Lily Design System™

Popup

A popup is a UI component that temporarily appears over the main content to convey information, prompt user actions, or display additional options without navigating away from the current screen. The Popup component provides a headless conditional dialog overlay that renders its content only when the open state is true, using proper dialog semantics for assistive technology.

The component is similar to Popover but is designed as a general-purpose overlay dialog. It uses two-way binding on the open prop, so parent components can control visibility. The consumer provides trigger elements, open/close logic, and all content.

Example

Show demo markup 
<div class="popup" role="dialog"><p>Popup content</p></div>
Usage example 
<script lang="ts">
  import Popup from './Popup.svelte';

  let open = $state(false);
</script>

<button type="button" onclick={() => (open = true)}>Delete</button>
<Popup label="Confirm deletion" bind:open>
  <p>Are you sure you want to proceed?</p>
  <button type="button" onclick={() => (open = false)}>Yes</button>
  <button type="button" onclick={() => (open = false)}>No</button>
</Popup>
Show Svelte source 
// In your Svelte component:
import Popup from "lily-design-system-svelte-headless/components/Popup/Popup.svelte";

<Popup>
  <!-- content -->
</Popup>

Usage

Quick action overlay:

<button onclick={() => showPopup = !showPopup}>Sort results</button>
<Popup label="Sort options" open={showPopup}>
  <button onclick={() => { sortBy('date'); showPopup = false; }}>Date</button>
  <button onclick={() => { sortBy('name'); showPopup = false; }}>Name</button>
  <button onclick={() => { sortBy('relevance'); showPopup = false; }}>Relevance</button>
</Popup>

Inline editing overlay:

<button onclick={() => showEdit = true}>Edit note</button>
<Popup label="Edit note" open={showEdit}>
  <textarea>{noteText}</textarea>
  <button onclick={() => { saveNote(); showEdit = false; }}>Save</button>
  <button onclick={() => showEdit = false}>Cancel</button>
</Popup>

Props

  • label: string (required) -- accessible name for the popup dialog via aria-label
  • open: boolean (default: false, bindable) -- controls whether the popup is visible; supports two-way binding
  • children: slot (required) -- the popup content rendered inside the dialog
  • ...restProps: unknown -- additional attributes spread onto the <div> element

Keyboard Interactions

  • Escape: Consumer should implement closing the popup by setting open to false
  • Tab: Should trap focus within the popup when open (consumer responsibility)

ARIA

  • role="dialog" -- identifies the popup as a dialog overlay for assistive technology
  • aria-label="..." -- provides the accessible name for the dialog

When to Use

  • Use for temporary overlay content that appears above the page, such as dropdown panels, contextual options, or quick action forms.
  • Use when the overlay does not require focus trapping or a modal backdrop -- it should allow background interaction.
  • Use when a lightweight overlay is more appropriate than a full Dialog, such as for filter panels or inline editing.

When Not to Use

  • Do not use for modal interactions requiring focus trapping -- use Dialog or AlertDialog instead.
  • Do not use for hover-triggered content -- use HoverCard or Tooltip instead.
  • Do not use for persistent side panels -- use Drawer or Sheet instead.
  • Do not use for permanent content sections -- use Panel or Card instead.

Headless

The Popup headless component provides a conditionally rendered <div> with role="dialog" and aria-label for accessible naming. It manages open/close visibility via two-way binding. The consumer provides all visual styling, positioning, trigger elements, and focus trap logic.

Styles

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

Testing

  • Verify the component renders a <div> element with class popup
  • Verify role="dialog"` -- identifies the popup as a dialog overlay for assistive technology
  • Verify aria-label="..."` -- provides the accessible name for the dialog
  • Verify keyboard interactions work correctly
  • Verify pass-through attributes are applied

Advice

  • Designers: Give popups a clear visual elevation (shadow or border) and ensure they do not cover critical page actions the user may need to reach.
  • Developers: Implement Escape key handling to close the popup, and return focus to the trigger element when the popup closes.

Implementation Notes

  • Conditionally renders a <div> with role="dialog" only when open is true
  • Supports two-way binding on the open prop
  • The label prop is required and provides the dialog's accessible name via aria-label
  • Rest props are spread onto the <div> element
  • The consumer must provide their own trigger element and manage open/close behavior
  • Content is provided via the children slot

Related components

  • popover — a floating content box anchored to a trigger element
  • tooltip — a small popup showing descriptive text on hover or focus
  • drawer — a panel that slides in from the edge of the screen

References

  • WAI-ARIA Dialog Pattern: https://www.w3.org/WAI/ARIA/apg/patterns/dialog/
  • WAI-ARIA dialog role: https://www.w3.org/TR/wai-aria-1.2/#dialog

Canonical contract

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

Metadata

  • Component: popup
  • PascalCase: Popup
  • Description: a temporary overlay that appears above page content
  • Status: stable — exercised in composed page flows under e2e and axe, beyond the per-component checks
  • HTML tag: <div>
  • CSS class: .popup
  • Interactive: yes

ARIA

  • role="dialog" -- identifies the popup as a dialog overlay for assistive technology
  • aria-label="..." -- provides the accessible name for the dialog

Keyboard

  • Escape: Consumer should implement closing the popup by setting open to false
  • Tab: Should trap focus within the popup when open (consumer responsibility)

Props

  • label: string (required) -- accessible name for the popup dialog via aria-label
  • open: boolean (default: false, bindable) -- controls whether the popup is visible; supports two-way binding
  • children: slot (required) -- the popup content rendered inside the dialog
  • ...restProps: unknown -- additional attributes spread onto the <div> element