.Field>

@disabled

A field can be disabled to prevent any changes to it.

Example

<form.Field
  @name="foo"
  @title="Foo"
  @disabled={{true}}
  @type="input"
  as |field|
>
  <field.Control />
</form.Field>

@tooltip

Allows to display a tooltip next to the field’s title. Won’t display if title is not shown.
You can pass a string or a <DTooltip /> component.

Example

<Form as |form|>
  <form.Field
    @name="foo"
    @title="Foo"
    @type="input"
    @tooltip="a nice input"
    as |field|
  >
    <field.Control />
  </form.Field>
</Form>

<Form as |form|>
  <form.Field
    @name="foo"
    @title="Foo"
    @type="input"
    @tooltip={{component DTooltip content="a nice input"}}
    as |field|
  >
    <field.Control />
  </form.Field>
</Form>

@validation

Read the dedicated validation section.

@validate

Read the dedicated custom validation section.

@onSet

By default, when changing the value of a field, this value will be set on the form’s internal data object. However, you can choose to have full control over this process for a field.

Example

@action
handleFooChange(value, { set, name, parentName, index }) {
  set("foo", value + "-bar");
}

<form.Field
  @name="foo"
  @title="Foo"
  @type="input"
  @onSet={{this.handleFooChange}}
  as |field|
>
  <field.Control />
</form.Field>

You can use @onSet to also mutate the initial data object if you need more reactivity for a specific case.

The second argument passed to @onSet contains:

set(name, value): update form draft state
name: the field’s full name
parentName: the parent path for nested fields
index: the current collection index when inside a collection

Example

@action
handleFooChange(value, { set }) {
  set("foo", value + "-bar");
  this.model.foo = value + "-bar";
}

<Form @data={{this.model}} as |form|>
  <form.Field
    @name="foo"
    @title="Foo"
    @type="input"
    @onSet={{this.handleFooChange}}
    as |field|
  >
    <field.Control />
  </form.Field>
</Form>

Yielded Parameters

The field yields a single field object. The control component determined by @type is available as field.Control.

<form.Field @name="foo" @title="Foo" @type="input" as |field|>
  <field.Control />
</form.Field>

field.Control

field.Control is the control component determined by @type. You can pass control-specific attributes directly to it (e.g., @height, @lang, placeholder).

field.Control is the supported API. Older yielded names such as field.Input are deprecated.

field

The yielded field object provides access to the field’s data and helpers:

Name	Description
`Control`	Contextual component for the control set by `@type`
`id`	ID to be used on the control for accessibility
`errorId`	ID of the field error container
`name`	Full field name, including nested path prefixes
`value`	Current value from draft data
`set`	Function to set the field’s value

Controls

Controls, as we use the term here, refer to the UI widgets that allow a user to enter data. In its most basic form, this would be an input. The control type is specified via @type on the field.

You can pass down HTML attributes to the underlying control.

Example

<Form as |form|>
  <form.Field
    @name="query"
    @title="Query"
    @type="input"
    @description="You should make sure the query doesn't include bots."
    as |field|
  >
    <field.Control placeholder="Foo" />
  </form.Field>
</Form>

@format

Controls accept a @format property which can be: small, medium, large, or full.

Form Kit sets defaults for each control, but you can override them using @format:

small: 100px
medium: 220px
large: 400px
full: 100%

Additionally, the following CSS variables are provided to customize these defaults:

small: --form-kit-small-input
medium: --form-kit-medium-input
large: --form-kit-large-input

@titleFormat

Allows to override @format for the title. See @format for details.

@descriptionFormat

Allows to override @format for the description. See @format for details.

Checkbox

Renders an <input type="checkbox"> element.

When to use a single checkbox
There are only 2 options: yes/no. It feels like agreeing to something. Checking the box doesn’t save; there is a submit button further down.

Example

<Form as |form|>
  <form.Field @name="approved" @title="Approved" @type="checkbox" as |field|>
    <field.Control />
  </form.Field>
</Form>

Calendar

Renders a datepicker and a time input. On mobile the datepicker will be replaced by a date input.

@includeTime

Displays the time input or not. Defaults to true.

Example

<Form as |form|>
  <form.Field @name="start" @title="Start" @type="calendar" as |field|>
    <field.Control @includeTime={{false}} />
  </form.Field>
</Form>

@expandedDatePickerOnDesktop

Displays date picker expanded on desktop. Defaults to true.

Example

<Form as |form|>
  <form.Field @name="start" @title="Start" @type="calendar" as |field|>
    <field.Control @expandedDatePickerOnDesktop={{false}} />
  </form.Field>
</Form>

Code

Renders an <AceEditor /> component.

@height

Sets the height of the editor in pixels.

@lang

Sets the editor mode.

Example

<Form as |form|>
  <form.Field @name="query" @title="Query" @type="code" as |field|>
    <field.Control @lang="sql" @height={{400}} />
  </form.Field>
</Form>

Color

Renders a color input with optional preset swatches.

Common control arguments:

@colors: array of preset colors
@usedColors: array of already-used colors
@collapseSwatches: collapse swatches into a menu
@collapseSwatchesLabel: label for the collapsed swatches button
@allowNamedColors: allow named colors instead of only hex values
@fallbackValue: value to restore on blur when left blank

Example

<Form as |form|>
  <form.Field @name="color" @title="Color" @type="color" as |field|>
    <field.Control
      @colors={{array "0088CC" "FFCC00"}}
      @usedColors={{array "FFCC00"}}
    />
  </form.Field>
</Form>

Composer

Renders a <DEditor /> component.

@height

Sets the height of the composer.

Example

<Form as |form|>
  <form.Field @name="message" @title="Message" @type="composer" as |field|>
    <field.Control @height={{400}} />
  </form.Field>
</Form>

@preview

Controls the display the composer preview. Defaults to false.

Example

<Form as |form|>
  <form.Field @name="message" @title="Message" @type="composer" as |field|>
    <field.Control @preview={{true}} />
  </form.Field>
</Form>

Custom

Renders a wrapper for custom content. This is the right choice when you want to provide your own control markup but still use FormKit field metadata and state.

