The <sp-alert-banner> shows pressing and high-signal messages, such as system alerts. It is meant to be noticed and prompt users to take action.

yarn add @spectrum-web-components/alert-banner

Import the side effectful registration of <sp-alert-banner> via:

import '@spectrum-web-components/alert-banner/sp-alert-banner.js';

When looking to leverage the AlertBanner base class as a type and/or for extension purposes, do so via:

import { AlertBanner } from '@spectrum-web-components/alert-banner';

The alert banner accepts text context in the default slot provided:

<sp-alert-banner open>
    All documents in this folder have been archived
</sp-alert-banner>

Use the dismissible attribute to include an icon-only close button used to dismiss the alert banner:

<sp-alert-banner open dismissible>
    All documents in this folder have been archived
</sp-alert-banner>

Use the action slot for the contextual action that a user can take in response to the issue described:

<sp-alert-banner open dismissible>
    Your trial has expired
    <sp-button treatment="outline" static="white" slot="action">
        Buy now
    </sp-button>
</sp-alert-banner>

<sp-alert-banner open variant="info" dismissible>
    Your trial will expire in 3 days
    <sp-button treatment="outline" static="white" slot="action">
        Buy now
    </sp-button>
</sp-alert-banner>

<sp-alert-banner open variant="negative" dismissible>
    Connection interupted. Check your network to continue
</sp-alert-banner>

Alert banners should be used for system-level messages and they should be dismissed only as a result of a user action or if the internal state that triggered the alert has been resolved.

The alert can be dismissed by triggering the close button in case of a dismissible alert. It also exposes a public close method to allow consumers to close the alert programmatically.

The component dispatches a close event to announce that the alert banner has been closed. This can be prevented by using the event.preventDefault() API.

The sp-alert-banner element is rendered with a role of alert, to inform screen readers and notify users accordingly. When rendering an alert that is dismissable or has actions on a page, it should be placed in a container with a role of region and that region should be labelled for screen readers users to quickly navigate.

The alert banner supports keyboard interaction as follows:

• Tab should place focus on the next interactive element, which can be either the actionable button or the close button.
• Tab + Shift should place focus on the previous interactive element.
• Space or Enter should trigger the interaction if one of the buttons is focused, thus dismissing the alert in case of the close button or triggering the corresponding contextual action.
• Esc will dismiss an alert banner if it’s a dismissible alert.

Once focus is on the alert banner, arrow keys can be used to navigate between the close button and the slotted action buttons.