Interaction Patterns

Interaction Patterns

Codifiable UI interaction patterns that prevent common UX failures. Covers loading states, content pagination, disclosure patterns, overlays, drag-and-drop, tab overflow, and notification systems — all with accessibility baked in.

Quick Reference

Total: 10 rules across 6 categories

Decision Table — Loading States

Quick Start

Skeleton Loading

function CardSkeleton() {
  return (
    <div className="animate-pulse space-y-3">
      <div className="h-48 w-full rounded-lg bg-muted" />
      <div className="h-4 w-3/4 rounded bg-muted" />
      <div className="h-4 w-1/2 rounded bg-muted" />
    </div>
  )
}

function CardList({ items, isLoading }: { items: Item[]; isLoading: boolean }) {
  if (isLoading) {
    return (
      <div className="grid grid-cols-3 gap-4">
        {Array.from({ length: 6 }).map((_, i) => (
          <CardSkeleton key={i} />
        ))}
      </div>
    )
  }
  return (
    <div className="grid grid-cols-3 gap-4">
      {items.map((item) => <Card key={item.id} item={item} />)}
    </div>
  )
}

Infinite Scroll with Accessibility

function InfiniteList({ fetchNextPage, hasNextPage, items }: Props) {
  const sentinelRef = useRef<HTMLDivElement>(null)

  useEffect(() => {
    const observer = new IntersectionObserver(
      ([entry]) => { if (entry.isIntersecting && hasNextPage) fetchNextPage() },
      { rootMargin: "200px" }
    )
    if (sentinelRef.current) observer.observe(sentinelRef.current)
    return () => observer.disconnect()
  }, [fetchNextPage, hasNextPage])

  return (
    <div role="feed" aria-busy={isFetching}>
      {items.map((item) => (
        <article key={item.id} aria-posinset={item.index} aria-setsize={-1}>
          <ItemCard item={item} />
        </article>
      ))}
      <div ref={sentinelRef} />
      {hasNextPage && (
        <button => fetchNextPage()}>Load more items</button>
      )}
      <div aria-live="polite" className="sr-only">
        {`Showing ${items.length} items`}
      </div>
    </div>
  )
}

Rule Details

Skeleton Loading

Content-shaped placeholders that match the final layout. Use skeleton for lists, cards, and text blocks.

Load: rules/interaction-skeleton-loading.md

Infinite Scroll

Accessible infinite scroll with IntersectionObserver, screen reader announcements, and "Load more" fallback.

Load: rules/interaction-infinite-scroll.md

Progressive Disclosure

Reveal complexity progressively: tooltip, accordion, wizard, contextual panel.

Load: rules/interaction-progressive-disclosure.md

Modal / Drawer / Inline

Choose the right overlay pattern: modal for confirmations, drawer for detail views, inline for simple toggles.

Load: rules/interaction-modal-drawer-inline.md

Drag & Drop

Drag-and-drop with mandatory keyboard alternatives using @dnd-kit/core.

Load: rules/interaction-drag-drop.md

Tabs Overflow

Scrollable tab bars with overflow menus for dynamic or numerous tabs.

Load: rules/interaction-tabs-overflow.md

Toast Notifications

Positioned, auto-dismissing notifications with ARIA roles and stacking.

Load: rules/interaction-toast-notifications.md

Cognitive Load Thresholds

Miller's Law (max 7 items per group), Hick's Law (max 1 primary CTA), and Doherty Threshold (400ms feedback) with specific, countable limits.

Load: rules/interaction-cognitive-load-thresholds.md

Form UX

Fitts's Law touch targets (44px mobile), top-aligned labels, Poka-Yoke error prevention with blur-only validation, and smart defaults.

Load: rules/interaction-form-ux.md

Persuasion Ethics

13 dark pattern red flags to detect and reject, the Hook Model ethical test (aware, reversible, user-benefits), and EU DSA Art. 25 compliance.

Load: rules/interaction-persuasion-ethics.md

Key Principles

1. Keyboard parity — Every mouse interaction MUST have a keyboard equivalent. No drag-only, no hover-only.
2. Skeleton over spinner — Use content-shaped placeholders for data loading; reserve spinners for indeterminate actions.
3. Native HTML first — Prefer <dialog>, <details>, role="feed" over custom implementations.
4. Progressive enhancement — Features should work without JS where possible, then enhance with interaction.
5. Announce state changes — Use aria-live regions to announce dynamic content changes to screen readers.
6. Respect scroll position — Back navigation must restore scroll position; infinite scroll must not lose user's place.

Anti-Patterns (FORBIDDEN)

• Spinner for content loading — Spinners give no spatial hint. Use skeletons matching the content shape.
• Infinite scroll without Load More — Screen readers and keyboard users cannot reach footer content. Always provide a button fallback.
• Modal for browsable content — Modals trap focus and block interaction. Use drawers or inline expansion for browsing.
• Drag-only reorder — Excludes keyboard and assistive tech users. Always provide arrow key + Enter alternatives.
• Toast without ARIA role — Toasts are invisible to screen readers. Use role="status" for success, role="alert" for errors.
• Auto-dismiss error toasts — Users need time to read errors. Never auto-dismiss error notifications.

Detailed Documentation

Related Skills

• ork:ui-components — shadcn/ui component patterns and CVA variants
• ork:animation-motion-design — Motion library and View Transitions API
• ork:accessibility — WCAG compliance, ARIA patterns, screen reader support
• ork:responsive-patterns — Responsive layout and container query patterns
• ork:performance — Core Web Vitals and runtime performance optimization