Example

<Form as |form|>
  <form.Field @name="slug" @title="Slug" @type="custom" as |field|>
    <field.Control>
      <MyCustomControl
        id={{field.id}}
        @value={{field.value}}
        @onChange={{field.set}}
      />
    </field.Control>
  </form.Field>
</Form>

Emoji

Renders an <EmojiPicker /> component.

@context

Passes the picker context through to <EmojiPicker />.

Example

<Form as |form|>
  <form.Field @name="emoji" @title="Emoji" @type="emoji" as |field|>
    <field.Control @context="chat" />
  </form.Field>
</Form>

Icon

Renders an <IconPicker /> component.

Example

<Form as |form|>
  <form.Field @name="icon" @title="Icon" @type="icon" as |field|>
    <field.Control />
  </form.Field>
</Form>

Image

Renders an <UppyImageUploader /> component.

Common control arguments:

@type: uploader context passed to <UppyImageUploader />
@placeholderUrl: optional placeholder image

Upload Handling

By default, the component will set an upload object. It’s common to only want the URL and the ID of the upload. To achieve this, you can use the @onSet property on the field:

@action
handleUpload(upload, { set }) {
  set("upload_id", upload.id);
  set("upload_url", getURL(upload.url));
}

<Form as |form|>
  <form.Field
    @name="upload"
    @title="Upload"
    @type="image"
    @onSet={{this.handleUpload}}
    as |field|
  >
    <field.Control />
  </form.Field>
</Form>

Example

<Form as |form|>
  <form.Field @name="upload" @title="Upload" @type="image" as |field|>
    <field.Control />
  </form.Field>
</Form>

Input

Renders an <input> element.

@type

The input variant is specified as part of the field’s @type using the input- prefix. For example, @type="input", @type="input-number", or @type="input-email". @type="input" defaults to text.

Allowed Types

input (defaults to text)
input-color
input-date
input-datetime-local
input-email
input-hidden
input-month
input-number
input-password
input-range
input-search
input-tel
input-text
input-time
input-url
input-week

Special Cases

checkbox and radio have dedicated controls
file uploads should use @type="image"

Examples

<Form as |form|>
  <form.Field @name="email" @title="Email" @type="input" as |field|>
    <field.Control />
  </form.Field>

  <form.Field @name="age" @title="Age" @type="input-number" as |field|>
    <field.Control />
  </form.Field>
</Form>

@before

Renders text before the input

Examples

<Form as |form|>
  <form.Field @name="email" @title="Email" @type="input" as |field|>
    <field.Control @before="mailto:" />
  </form.Field>
</Form>

@after

Renders text after the input

Examples

<Form as |form|>
  <form.Field @name="email" @title="Email" @type="input" as |field|>
    <field.Control @after=".com" />
  </form.Field>
</Form>

<Form as |form|>
  <form.Field @name="email" @title="Email" @type="menu" as |field|>
    <field.Control as |menu|>
      <menu.Item @value={{1}} @icon="pencil-alt">Edit</menu.Item>
      <menu.Divider />
      <menu.Container class="foo">
        Bar
      </menu.Container>
      <menu.Item @action={{this.doSomething}}>Something</menu.Item>
    </field.Control>
  </form.Field>
</Form>

Password

Renders a password input with a visibility toggle.

This is different from @type="input-password". The dedicated password control adds the show/hide button.

Example

<Form as |form|>
  <form.Field @name="secret" @title="Secret" @type="password" as |field|>
    <field.Control />
  </form.Field>
</Form>

Question

Renders two inputs of type radio where the first one is a positive answer, the second one a negative answer.

@yesLabel

Allows to customize the positive label.

@noLabel

Allows to customize the negative label.

Examples

<Form as |form|>
  <form.Field @name="email" @title="Email" @type="question" as |field|>
    <field.Control @yesLabel="Correct" @noLabel="Wrong" />
  </form.Field>
</Form>

RadioGroup

Renders a list of radio buttons sharing a common name.

Example

<Form as |form|>
  <form.Field @name="foo" @title="Foo" @type="radio-group" as |field|>
    <field.Control as |radioGroup|>
      <radioGroup.Radio @value="one">One</radioGroup.Radio>
      <radioGroup.Radio @value="two">Two</radioGroup.Radio>
      <radioGroup.Radio @value="three">Three</radioGroup.Radio>
    </field.Control>
  </form.Field>
</Form>

Radio yielded parameters

Title

Allows to render a title.

Examples

<Form as |form|>
  <form.Field @name="foo" @title="Foo" @type="radio-group" as |field|>
    <field.Control as |RadioGroup|>
      <RadioGroup.Radio @value="one" as |radio|>
        <radio.Title>One title</radio.Title>
      </RadioGroup.Radio>
    </field.Control>
  </form.Field>
</Form>

Description

Allows to render a description.

Examples

<Form as |form|>
  <form.Field @name="foo" @title="Foo" @type="radio-group" as |field|>
    <field.Control as |RadioGroup|>
      <RadioGroup.Radio @value="one" as |radio|>
        <radio.Description>One description</radio.Description>
      </RadioGroup.Radio>
    </field.Control>
  </form.Field>
</Form>

Select

Renders a <DSelect /> component.

@includeNone

By default, Select includes a “none” option when the field is blank or when the field is not marked required. Override this with @includeNone.

Example

<Form as |form|>
  <form.Field @name="fruits" @title="Fruits" @type="select" as |field|>
    <field.Control as |select|>
      <select.Option @value="1">Mango</select.Option>
      <select.Option @value="2">Apple</select.Option>
      <select.Option @value="3">Coconut</select.Option>
    </field.Control>
  </form.Field>
</Form>

Tag Chooser

Renders a <TagChooser /> component.

Common control arguments:

@allowCreate
@categoryId
@showAllTags
@excludeSynonyms
@excludeTagsWithSynonyms
@unlimited
@placeholder

Example

<Form as |form|>
  <form.Field @name="tags" @title="Tags" @type="tag-chooser" as |field|>
    <field.Control @categoryId={{1}} @allowCreate={{true}} />
  </form.Field>
</Form>

Textarea

Renders a <textarea> element.

