Primitives

Form Primitives are used to compose form fields.

• Form::Label is the label associated with the form control
• Form::HelperText is an optional text used to help understand what the field is intended for
• Form::Error is the error message shown in case of failed validation of the field
• Form::Indicator is the indicator for "Required" or "Optional" inputs
• Form::Legend is the legend associated to the fieldset
• Form::Field is the generic container for control, label, helper text and error messaging
• Form::Fieldset is the generic container to group multiple fields with label, helper text, and error messaging
• Form::CharacterCount is optionally used to display the number of characters entered in a field, the maximum or minimum number of characters allowed, or a custom message communicating the relationship between the count and the maximum or minimum length.
  • CharacterCount is only used in fields that accept text values (TextInput, Textarea, MaskedInput).

We use Form Primitives as the building blocks for the “field” and “group” controls. While we recommend using our pre-defined “field” and “group” controls because they provide built-in accessibility support, you can use the Form Primitives to implement custom layouts or controls as necessary.

Content

Form::Label

• We recommend keeping labels clear and concise, about 1-3 words. They should not consist of full sentences.
• 3.2.2 Labels or Instructions (A): Labels or instructions are provided when content requires user input.

Form::HelperText

• Use helper text to give the user extra details about the data you’re asking them to input, e.g., formatting requirements such as MM-DD-YYYY.

Form::CharacterCount

Use a character count to communicate the current length of the value in an input and whether it meets or exceeds the length requirements passed to the component. The component accepts multiple arguments to set length requirements and exposes several computed values to support custom messages. Visit the code documentation for more details.

Default messages

Depending on which property (or properties) are passed to the component, a different default message will be displayed by the component to communicate the relationship between the current length of the input value (currentLength) and the maximum length (maxLength), minimum length (minLength), or both.

Test and interact with the default messaging examples in the code documentation.

The default messages provide a consistent messaging pattern for the component by clearly communicating length requirements to the user while displaying their progress towards meeting the requirements.

Usage in Figma

For representative consistency, the Figma component mirrors the default messages that are rendered in the Ember component and are labelled as such; currentLength (the default variant), maxLength, minLength, and custom.

In all variants except the custom variant, we recommend only overriding the numerical value (e.g., "{numerical value} characters is allowed"). Overriding the text in these variants will require a custom implementation on the engineering side, instead, the custom variant should be used.

Custom messages

A custom message in the character count is supported and can be used when a product or application-specific message or term is required, e.g., "registry" or "workspace".

Form::Error

• Error messages should provide the user with enough context to guide them in resolving the error.
• Keep labels and legends short and to the point (ie. "Select one option")
• Avoid overt politeness; don’t use "please" or "thank you" in your messaging.
• 3.3.1 Error Identification: If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.
• 3.3.3 Error Suggestion (AA): If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.
• 3.3.4 Error Prevention (Legal, Financial, Data) (AA): For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true: submissions are reversible, data is checked and the user is provided an opportunity to correct them, a mechanism is available for reviewing, confirming, and correcting the information before finalizing the submission.
• 4.1.3 Status Messages: In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus.

How to use this component

Form::Label

The default invocation requires text to be passed and a controlId argument (the ID of the form control associated with the label).

<Hds::Form::Label @controlId="control-ID">
  My label
</Hds::Form::Label>

Pass an isRequired argument, when user input is required for the associated form control.

<Hds::Form::Label @controlId="control-ID" @isRequired={{true}}>
  My label
</Hds::Form::Label>

Pass an isOptional argument, when the user input is optional for the associated form control.

<Hds::Form::Label @controlId="control-ID" @isOptional={{true}}>
 My label
</Hds::Form::Label>

If the label needs to contain more than just text, it’s possible to pass structured content to component. While the correct text styling is applied to the component’s container, the layout of the content inside the component is the responsibility of the product team.

<Hds::Form::Label @controlId="control-ID">
  <span>Some text</span>
  <Hds::Badge @size="small" @text="Some badge" @color="highlight" />
</Hds::Form::Label>

Form::HelperText

The default invocation requires text to be passed and a controlId argument.

