Combobox

lightning-combobox

A widget that provides an input field that is readonly, accompanied by a dropdown list of selectable options.

For Use In

Lightning Experience, Experience Builder Sites, Salesforce Mobile App, Lightning Out (Beta), Standalone Lightning App, Mobile Offline

lightning-combobox is an input element that enables single selection from a list of options. The result of the selection is stored as the value of the input. Multiple selection is currently not supported. To support multiple selection, use lightning-dual-listbox instead.

This component implements the combobox blueprint in the Salesforce Lightning Design System.

This example creates a list of options with a default selection that's specified with the value attribute. The options attribute specifies the name of an array of items for the dropdown list.

In your JavaScript, define an array of options. Each option corresponds to a list item on the dropdown list. Define the content of each option by specifying a value property and a label property. The label value is displayed for the item in the rendered dropdown list, while the value property's value is stored when the item is selected.

Define an optional description property to add a line of descriptive text for each option. The descriptive text displays below the label of the list item. When adding descriptions, specify a description for each item in a list. If some items are missing descriptions, the text of the items can be misaligned.

Selecting an option triggers the change event, which calls the handleChange function. To check which option has been clicked, use event.detail.value.

Client-side input validation is available for this component. You can make the selection required by adding the required attribute. An error message is automatically displayed when an item is not selected and the element is required.

To check the validity states of an input, use the validity attribute, which is based on the ValidityState object. You can access the validity states in your Javascript. This validity attribute returns an object with boolean attributes. See lightning-input for more information.

You can override the default message by providing your own value for message-when-value-missing.

Special characters like " must be escaped. For example, you want to display "New".

When using single quotes in your value, escape the quote with a double slash instead of a single slash.

lightning-combobox doesn't currently support autocomplete or typeahead. The autocomplete attribute is reserved for internal use.

In Lightning Experience, a lightning-combobox dropdown list that's opened overlays the record edit page or modal, the global header, and record form footer when scrolling.

On mobile devices, lightning-combobox has the following limitations.

  • The dropdown menu doesn't scroll correctly when there isn't enough room to display the complete list of options.
  • The mobile viewport doesn't display the dropdown menu correctly especially if the component is placed near the bottom of the page.

We recommend using the HTML <select> element on mobile instead.

You must provide a text label for accessibility to make the information available to assistive technology. The label attribute creates an HTML label element for your component. To hide a label from view and make it available to assistive technology, use the label-hidden variant.

This component uses button elements for select-only comboboxes to comply with the Lightning Design System combobox blueprint.

When an option label is too long to fit in a single line, the label wraps and continues in a new line. If a long word in an option label isn't fully visible, scroll horizontally on the dropdown list to reveal the whole word.

change

The event fired when an item is selected in the combobox.

The change event returns the following parameter.

ParameterTypeDescription
selectedValuestringThe value of the selected option.

The event properties are as follows.

PropertyValueDescription
bubblestrueThis event bubbles up through the DOM.
cancelablefalseThis event has no default behavior that can be canceled. You can't call preventDefault() on this event.
composedtrueThis event propagates outside of the component in which it was dispatched.

open

The event fired when the dropdown is opened.

The open event does not return any parameters.

PropertyValueDescription
bubblesfalseThis event does not bubble.
cancelablefalseThis event has no default behavior that can be canceled. You cannot call preventDefault() on this event.
composedfalseThis event does not propagate outside of the component in which it was dispatched.

Component styling hooks use the --slds-c-* prefix and change styling for specific elements or properties of a component. Component-specific styling isn’t recommended, because it’s unsupported for SLDS 2, but existing customizations still work with the original SLDS. If you use component styling hooks, limit the components to SLDS themes until SLDS 2 and the Salesforce Cosmos theme become generally available. See Combobox: Styling Hooks Overview for documentation on component-specific hooks for this component.

For more information, see Style Components Using Lightning Design System Styling Hooks in the Lightning Web Components Developer Guide.