@height

Sets the height of the textarea.

Example

<Form as |form|>
  <form.Field
    @name="description"
    @title="Description"
    @type="textarea"
    as |field|
  >
    <field.Control @height={{120}} />
  </form.Field>
</Form>

Toggle

Renders a <DToggleSwitch /> component.

There are only 2 states: enabled/disabled. It should feel like turning something on. Toggling takes effect immediately, there is no submit button.

Example

<Form as |form|>
  <form.Field @name="allowed" @title="Allowed" @type="toggle" as |field|>
    <field.Control />
  </form.Field>
</Form>

Layout

Form Kit aims to provide good defaults, allowing you to mainly use fields and controls. However, if you need more control, we provide several helpers: Row and Col, Section, Fieldset, Container and Actions.

You can also use utilities like Submit, Reset, Alert, CheckboxGroup, InputGroup, and ConditionalContent.

Actions

Actions is a custom Container designed to wrap your buttons in the footer of your form.

Example

<Form as |form|>
  <form.Actions>
    <form.Submit />
  </form.Actions>
</Form>

Alert

Displays an alert in the form.

@icon

An optional icon to use in the alert.

Example

<form.Alert @icon="info-circle">
  Foo
</form.Alert>

@type

Specifies the type of alert. Allowed types: success, error, warning, or info.

Example

<form.Alert @type="warning">
  Foo
</form.Alert>

Checkbox Group

CheckboxGroup allows grouping checkboxes together.

Example

<form.CheckboxGroup @title="Preferences" as |group|>
  <group.Field @name="editable" @title="Editable" @type="checkbox" as |field|>
    <field.Control />
  </group.Field>
  <group.Field
    @name="searchable"
    @title="Searchable"
    @type="checkbox"
    as |field|
  >
    <field.Control />
  </group.Field>
</form.CheckboxGroup>

ConditionalContent

ConditionalContent helps you switch between mutually exclusive blocks of content using a small radio control.

Example

<Form as |form|>
  <form.ConditionalContent @activeName="basic" as |conditional|>
    <conditional.Conditions as |Condition|>
      <Condition @name="basic">Basic</Condition>
      <Condition @name="advanced">Advanced</Condition>
    </conditional.Conditions>

    <conditional.Contents as |Content|>
      <Content @name="basic">
        <form.Alert>Basic settings</form.Alert>
      </Content>

      <Content @name="advanced">
        <form.Alert @type="warning">Advanced settings</form.Alert>
      </Content>
    </conditional.Contents>
  </form.ConditionalContent>
</Form>

Container

Container allows you to render a block similar to a field without tying it to specific data. It is useful for custom controls.

Common arguments:

@title
@subtitle
@format
@direction

Example

<Form as |form|>
  <form.Container @title="Important" @subtitle="This is important">
    <!-- Container content here -->
  </form.Container>
</Form>

Fieldset

Wraps content in a fieldset.

Example

<form.Fieldset @name="a-fieldset" class="my-fieldset">
  Foo
</form.Fieldset>

@title

Displays a title for the fieldset, will use the legend element.

Example

<form.Fieldset @title="A title">
  Foo
</form.Fieldset>

@description

Displays a description for the fieldset.

Example

<form.Fieldset @description="A description">
  Foo
</form.Fieldset>

@name

Sets the name of the fieldset. This is necessary if you want to use the fieldset test helpers.

Example

<form.Fieldset @name="a-name">
  Foo
</form.Fieldset>

Input Group

Input group allows you to group multiple inputs together on one line.

Example

<Form as |form|>
  <form.InputGroup as |inputGroup|>
    <inputGroup.Field @title="Foo" @name="foo" @type="input" as |field|>
      <field.Control />
    </inputGroup.Field>
    <inputGroup.Field @title="Bar" @name="bar" @type="input" as |field|>
      <field.Control />
    </inputGroup.Field>
  </form.InputGroup>
</Form>

Reset

The Reset component renders a <DButton /> which will reset the form when clicked. It accepts all the same parameters as a standard <DButton />. The label and default action are set by default.

Example

<form.Reset />

To customize the Reset button further, you can pass additional parameters as needed:

Example with Additional Parameters

<form.Reset @translatedLabel="Remove changes" />

Row and Col

Row and Col enable you to utilize a simple grid system (12 columns) within your form.

Example

<Form as |form|>
  <form.Row as |row|>
    <row.Col @size={{4}}>
      <form.Field @name="foo" @title="Foo" @type="input" as |field|>
        <field.Control />
      </form.Field>
    </row.Col>
    <row.Col @size={{8}}>
      <form.Field @name="bar" @title="Bar" @type="input" as |field|>
        <field.Control />
      </form.Field>
    </row.Col>
  </form.Row>
</Form>

Section

Section provides a simple way to create a section with or without a title.

@subtitle

Displays secondary text in the section header.

Example

<Form as |form|>
  <form.Section @title="Settings">
    <!-- Section content here -->
  </form.Section>
</Form>

Submit

The Submit component renders a <DButton /> which will submit the form when clicked. It accepts all the same parameters as a standard <DButton />. The label, default action, and primary style are set by default.

Example

<form.Submit />

To customize the Submit button further, you can pass additional parameters as needed:

Example with Additional Parameters

<form.Submit @translatedLabel="Send" />

Object

The object component lets you work with a nested object in your form.

Example

<Form @data={{hash foo=(hash bar=1 baz=2)}} as |form|>
  <form.Object @name="foo" as |object data|>
    <object.Field @name="bar" @title="Bar" @type="input" as |field|>
      <field.Control />
    </object.Field>
    <object.Field @name="baz" @title="Baz" @type="input" as |field|>
      <field.Control />
    </object.Field>
  </form.Object>
</Form>

@name

An object must have a unique name. This name is used as a prefix for the underlying fields.

Like field names, object names should not contain . or -.

Example

<form.Object @name="foo" />

Nesting

An object can accept a nested Object or Collection.

