| name | optimizely-frontend-component |
| description | Conventions for building accessible, RTL-ready, modular layout/UI components in this Next.js 16 + React 19 + Tailwind 4 + Headless UI 2 codebase. Use this skill whenever the user asks to: (1) build, refactor, or extend any component under src/components/layout/** (Header, Footer, Nav, Sidebar, Drawer); (2) add interactive UI primitives like dropdowns, mega menus, dialogs, popovers, disclosures, command palettes, language switchers, mobile menus; (3) make existing UI keyboard-accessible or RTL-safe; (4) introduce a new family of UI components (cards, banners, ctas) where the modular file layout, data colocation, and a11y/RTL principles below apply. This skill captures the patterns used in src/components/layout/Header/ and src/components/layout/Footer/ — the canonical references. Use when this capability is needed. |
Optimizely Frontend Component Conventions
Principles for building UI components in this codebase. The Header at src/components/blocks/Header/ and Footer at src/components/blocks/Footer/ are the canonical reference implementations — when in doubt, mirror their structure.
When to apply this skill
Apply to anything that renders interactive UI:
- Layout chrome —
Header, Footer, Sidebar, Drawer, breadcrumbs.
- Interactive primitives — dropdowns, mega menus, popovers, disclosures, dialogs, tooltips, tabs, listboxes, comboboxes, language switchers, mobile menus.
- Composable visual blocks where children may be added later (cards, banners, CTAs) and the structure should stay open for extension.
Do not apply this skill to pure CMS content type definitions (use optimizely-cms-content-types) or deployment scripts (use optimizely-frontend-hosting).
Core principles
Each principle has a topical reference under references/ with the full detail.
-
Modular file layout. One concern per file. Subcomponents live next to their parent in a feature folder. Data is colocated. → references/file-layout.md
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Headless UI by default. Any interactive primitive that has a Headless UI equivalent uses it. Don't roll bespoke open/close state machines. The v2 specifics (when to use transition prop, anchor instead of hand-positioning, the click-outside bug) matter. → references/headless-ui.md
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Accessibility is part of "done." Native semantics first, visible focus rings on every interactive element, ARIA wired correctly on toggles, list semantics on lists. → references/accessibility.md
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RTL by default. Use logical CSS properties so <html dir="rtl"> flips the layout for free. Never hand-write dir="rtl" on individual elements. → references/rtl.md
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Open-for-extension data shapes. Schemas should let new entries (children, items, sections) render correctly with zero component edits. The mega menu pattern is the canonical example. → references/mega-menu-pattern.md
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Server-first, client when needed. Mark a file "use client" only when it actually uses hooks, refs, event handlers, or browser APIs. → references/file-layout.md (Server vs client section)
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Keep visual styling out of CMS content types. Visual variants belong in display templates (see optimizely-cms-content-types), not in component prop enums.
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High-level architecture and patterns. This skill captures the high-level architecture and patterns for layout components, including the rationale for the principles above and how they work together to create a scalable, maintainable codebase. → references/layout-architecture.md
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Content resolution. — how content resolution works for layout components, including the use of getContent and getLink helpers, the ContentResolver component, and best practices for structuring content types to work well with these patterns. → references/content-resolution.md
Quick start
For a typical new layout component (a drawer, a sidebar, a mega menu, etc.):
- Read
references/file-layout.md for the folder structure and TypeScript conventions.
- Read
references/headless-ui.md to pick the right primitive and avoid the v2 pitfalls.
- Read
references/accessibility.md and references/rtl.md to know what "done" looks like.
- Look at
references/header-reference.md (CMS driven) and references/footer-reference.md (CMS driven) for annotated walkthroughs of how each principle is applied.
- If something breaks, check
references/troubleshooting.md first — most frontend bugs in this codebase have already been encountered and documented.
Authoring checklist
Before considering any layout/UI component done:
- File layout follows
src/components/layout/<Feature>/ with one concern per file;
- Every interactive primitive uses Headless UI; no hand-rolled open/close state for things HUI covers.
npm run lint is clean; npx tsc --noEmit is clean.- Tab through every interactive surface — focus is always visible, Esc closes overlays, click-outside closes overlays.
- Set
<html dir="rtl"> in DevTools and confirm the layout mirrors with no overlap, no off-canvas, and direction-implying icons (arrows) flip while neutral icons (chevrons-down) stay.
- At the
lg breakpoint boundary, desktop and mobile UIs are mutually exclusive.
- Adding a new entry to the data file renders correctly with zero component edits.
References
references/file-layout.md — Folder structure, data colocation, server-vs-client split, naming, TypeScript conventions.references/headless-ui.md — Primitive lookup table, v2 specifics, annotated examples for Popover and Disclosure.references/accessibility.md — A11y checklist with the rationale and code patterns for each item.references/rtl.md — RTL principles, logical-property mapping, useDocumentLanguage hook, what to flip and what not to.references/mega-menu-pattern.md — Schema and adaptive-layout rules; how to add a new category with zero component edits.references/header-reference.md — Annotated walkthrough of the Header (state-owning shell, Headless UI, RTL toggle, mega menu, mobile drawer); the Header refactor fix log.references/footer-reference.md — Annotated walkthrough of the Footer (server-rendered, content-info landmark, link grid, social icons); the Footer audit fix log; responsive-grid defaults.references/troubleshooting.md — Click-outside doesn't close, Tab stops invisible, span-as-link, RTL doesn't mirror, hydration warnings, file-truncation recovery.references/search-reference — Annotated walkthrough of the Search
Source: abhinavssingh/training-saas-site — distributed by TomeVault.