The controlId value is used to generate an ID, prefixed with helper-text-, so that the ID can be referenced in the aria-describedby attribute of the form control. If no controlId is provided, no ID is generated. If needed, it can be passed directly as an HTML attribute.

<Hds::Form::HelperText @controlId="helper-text-first">
  This is some helper text
</Hds::Form::HelperText>

If the helper text needs to contain more than just text, use the block form of the component. While the correct styling is applied to the component itself, the nested components may need additional styling and are the responsibility of the product team.

<Hds::Form::HelperText @controlId="control-ID">
  Some text with a
  <Hds::Link::Inline @route="show" @model="components/link/inline">
  Hds::Link::Inline</Hds::Link::Inline>,
  or <code>some formatted code</code>
  or a <strong>strong message</strong>.
</Hds::Form::HelperText>

Form::CharacterCount

The default invocation requires a controlId argument referencing a valid <input> or <textarea> element and a @value argument storing the value of the associated form control.

The controlId value is used to generate an ID, prefixed with character-count-, so that the ID can be referenced in the aria-describedby attribute of the form control.

<input type="text" aria-label="input with default character count" id="input-character-count-default" value={{this.value1}} {{on "input" (fn this.updateValue "value1")}}/>
<Hds::Form::CharacterCount @controlId="input-character-count-default" @value={{this.value1}}/>

If the user input needs to be limited to a certain number of characters, use @maxLength to guide the user in meeting the length requirements. This property does not restrict the users from entering characters over the limit. To define the maximum string length that the user can enter, set maxlength attribute on the associated input field.

<input type="text" aria-label="input with max length count" id="input-character-count-max" value={{this.value2}} {{on "input" (fn this.updateValue "value2")}}/>
<Hds::Form::CharacterCount @maxLength={{10}} @controlId="input-character-count-max" @value={{this.value2}}/>

If the user input is required to have a certain number of characters, use @minLength to guide the user in meeting the length requirements.

<input type="text" aria-label="input with min length count" id="input-character-count-min" value={{this.value3}} {{on "input" (fn this.updateValue "value3")}}/>
<Hds::Form::CharacterCount @minLength={{3}} @controlId="input-character-count-min" @value={{this.value3}}/>

When the user input needs to be in a certain range, use both @minLength and @maxLength to guide the user in meeting the length requirements.

<input type="text" aria-label="input with min and max length count" id="input-character-count-min-max" value={{this.value4}} {{on "input" (fn this.updateValue "value4")}}/>
<Hds::Form::CharacterCount @minLength={{3}} @maxLength={{10}} @controlId="input-character-count-min-max" @value={{this.value4}}/>

Custom message

For custom messages, you can use the following arguments to build a relevant message: currentLength (the current number of characters in the associated form control), maxLength (the maximum number of characters allowed in the associated form control), minLength (the minimum number of characters required in the associated form control), remaining (the difference between maxLength and currentLength), and shortfall (the difference between currentLength and minLength).

<input type="text" aria-label="input with min and max length count" id="input-character-count-custom" value={{this.value5}} {{on "input" (fn this.updateValue "value5")}}/>
<Hds::Form::CharacterCount @maxLength={{20}} @controlId="input-character-count-custom" @value={{this.value5}} as |CC|>
  {{CC.remaining}} characters remaining
</Hds::Form::CharacterCount>

Form::Error

The default invocation requires text to be passed and a controlId argument.

The controlId value will be used to generate an ID, prefixed with error-, so that this ID can be referenced in the aria-describedby attribute of the form control. If no controlId is provided, no ID is generated. If needed, it can be passed directly as an HTML attribute.

<Hds::Form::Error @controlId="error-message-first">This is a simple error message</Hds::Form::Error>

If the error is made up of multiple messages, it’s possible to iterate over a collection of error messages.

<Hds::Form::Error @controlId="control-ID" as |Error|>
  {{#each this.SAMPLE_ERROR_MESSAGES as |message|}}
    <Error.Message>{{message}}</Error.Message>
  {{/each}}
</Hds::Form::Error>

Form::Indicator

If no isRequired/isOptional argument is provided, the component will not render anything.