Example

<Form @data={{hash foo=(hash bar=(hash baz=1 bol=2))}} as |form|>
  <form.Object @name="foo" as |parentObject|>
    <parentObject.Object @name="bar" as |childObject data|>
      <childObject.Field @name="baz" @title="Baz" @type="input" as |field|>
        <field.Control />
      </childObject.Field>
    </parentObject.Object>
  </form.Object>
</Form>

<Form @data={{hash foo=(hash bar=(array 1 2))}} as |form|>
  <form.Object @name="foo" as |parentObject|>
    <parentObject.Collection @name="bar" as |collection index|>
      <collection.Field @title="Baz" @type="input" as |field|>
        <field.Control />
      </collection.Field>
      <form.Button
        class={{concat "remove-" index}}
        @action={{fn collection.remove index}}
      >Remove</form.Button>
    </parentObject.Collection>
  </form.Object>
</Form>

Collection

The collection component lets you work with arrays in your form.

It yields three values: the collection API, the current index, and the current item.

Example

<Form @data={{hash foo=(array (hash bar=1) (hash bar=2))}} as |form|>
  <form.Collection @name="foo" as |collection index item|>
    <collection.Field @name="bar" @title="Bar" @type="input" as |field|>
      <field.Control placeholder={{concat "item-" index}} />
    </collection.Field>
  </form.Collection>
</Form>

@name

A collection must have a unique name. This name is used as a prefix for the underlying fields.

For example, if collection has the name “foo”, the 2nd field of the collection with the name “bar”, will actually have “foo.1.bar” as name.

Like field names, collection names should not contain . or -.

Example

<form.Collection @name="foo" />

@tagName

A collection renders as a <div class="form-kit__collection"> by default. You can alter this behavior with @tagName.

Example

<form.Collection @name="foo" @tagName="tr" />

Primitive array

If the shape of your data is an array of primitives, eg: [1, 2, 3], form-kit is able to handle it. You just have to omit the name on the field in this case, as the name will be auto generated for you with the index.

Example

<Form @data={{hash foo=(array 1 2)}} as |form|>
  <form.Collection @name="foo" as |collection|>
    <collection.Field @title="Baz" @type="input" as |field|>
      <field.Control />
    </collection.Field>
  </form.Collection>
</Form>

Nesting

A collection can accept a nested Object or Collection.

Example

<Form
  @data={{hash foo=(array (hash bar=(hash baz=1)) (hash bar=(hash baz=2)))}}
  as |form|
>
  <form.Collection @name="foo" as |collection|>
    <collection.Object @name="bar" as |object|>
      <object.Field @name="baz" @title="Baz" @type="input" as |field|>
        <field.Control />
      </object.Field>
    </collection.Object>
  </form.Collection>
</Form>

<Form
  @data={{hash
    foo=(array (hash bar=(array (hash baz=1))) (hash bar=(array (hash baz=2))))
  }}
  as |form|
>
  <form.Collection @name="foo" as |parent parentIndex|>
    <parent.Collection @name="bar" as |child childIndex|>
      <child.Field @name="baz" @title="Baz" @type="input" as |field|>
        <field.Control />
      </child.Field>
    </parent.Collection>
  </form.Collection>
</Form>

Add an item to the collection

The <Form /> component yielded object has a addItemToCollection function that you can call to add an item to a specific collection.

Example

<Form @data={{hash foo=(array (hash bar=1) (hash bar=2))}} as |form|>
  <form.Button @action={{fn form.addItemToCollection "foo" (hash bar=3)}}>
    Add
  </form.Button>

  <form.Collection @name="foo" as |collection index|>
    <collection.Field @name="bar" @title="Bar" @type="input" as |field|>
      <field.Control placeholder={{concat "item-" index}} />
    </collection.Field>
  </form.Collection>
</Form>

Remove an item from the collection

The <Collection /> component yielded object has a remove function that you can call to remove an item from this collection, it takes the index as parameter

Example

<Form @data={{hash foo=(array (hash bar=1) (hash bar=2))}} as |form|>
  <form.Collection @name="foo" as |collection index|>
    <collection.Field @name="bar" @title="Bar" @type="input" as |field|>
      <field.Control />
      <form.Button @action={{fn collection.remove index}}>
        Remove
      </form.Button>
    </collection.Field>
  </form.Collection>
</Form>

Validation

Field accepts a @validation property which allows you to describe the validation rules of the field.

List of Available Rules

Accepted

The value must be "yes", "on", true, 1, or "true". Useful for checkbox inputs — often where you need to validate if someone has accepted terms.

Example

<form.Field
  @name="terms"
  @title="Terms"
  @type="checkbox"
  @validation="accepted"
  as |field|
>
  <field.Control />
</form.Field>

Between

Checks that a numeric value is between a minimum and maximum value.

Example

<form.Field
  @name="amount"
  @title="Amount"
  @type="input-number"
  @validation="between:1,10"
  as |field|
>
  <field.Control />
</form.Field>

dateAfterOrEqual

Checks if a calendar value is after or equal to the specified date. Format must be YYYY-MM-DD.

Example

<form.Field
  @name="start"
  @title="Start"
  @type="calendar"
  @validation="dateAfterOrEqual:2022-02-01"
  as |field|
>
  <field.Control />
</form.Field>

dateBeforeOrEqual

Checks if a calendar value is before or equal to the specified date. Format must be YYYY-MM-DD.

Example

<form.Field
  @name="start"
  @title="Start"
  @type="calendar"
  @validation="dateBeforeOrEqual:2022-02-01"
  as |field|
>
  <field.Control />
</form.Field>

EndsWith

Checks that a string ends with a given suffix.

Example

<form.Field
  @name="domain"
  @title="Domain"
  @type="input"
  @validation="endsWith:.com"
  as |field|
>
  <field.Control />
</form.Field>

Integer

Checks if the value is an integer.

Example

<form.Field
  @name="age"
  @title="Age"
  @type="input-number"
  @validation="integer"
  as |field|
>
  <field.Control />
</form.Field>

Length

Checks that the input’s value is over a given length, or between two length values.

