Lily Design System™

Notification

A notification is a UI component used to deliver timely messages to users about events, updates, or actions within an application. The Notification component provides a headless wrapper with proper ARIA live region semantics, ensuring that screen readers announce notification content when it appears. It supports both polite (non-urgent) and assertive (urgent) announcements.

The component uses role="status" with aria-live="polite" for standard notifications that wait for the user to finish their current task before being announced, and role="alert" with aria-live="assertive" for urgent notifications that interrupt the user immediately. This distinction is critical for appropriate screen reader behavior.

Example

You have new messages
Show demo markup 
<div class="notification" role="status">You have new messages</div>
Usage example 
<script lang="ts">
  import Notification from './Notification.svelte';
</script>

<Notification label="Success">Your changes have been saved.</Notification>
Show Svelte source 
// In your Svelte component:
import Notification from "lily-design-system-svelte-headless/components/Notification/Notification.svelte";

<Notification>
  <!-- content -->
</Notification>

Usage

<!-- Non-urgent notification for new messages -->
<Notification label="New messages">
  You have 3 unread messages
</Notification>

<!-- Non-urgent success notification -->
<Notification label="Success">
  Your changes have been saved.
</Notification>

<!-- Urgent session expiry warning -->
<Notification label="Session warning" urgent>
  Your session will expire in 5 minutes.
  <a href="/session/extend">Extend session</a>.
</Notification>

<!-- Urgent error notification -->
<Notification label="Error" urgent>
  Something went wrong. Please try again.
</Notification>

Props

  • label: string (optional) -- accessible name for the notification region via aria-label
  • urgent: boolean (default: false) -- when true, uses role="alert" and aria-live="assertive" instead of role="status" and aria-live="polite"
  • children: slot (required) -- the notification message content
  • ...restProps: unknown -- additional attributes spread onto the <div> element

Keyboard Interactions

None -- this component is a passive announcement container. Notifications are announced automatically by screen readers via ARIA live regions without requiring user interaction.

ARIA

  • role="status" -- applied by default for non-urgent notifications; politely announces content changes
  • role="alert" -- applied when urgent is true; assertively interrupts the user
  • aria-label="..." -- provides an accessible name for the notification region
  • aria-live="polite" -- default live region politeness; waits for user idle before announcing
  • aria-live="assertive" -- applied when urgent is true; announces immediately

When to Use

  • Use to inform users about events or updates that occurred outside their current context, such as a new message or status change
  • Use for brief, time-sensitive messages that appear temporarily and auto-dismiss
  • Use when the notification does not require immediate user action -- it is informational only
  • Use with urgent for critical messages that must immediately interrupt the user, such as errors or security alerts

When Not to Use

  • Do not use for page-level status messages -- use Banner for persistent service-wide information
  • Do not use for form validation errors -- use ErrorMessage and ErrorSummary instead
  • Do not use for critical warnings that must not be missed -- use Alert or AlertDialog for urgent messages requiring acknowledgment
  • Do not use for success confirmations on form completion -- use Banner with success variant or Panel instead

Headless

This headless component provides a <div> with ARIA live region semantics -- role="status" with aria-live="polite" by default, or role="alert" with aria-live="assertive" when urgent. The consumer provides all visual styling, including colors, icons, animations, positioning, and auto-dismiss behavior.

Styles

The consumer provides all CSS styling. The component renders with a .notification class for targeting. No default styles are included — this is a fully headless component.

Testing

  • Verify the component renders a <div> element with class notification
  • Verify role="status"` -- applied by default for non-urgent notifications; politely announces content changes
  • Verify role="alert" -- applied when urgent` is true; assertively interrupts the user
  • Verify aria-label="..."` -- provides an accessible name for the notification region
  • Verify pass-through attributes are applied

Advice

  • Designers: Use distinct visual styles for different notification types (success, error, warning, info) and ensure notifications do not obscure important page content.
  • Developers: Use the urgent prop only for messages requiring immediate attention. Polite notifications wait for the user to finish their current task before being announced.

Implementation Notes

  • Renders a <div> element with a live region role
  • Uses role="status" and aria-live="polite" by default for non-urgent notifications
  • When urgent is true, switches to role="alert" and aria-live="assertive"
  • The label prop provides an accessible name via aria-label
  • Content is provided via the children slot
  • Rest props are spread onto the <div> element

Related components

  • toast — a brief auto-dismissing notification message
  • alert — a status message for important information or feedback
  • banner — a prominent message bar across the top of a page

References

  • WAI-ARIA alert role: https://www.w3.org/TR/wai-aria-1.2/#alert
  • WAI-ARIA status role: https://www.w3.org/TR/wai-aria-1.2/#status
  • WAI-ARIA Live Regions: https://www.w3.org/WAI/ARIA/apd/practices/live-regions/

Canonical contract

Generated from this component's canonical metadata — the machine-checked source the implementations are held to.

Metadata

  • Component: notification
  • PascalCase: Notification
  • Description: a brief message about an event or update
  • Status: stable — exercised in composed page flows under e2e and axe, beyond the per-component checks
  • HTML tag: <div>
  • CSS class: .notification
  • Interactive: no

ARIA

  • role="status" -- applied by default for non-urgent notifications; politely announces content changes
  • role="alert" -- applied when urgent is true; assertively interrupts the user
  • aria-label="..." -- provides an accessible name for the notification region
  • aria-live="polite" -- default live region politeness; waits for user idle before announcing
  • aria-live="assertive" -- applied when urgent is true; announces immediately

Keyboard

  • No keyboard interactions — this is a passive element

Props

  • label: string (optional) -- accessible name for the notification region via aria-label
  • urgent: boolean (default: false) -- when true, uses role="alert" and aria-live="assertive" instead of role="status" and aria-live="polite"
  • children: slot (required) -- the notification message content
  • ...restProps: unknown -- additional attributes spread onto the <div> element