Required

Pass an isRequired argument, to render a Required Indicator.

<Hds::Form::Indicator @isRequired={{true}} />

Optional

Pass an isOptional argument, to render an Optional Indicator.

<Hds::Form::Indicator @isOptional={{true}} />

Form::Legend

The default invocation requires text to be passed.

<Hds::Form::Legend>My legend</Hds::Form::Legend>

Required

Pass an isRequired argument, when user input is required for the associated form control.

<Hds::Form::Legend @isRequired={{true}}>My legend</Hds::Form::Legend>

Optional

Pass an isOptional argument, when user input is optional for the associated form control.

<Hds::Form::Legend @isOptional={{true}}>My legend</Hds::Form::Legend>

Structured content

If the legend needs to contain more than just text, it’s possible to pass structured content to component. While the correct text styling is applied to the component’s container, the layout of the content inside the component is the responsibility of the product team.

<Hds::Form::Legend>
  <span>Some text</span>
  <Hds::Badge @size="small" @text="Some badge" @color="highlight" />
</Hds::Form::Legend>

Form::Field

The default invocation includes a set of contextual components, a control (in this case a text input) with hashed values passed back to it, and a @layout argument. Depending on the context, you may want to pass just the label, or the label and the helper text, while the error message is likely conditional to the validation of the input provided by the user. The arguments id and ariaDescribedBy are automatically generated by the component and passed back to the control.

The layout of the content inside the "control" container is the responsibility of the product team.

<Hds::Form::Field @layout="vertical" @isRequired={{true}} as |F|>
  <F.Label>This is the label</F.Label>
  <F.HelperText>This is the helper text</F.HelperText>
  <F.Control>
    <!--add your control here-->
    <input
      type="email"
      id={{F.id}}
      value="jane.doe@email.com"
      class="my-custom-class"
      aria-describedby={{F.ariaDescribedBy}}
    />
  </F.Control>
  <F.Error>This is the error</F.Error>
</Hds::Form::Field>

Form::Fieldset

The default invocation includes a set of contextual components, one or more fields (in this case radio buttons within a label), and a @layout argument. Depending on the context, you may want to pass just the legend, just the helper text, both or none, while the error message is likely conditional to the validation of the inputs provided by the user.

The layout of the content inside the "control" container is the responsibility of the product team.

<Hds::Form::Fieldset @layout="horizontal" @isRequired={{true}} as |F|>
  <F.Legend>This is the legend</F.Legend>
  <F.HelperText>This is the helper text</F.HelperText>
  <!-- add your fields here -->
  <F.Control>
    <label for="my-group-checkbox1" class="my-custom-class">
      <input type="checkbox" id="my-group-checkbox1" checked="checked" />
      selection #1
    </label>
  </F.Control>
  <F.Control>
    <label for="my-group-checkbox2" class="my-custom-class">
      <input type="checkbox" id="my-group-checkbox2" />
      selection #2
    </label>
  </F.Control>
  <F.Error>This is the error</F.Error>
</Hds::Form::Fieldset>

Component API

Form::Label

Form::HelperText

Form::CharacterCount

Form::Error

Form::Indicator

Form::Legend

Form::Field

Contextual components

Control, label, helper text, and error content are passed to the field as yielded components, using the Label, HelperText, Control, CharacterCount, and Error keys.

Form::Fieldset

Contextual components

Control, Label, HelperText, and Error content are passed to the field as yielded components. The component also exposes two hashed methods, id and ariaDescribedBy.

Conformance rating

Form Primitives aren’t conformant until used in conjunction with the other components that will make them conformant.

Known issues

If a link is used within a label, helper text, or error text, it will not be presented as a link to the user with a screen reader; only the text content is read out. As such, care should be used when considering this feature.

Applicable WCAG Success Criteria

This section is for reference only, some descriptions have been truncated for brevity. This component intends to conform to the following WCAG Success Criteria:

Support

If any accessibility issues have been found within this component, let us know by submitting an issue.

4.20.0

Form::Label - Forced the for HTML attribute to be converted to a string