Example

<form.Field
  @name="username"
  @title="Username"
  @type="input"
  @validation="length:5,16"
  as |field|
>
  <field.Control />
</form.Field>

Number

Checks if the input is a valid number as evaluated by isNaN().

When applicable, prefer to use the number input: @type="input-number".

Example

<form.Field
  @name="amount"
  @title="Amount"
  @type="input"
  @validation="number"
  as |field|
>
  <field.Control />
</form.Field>

Required

Checks if the input is empty.

required:trim trims leading and trailing whitespace before checking the value.

Example

<form.Field
  @name="username"
  @title="Username"
  @type="input"
  @validation="required:trim"
  as |field|
>
  <field.Control />
</form.Field>

StartsWith

Checks that a string starts with a given prefix.

Example

<form.Field
  @name="handle"
  @title="Handle"
  @type="input"
  @validation="startsWith:@"
  as |field|
>
  <field.Control />
</form.Field>

URL

Checks if the input value appears to be a properly formatted URL including the protocol. This does not check if the URL actually resolves.

Example

<form.Field
  @name="endpoint"
  @title="Endpoint"
  @type="input-url"
  @validation="url"
  as |field|
>
  <field.Control />
</form.Field>

Combining Rules

Rules can be combined using the pipe operator: |.

Example

<form.Field
  @name="username"
  @title="Username"
  @type="input"
  @validation="required|length:5,16"
  as |field|
>
  <field.Control />
</form.Field>

Custom Validation

Field

Field accepts a @validate property which allows you to define a callback function to validate a single field.

Parameters

name (string): The name of the form field being validated.
value (unknown): The current field value.
context (Object)
- context.data (Object): Current form draft data.
- context.type (string): Field control type.
- context.addError (Function): Adds an error if validation fails.

Example

@action
validateUsername(name, value, { data, addError }) {
  if (value === data.slug) {
    addError(name, {
      title: "Username",
      message: "Username and slug must differ.",
    });
  }
}

<form.Field
  @name="username"
  @title="Username"
  @type="input"
  @validate={{this.validateUsername}}
  as |field|
>
  <field.Control />
</form.Field>

Form

Form accepts a @validate property which allows you to define a callback function to validate the full form state once per validation pass.

Parameters

data (Object): The data object containing additional information for validation.
handlers (Object): An object containing handler functions.
- handlers.addError (Function): A function to add an error if validation fails.
- handlers.removeError (Function): A function to clear an existing error.

Example

@action
validateForm(data, { addError, removeError }) {
  if (data.start && data.end && data.end < data.start) {
    addError("end", {
      title: "End",
      message: "End must be after start.",
    });
  } else {
    removeError("end");
  }
}

<Form @validate={{this.validateForm}} as |form|>
  <form.Field @name="start" @title="Start" @type="input-date" as |field|>
    <field.Control />
  </form.Field>

  <form.Field @name="end" @title="End" @type="input-date" as |field|>
    <field.Control />
  </form.Field>

  <form.Submit />
</Form>

Unknown validation rule names raise at runtime. Keep the rule list above in sync with the implementation when extending FormKit.

Helpers

Helpers are yielded by some blocks, like Form, or provided as parameters to callbacks. They allow you to interact with the form state in a simple and clear way.

set

set allows you to assign a value to a specific field in the form’s data.

Parameters

name (string): The name of the field to which the value is to be set.
value (number): The value to be set.

Example

set("foo", 1);

Using the set helper yielded by the form:

<Form as |form|>
  <DButton @action={{fn form.set "foo" 1}} @translatedLabel="Set foo" />
</Form>

setProperties

setProperties allows you to assign an object to the form’s data.

Parameters

data (object): A POJO where each key is going to be set on the form using its value.

Example

setProperties({ foo: 1, bar: 2 });

Using the setProperties helper yielded by the form:

<Form as |form|>
  <DButton
    @action={{fn form.setProperties (hash foo=1 bar=2)}}
    @translatedLabel="Set foo and bar"
  />
</Form>

addError

addError allows you to add an error message to a specific field in the form.

Parameters

name (string): The name of the field that is invalid.
error (object): The error’s data
- title (string): The title of the error, usually the translated name of the field
- message (string): The error message

Example

addError("foo", { title: "Foo", message: "This should be another thing." });

Customize

Plugin Outlets

FormKit works seamlessly with <PluginOutlet />. You can use plugin outlets inside your form to extend its functionality:

<Form as |form|>
  <PluginOutlet @name="above-foo-form" @outletArgs={{hash form=form}} />
</Form>

Then, in your connector, you can use the outlet arguments to add custom fields:

<@outletArgs.form.Field @name="bar" @title="Bar" @type="input" as |field|>
  <field.Control />
</@outletArgs.form.Field>

Styling

All FormKit components propagate attributes, allowing you to set classes and data attributes, for example:

<Form class="my-form" as |form|>
  <form.Field
    @name="foo"
    @title="Foo"
    @type="input"
    class="my-field"
    as |field|
  >
    <field.Control class="my-control" />
  </form.Field>
</Form>

Custom Control

Creating a custom control is straightforward with the properties yielded by form and field:

<Form as |form|>
  <form.Field
    @name="foo"
    @title="Foo"
    @type="custom"
    class="my-field"
    as |field|
  >
    <field.Control>
      <MyCustomControl id={{field.id}} @onChange={{field.set}} />
    </field.Control>
  </form.Field>
</Form>

Common Values on `form`

Name	Description
`set`	Set any field by name, e.g. `set("bar", 1)`
`setProperties`	Set multiple field values at once
`addItemToCollection`	Append an item to a collection by path

Common Values on `field`

Name	Description
`id`	Input ID
`errorId`	Error container ID
`name`	Full nested field path
`value`	Current field value from draft state
`set`	Set the current field value

Javascript assertions

Form

The form element assertions are available at assert.form(...).*. By default it will select the first “form” element.

Parameters

target (string | HTMLElement): The form element or selector.

hasErrors()

Asserts that the form error summary contains the given field errors.

Parameters

fields (Object): A map of field names to error messages, e.g. { username: "Required" }.
message (string) [optional]: The description of the test.

