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Dropdown

Dropdowns allow users to select one option from a temporary modal menu.

Examples

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Code

React

Note that any undocumented props that you pass to this component will be passed to the select element, so you can use this to set additional attributes if necessary.

React Properties Documentation
NameTypeDefaultDescription
ariaLabelstring

Adds aria-label attribute. When using aria-label, label should be empty string.

classNamestring

Additional classes to be added to the root element.

childrenReact.ReactNode

Used to define custom dropdown options (i.e. option groups). When using the children prop, options should be an empty list.

defaultValuenumber | string

Sets the initial selected state. Use this for an uncontrolled component; otherwise, use the value property.

disabledboolean

Disables the entire field.

errorMessageReact.ReactNode
errorMessageClassNamestring

Additional classes to be added to the error message

errorPlacement'top' | 'bottom'

Location of the error message relative to the field input

fieldClassNamestring

Additional classes to be added to the select element

focusTriggerboolean

Used to focus select on componentDidMount()

hintReact.ReactNode

Additional hint text to display

idstring

A unique ID to be used for the dropdown field. If one isn't provided, a unique ID will be generated.

inputRef(...args: any[]) => any

Access a reference to the select element

inversedboolean

Applies the "inverse" UI theme

labelrequiredReact.ReactNode

Label for the field. If using Dropdown without a label, provide an empty string for label and use the ariaLabel prop instead.

labelClassNamestring

Additional classes to be added to the FormLabel.

namerequiredstring

The field's name attribute

optionsrequiredDropdownOptions[]

The list of options to be rendered. Provide an empty list if using custom options via the children prop.

onBlur(...args: any[]) => any
onChange(...args: any[]) => any
requirementLabelReact.ReactNode

Text showing the requirement ("Required", "Optional", etc.). See Required and Optional Fields.

size'small' | 'medium'

If the component renders a select, set the max-width of the input either to 'small' or 'medium'.

valuenumber | string

Sets the field's value. Use this in combination with onChange for a controlled component; otherwise, set defaultValue.

Styles

The following Sass variables can be overridden to customize Dropdown components:

Sass variables for dropdown
VariableDefault Core Theme Value
$dropdown__background-color$color-white
$dropdown__icon-size10px

Text Input Options

This component also makes use of some text input styles, which can be customized by the following variables:

Sass variables for text-input
VariableDefault Core Theme Value
$text-input__line-height1.3
$text-input__background-color--disabled$color-border
$text-input__border-width2px
$text-input__border-width--error3px
$text-input__border-width--success3px
$text-input__border-color$color-base
$text-input__border-color--disabled$color-gray-light
$text-input__border-color--error$color-error
$text-input__border-color--error--inverse$color-error-light
$text-input__border-color--inverse$color-black
$text-input__border-color--success$color-green-light
$text-input__color$color-base
$text-input__padding8px
$text-input__border-radius3px

Guidance

When to use

  • Use sparingly. Use the dropdown component only when a user needs to choose from about seven to 15 possible options and you have limited space to display the options.

When to consider alternatives

  • Fewer than seven options. Use radio buttons or checkboxes instead.
  • More than 15 options. If the list of options is very long. Let users type the same information into a text input that suggests possible options instead.
  • Multi-select. If you need to allow users to select more than one option at once. Users often don’t understand how to select multiple items from dropdowns. Use checkboxes instead.
  • Site navigation. Use the navigation components instead.

Usage

  • Make sure to test. Test dropdowns thoroughly with members of your target audience. Several usability experts suggest they should be the “UI of last resort.” Many users find them confusing and difficult to use.
  • Avoid dependent options. Avoid making options in one dropdown menu change based on the input to another. Users often don’t understand how selecting an item in one impacts another.
  • Use a good default. When most users will (or should) pick a particular option, make it the selected default. If a good default is not an option, use a descriptive placeholder like - Select a state - as the selected default.
  • Avoid auto-submission. Don’t use JavaScript to automatically submit the form (or do anything else) when an option is selected. Auto-submission disrupts screen readers because they select each option as they read them.

View the "Forms" guidelines for additional guidance and best practices.

Accessibility

  • Customize accessibly. If you customize the dropdown, ensure it continues to meet the the accessibility requirements that apply to all form controls.
  • Always use a label. Make sure your dropdown has a label. Don’t replace it with the default menu option (for example, removing the “State” label and just having the dropdown read “Select a state” by default).
  • Avoid auto-submission. Don’t use JavaScript to automatically submit the form (or do anything else) when an option is selected. Auto-submission disrupts screen readers because they select each option as they read them.

Learn more