2nd/10_Wiki/Topics/Backend/Accordion.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-accordion	Accordion	10_Wiki/Topics	verified	self	Collapsible Disclosure	none	A	0.9	applied	ui component a11y		2026-05-10	pending	language framework TypeScript React

Accordion

매 한 줄

"매 expand-on-demand UI primitive". 매 1980s desktop GUI 의 origin → 매 2026 web 의 ARIA disclosure pattern, FAQ/sidebar/settings 의 default density-saving widget.

매 핵심

매 mechanism

• 매 header (button) + 매 panel (region) 의 pair.
• 매 aria-expanded + aria-controls + region role 의 a11y triplet.
• 매 single-expand (radio-like) vs multi-expand (checkbox-like).

매 modern stack

• 매 Radix UI Accordion (headless, WAI-ARIA-compliant).
• 매 React Aria, Headless UI, shadcn/ui Accordion.
• 매 native <details>/<summary> (free a11y, limited animation).

매 응용

1. FAQ pages (Stripe, GitHub docs).
2. Settings panels (VSCode sidebar).
3. Mobile navigation drawers.

💻 패턴

Radix UI Accordion (single-expand)

import * as Accordion from '@radix-ui/react-accordion';

export function FAQ() {
  return (
    <Accordion.Root type="single" collapsible defaultValue="item-1">
      <Accordion.Item value="item-1">
        <Accordion.Trigger className="flex w-full justify-between p-4">
          What is React?
          <ChevronDown className="transition-transform data-[state=open]:rotate-180" />
        </Accordion.Trigger>
        <Accordion.Content className="overflow-hidden data-[state=open]:animate-slideDown">
          A library for UIs.
        </Accordion.Content>
      </Accordion.Item>
    </Accordion.Root>
  );
}

Native <details> (zero-JS)

<details>
  <summary>Click to expand</summary>
  <p>Hidden content.</p>
</details>

<style>
  details[open] summary ~ * { animation: slideDown 200ms ease-out; }
  @keyframes slideDown { from { opacity: 0; transform: translateY(-8px); } }
</style>

Custom hook (multi-expand)

function useAccordion(initial: string[] = []) {
  const [open, setOpen] = useState(new Set(initial));
  const toggle = (id: string) =>
    setOpen(prev => {
      const next = new Set(prev);
      next.has(id) ? next.delete(id) : next.add(id);
      return next;
    });
  return { isOpen: (id: string) => open.has(id), toggle };
}

매 height animation (interpolate to auto)

[data-state='closed'] { grid-template-rows: 0fr; }
[data-state='open']   { grid-template-rows: 1fr; }
.panel { display: grid; transition: grid-template-rows 200ms; }
.panel > div { overflow: hidden; }

매 keyboard support (Radix-equivalent)

function onKeyDown(e: KeyboardEvent) {
  if (e.key === 'ArrowDown') focusNextHeader();
  if (e.key === 'ArrowUp')   focusPrevHeader();
  if (e.key === 'Home')      focusFirstHeader();
  if (e.key === 'End')       focusLastHeader();
}

매 결정 기준

상황	Approach
0-JS, simple FAQ	<details>
Animated, controlled	Radix UI
Form section	Custom (preserve mounted state)

기본값: Radix UI Accordion + Tailwind animations.

🔗 Graph

• 부모: Disclosure-Pattern · Headless-UI
• 변형: Collapsible · Tabs
• 응용: FAQ · Settings-Panel
• Adjacent: Radix-UI · ARIA

🤖 LLM 활용

언제: density-saving long-form lists, optional sections. 언제 X: critical information (hidden by default = missed); sequential workflows (use Stepper).

❌ 안티패턴

• Multi-open by default 의 visual chaos: Use single-expand for nav.
• No aria-expanded: screen readers 매 broken.
• Animating height: auto: Use grid-rows trick or max-height.

🧪 검증 / 중복

• Verified (Radix UI docs, WAI-ARIA Accordion Pattern).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — Accordion FULL content with Radix patterns