Example

assert.form().hasErrors({ username: "Required" }, "the form shows errors");

hasNoErrors()

Asserts that the form error summary is not present.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().hasNoErrors("the form is valid");

Field

The field element assertions are available at assert.form(...).field(...).*.

Parameters

name (string): The name of the field.

Example

assert.form().field("foo");

hasValue()

Asserts that the value of the field matches the expected text.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasValue("bar", "user has set the value");

hasNoValue()

Asserts that the field is blank.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasNoValue("the field starts blank");

isDisabled()

Asserts that the field is disabled.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").isDisabled("the field is disabled");

isEnabled()

Asserts that the field is enabled.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").isEnabled("the field is enabled");

hasTitle()

Asserts that the field title matches the expected text.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasTitle("Foo", "it shows the field title");

hasDescription()

Asserts that the field description matches the expected text.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert
  .form()
  .field("foo")
  .hasDescription("Helpful copy", "it shows the description");

hasError()

Asserts that the field has a specific error.

Parameters

error (string): The error message on the field.
message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasError("Required", "it is required");

hasNoErrors()

Asserts that the field has no error.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasNoErrors("it is valid");

exists()

Asserts that the field is present.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").exists("it has the foo field");

doesNotExist()

Asserts that the field is not present.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().field("foo").doesNotExist("it has no foo field");

hasCharCounter()

Asserts that the field has a char counter.

Parameters

current (integer): The current length of the field.
max (integer): The max length of the field.
message (string) [optional]: The description of the test.

Example

assert.form().field("foo").hasCharCounter(2, 5, "it has updated the counter");

Fieldset

The field element assertions are available at assert.form(...).fieldset(...).*.

Parameters

name (string): The name of the fieldset.

Example

assert.form().fieldset("foo");

hasTitle()

Asserts that the title of the fieldset matches the expected value.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert.form().fieldset("foo").hasTitle("bar", "it has the correct title");

hasDescription()

Asserts that the description of the fieldset matches the expected value.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert
  .form()
  .fieldset("foo")
  .hasDescription("bar", "it has the correct description");

includesText()

Asserts that the fieldset has yielded the expected value.

Parameters

expected (anything): The expected value.
message (string) [optional]: The description of the test.

Example

assert.form().fieldset("foo").includesText("bar", "it has the correct text");

exists()

Asserts that the fieldset is present.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().fieldset("foo").exists("the fieldset is rendered");

doesNotExist()

Asserts that the fieldset is not present.

Parameters

message (string) [optional]: The description of the test.

Example

assert.form().fieldset("foo").doesNotExist("the fieldset is hidden");

Javascript helpers

Form

The FormKit helper allows you to manipulate a form and its fields through a clear and expressive API.

Example

import formKit from "discourse/tests/helpers/form-kit-helper";

test("fill in input", async function (assert) {
  await render(
    <template>
      <Form class="my-form" as |form data|>
        <form.Field @name="foo" @title="Foo" @type="input" as |field|>
          <field.Control />
        </form.Field>
      </Form>
    </template>
  );

  const myForm = formKit(".my-form");
});

submit()

Submits the associated form.

Example

formKit().submit();

reset()

Resets the associated form.

Example

formKit().reset();

field()

Returns a field helper for a named field.

Parameters

name (string): The name of the field.

Example

const field = formKit().field("foo");

hasField()

Checks whether a field with the given name exists in the form.

Parameters

name (string): The name of the field.

Example

formKit().hasField("foo");

Field

Parameters

name (string): The name of the field.

value()

Returns the current UI value for supported controls.

Example

formKit().field("foo").value();

options()

Returns the available option values for a @type="select" field.

Example

formKit().field("foo").options();

fillIn()

Can be used on input-like controls such as @type="input", @type="input-text", @type="input-number", @type="password", @type="color", @type="code", @type="textarea", and @type="composer".

Parameters

value (string | integer | undefined): The value to set on the input.

Example

await formKit().field("foo").fillIn("bar");

toggle()

Can be used on @type="checkbox", @type="toggle", or @type="password" fields.

Will toggle the state of the control. In the case of the password control it will actually toggle the visibility of the field.

Example

await formKit().field("foo").toggle();

accept()

Can be used on @type="question" fields.

Example

await formKit().field("foo").accept();

refuse()

Can be used on @type="question" fields.

Example

await formKit().field("foo").refuse();

select()

Can be used on @type="select", @type="menu", @type="icon", @type="radio-group", and @type="color" fields.

Will select the given value.

Parameters

value (string | integer | undefined): The value to select.

Example

await formKit().field("foo").select("bar");

setDay()

Can be used on @type="calendar" fields.

Parameters

day (integer): The day of the month to select.

Example

await formKit().field("start").setDay(15);

setTime()

Can be used on @type="calendar" fields.

Parameters

time (string): The time to set, e.g. "14:30".

Example

await formKit().field("start").setTime("14:30");

isDisabled()

Returns whether the field is disabled.

Example

formKit().field("foo").isDisabled();

hasPrefix()

Can be used on @type="color" fields. Returns whether the color input renders its prefix.

Example

formKit().field("color").hasPrefix();

swatches()

Can be used on @type="color" fields. Returns the rendered swatches as { color, isUsed, isDisabled }.

Example

formKit().field("color").swatches();

triggerEvent()

Triggers a DOM event on the field’s input element.

Parameters

eventName (string): The event to trigger.
options (Object) [optional]: Extra event options.

Example

await formKit().field("foo").triggerEvent("blur");

System specs page object

Form

The FormKit page object component is available to help you write system specs for your forms.

Parameters

target (string): The selector of the form.

Example

form = PageObjects::Components::FormKit.new(".my-form")

submit

Submits the form.

Example

form.submit

reset

Resets the form.

Example

form.reset

has_an_alert?

Checks whether the form renders an alert with the given message.

Example

form.has_an_alert?("message")

expect(form).to have_an_alert("message")

has_field_with_name?

Checks whether a field with the given data-name exists.

Example

form.has_field_with_name?("foo")

has_no_field_with_name?

Checks whether a field with the given data-name is absent.

Example

form.has_no_field_with_name?("foo")

container

Returns a container helper for the named container.

Example

container = form.container("advanced-settings")
container.has_content?("More options")

choose_conditional

Chooses a ConditionalContent branch by radio value.

Example

form.choose_conditional("advanced")

Field

The field helper allows you to interact with a specific field of a form.

Parameters

name (string): The name of the field.

Example

field = form.field("foo")

value

Returns the value of the field.

Example

field.value

expect(field).to have_value("bar")

has_value?

Checks that the field value matches the expected value.

Example

field.has_value?("bar")

checked?

Returns if the control of a checkbox is checked or not.

Example

field.checked?

expect(field).to be_checked

unchecked?

Returns if the control of a checkbox is unchecked or not.

Example

field.unchecked?

expect(field).to be_unchecked

disabled?

Returns if the field is disabled or not.

Example

field.disabled?

expect(field).to be_disabled

enabled?

Returns if the field is enabled or not.

Example

field.enabled?

expect(field).to be_enabled

toggle

Allows toggling a field. Available for @type="checkbox", @type="password", and @type="toggle".

Example

field.toggle

fill_in

Allows filling a field with a given value. Available for @type="input", @type="input-*" variants, @type="password", @type="color", @type="textarea", @type="code", and @type="composer".

Example

field.fill_in("bar")

select

Allows selecting a specified value in a field. Available for @type="select", @type="icon", @type="menu", @type="radio-group", @type="question", tag choosers, and custom multi-select controls.

Example

field.select("bar")

accept

Allows accepting a field. Only available for: @type="question".

Example

field.accept

refuse

Allows refusing a field. Only available for: @type="question".

Example

field.refuse

upload_image

Takes an image path on the filesystem and uploads it for the field. Only available for the @type="image" control.

Example

field.upload_image(image_file_path)

has_errors?

Checks that the field renders the given error messages.

Example

field.has_errors?("Required")

has_no_errors?

Checks that the field has no errors.

Example

field.has_no_errors?

has_selected_names?

Checks the selected names for a @type="tag-chooser" field.

Example

field.has_selected_names?("support", "meta")

This document is version controlled - suggest changes on github.

pfaffman · September 22, 2024, 9:34pm

system:

validateUsername(name, value, data, { addError }) {
  if (data.bar / 2 === value) {
    addError(name, { title: I18n.t(`foo.bar.${name}`), message: "That's not how maths work." });
  }
}

The above code won’t work. This code does:

  validateApiKeyValue(name, value, { data, addError }) {
    console.log(`validate ${name} with ${value}`, data);
  }

Is the documentation wrong or is the code wrong?

EDIT: I decided that it is, Update 21-form-kit.md by pfaffman · Pull Request #62 · discourse/discourse-developer-docs · GitHub

NateDhaliwal · December 7, 2024, 2:25am

I think all the @ stuff should be in backticks. It curently pings users with the same usernames.

awesomerobot · January 23, 2025, 7:41pm

I think the Form import was wrong, so I’ve updated OP

from

import Form from "discourse/form";

to

import Form from "discourse/components/form";

pfaffman · January 23, 2025, 7:51pm

Do I understand correctly that is this now the Recommended Way to create a form to, say, collect data for a new model added by a plugin? Or is this for something else?

A quick glance at the core source shows no few examples outside of tests and all of them–including those I see in official plugins–are in /admin

This plugin is adding a decidedly non-forum-like model to Discourse (Discourse is my only tool, so anything I develop on the web is likely to be a Discourse plugin). Can I assume that it does make sense to use this toolkit for all my forms?

awesomerobot · January 23, 2025, 8:28pm

Yes, that’s the intent… if all forms use the same patterns they’re easier for us to support along with future updates

pfaffman · January 23, 2025, 8:33pm

That makes sense, and One Day, Core and Official Plugins will switch to using it so I’ll have more examples?

And no one has done much of that yet since the code all works without using this wonderous new template?

Thanks for your patience! I spent at least an hour debugging this plugin because it wasn’t enabled, so I’m feeling pretty unsure of anything right now.

pfaffman · January 31, 2025, 5:26pm

Can you also edit the example code, which is what people like me paste blindly into their editors?

I tried to edit it, but got an error about mentioning more than 10 users.

pfaffman · January 31, 2025, 11:22pm

I’ve made headway over the past couple days trying to make this work. I feel like I’m the first person to try to follow these instructions. Here are some things that hung me up. I think a full working example, either as a gist or maybe something in core would be a big help. But, I’ve now got it working!

Maybe move transientData down below as it’s not always needed, and a bunch of stuff that hasn’t been introduced at that point is always needed to have a working example?

Similarly, I don’t understand how to use formData() in that example. Other than declaring it, it’s never used. Maybe you’d called it like data = formData() Or you’d pass it as <Form @data=this.formData ...?

Talking about validation doesn’t make sense until we actually know what fields are

Except it won’t work (if you want it to use any data?) without (as far as I can tell) if you doln’t

But you can’t do that without

import { cached, tracked } from "@glimmer/tracking";

Or maybe you don’t have to do that, but you do have to include @data={{@somethign}} in the <Form> tag? (That at least got the data to display in the form.

No. Textarea renders a textarea as shown in the example below.

I can’t get the DEditor to show the preview pane. I’m pretty sure that I was seeing it when I tried making a DEditor as a custom field.

Arkshine · February 1, 2025, 12:17am

I’m using it in an upcoming TC; however, it’s just the basic stuff.

I agree that the documentation could be more precise. I also struggled, mainly because the explanations and examples were sometimes confusing. I think it’s more about the order in which things are explained in the issue. Also, in the examples, the declaration of an array with hash confused me initially for some reasons.

That said, it’s really cool stuff, and having a normalized way to make form is excellent!

I don’t know if it will help you, but here is what I essentially did (kept only the essentials)

import Component from "@glimmer/component";
import { cached, tracked } from "@glimmer/tracking";

const FORM_FIELDS = ["title", "maxWidth", "autoFit", "duration"];

export default class OptionsMarkmap extends Component {
  @tracked data;

  constructor() {
    super(...arguments);

    // Sets the default values
    this.data = {
      title: "",
      maxWidth: 0
      autoFit: "true"
      duration: 400,
    };
  }

  @cached
  get formData() {
    return getProperties(this.data, ...FORM_FIELDS);
  }

  @action
  save(data) {
    // 
  }

  <template>
    <Form @data={{this.formData}} @onSubmit={{this.save}} as |form|>
      <form.Field
        @name="title"
        @title="Title"
        @format="large"
        as |field|
      >
        <form.Container>
          <field.Input />
        </form.Container>
      </form.Field>

      <form.Field
        @name="maxWidth"
        @title="Max Node Width"
        @type="number"
        as |field|
      >
        <form.Container>
          <field.Input />
        </form.Container>
      </form.Field>

      <form.Field
        @name="autoFit"
        @showTitle={{false}}
        @title="Auto Fit"
        as |field|
      >
        <form.Container>
          <field.Checkbox />
        </form.Container>
      </form.Field>

      <form.Actions>
        <form.Submit @label="Save" />
      </form.Actions>
    </Form>
  </template>
}

About data, this is your initial value.
The use of formData allows you to cache the object (since data is immutable), and getProperties is a nice way to specify what fields you include, I believe. formData is what you provide in <Form @data=....

get formData() {
  return getProperties(this.data, ...FORM_FIELDS);
}

pfaffman · February 2, 2025, 7:47pm

Yeah. That all makes sense, but mostly only once you know!

But I think I don’t understand what’s getting cached, or maybe where or why?

Ah! That’s nice.

Yes. I think that’s looking like a much better “minimal working model”!

Thanks!

And more about `field.Composer`

~~I still can’t figure out how to get it to show the preview.~~I got some CSS to make the preview show, but I still can’t make it take up the full width.

I’ve got <field.Composer @height={{80}} /> and it looks exactly the same as <field.Composer @height={{800}} />, (maybe there is some default CSS that’s overriding this?)–found it! --form-kit-large-input: 100%; (actually that affects the width, but I’m still not sure about the height)

j.jaffeux · February 3, 2025, 10:49am

There are full working examples in core FTR.

j.jaffeux · February 3, 2025, 11:56am

There were legit issues on this. I fixed them all in FIX: supports height/preview form-kit composer by jjaffeux · Pull Request #31121 · discourse/discourse · GitHub and documented in document composer preview option by jjaffeux · Pull Request #37 · discourse/discourse-developer-docs · GitHub

pfaffman · February 3, 2025, 1:18pm

There weren’t (many?) last I looked. Either I was bad at grep last time, or a whole bunch have been added in the past week or two. It’d be great if this documentation pointed to one of them that’s a good exemplar.

Dude! That’s awesome! I can’t wait to check it out. I spent (what felt like) all day yesterday on this (at least 2 hours, though). I’m so horrible at CSS I assumed I was just boneheaded. Ah, you fixed the hidden and height parts. It’s the width that I’m struggling with now. I can’t get the composer to take up half the screen and instead it takes up more space as text gets typed in, and if the field is empty it’s so small that there’s nowhere to type text. I’ll take a look later, but I’m so excited I wanted to respond ASAP.

j.jaffeux · February 3, 2025, 1:19pm

@format="full" on the field wrapping the composer

david · February 3, 2025, 1:29pm

Try this search - it has at least 10 ‘real’ examples, and also a bunch of examples in tests.

j.jaffeux · February 3, 2025, 1:57pm

Yep, and honestly Im reluctant to link to examples from docs as these links tend to age badly as people won’t know the doc is linking to it if they remove the file, change the path, …

pfaffman · February 3, 2025, 8:01pm

Indeed you did! It’s really working!

Thanks so very much.

merefield · March 27, 2025, 1:43pm

What’s the right way to implement a “Multi” Select? ie whereby I can offer the user the ability to update an array from a constant set of enums.

I guess I could use a Checkbox Group

But is there a “dropdown” flavour?

for example if I have some ingredients:

[“rice”, “mango”, “egg”, “salt”, “cumin”]

and I want the user to be able to select none, one, many or all.

And the result should be stored in a single array.

ie a toggle for each member of the full set.

Is there an existing example of this?

Arkshine · March 27, 2025, 4:11pm

Maybe use a custom field along side with MultiSelect? https://meta.discourse.org/t/discourse-toolkit-to-render-forms/326439#p-1603904-custom-control-110

I see some examples in core, for example:

<form.Field
    @name="appliesTo"
    @title={{i18n "admin.config_areas.flags.form.applies_to"}}
    @validation="required"
    @validate={{this.validateAppliesTo}}
    @format="large"
    as |field|
  >
    <field.Custom>
      <MultiSelect
        @id={{field.id}}
        @value={{field.value}}
        @onChange={{field.set}}
        @content={{this.appliesToValues}}
        @options={{hash allowAny=false}}
        class="admin-flag-form__applies-to"
      />
    </field.Custom>
  </form.Field>

Would it that work for you?

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Discourse toolkit to render forms

Basic Usage

Form

Yielded Parameters

form

transientData

Arguments

@data

@onRegisterApi

@onSubmit

@onReset

@validate

@validateOn

@onDirtyCheck

Field

@name

@title

@type

@description

@helpText

@showTitle

@disabled

@tooltip

@validation

@validate

@onSet

Yielded Parameters

field.Control

field

Controls

@format

@titleFormat

@descriptionFormat

Checkbox

Calendar

@includeTime

@expandedDatePickerOnDesktop

Code

@height

@lang

Color

Composer

@height

@preview

Custom

Emoji

@context

Icon

Image

Upload Handling

Input

@type

Allowed Types

Special Cases

@before

@after

Menu

@selection

yielded parameters

Item

Divider

Container

Password

Question

@yesLabel

@noLabel

RadioGroup

Radio yielded parameters

Title

Description

Select

@includeNone

Tag Chooser

Textarea

@height

Toggle

Layout

Actions

Alert

@icon

Common Values on `form`

Common Values on `field`