afv-library/skills/building-webapp-react-components/implementation/header-footer.md

Implementation — Header / Footer

Rules

1. Edit appLayout.tsx only — header and footer are layout-level concerns. Never add them to individual page files.
2. Never modify routes.tsx or app.tsx — the router setup must remain intact.
3. Create component files in src/components/layout/ — the designated location for layout-level components.
4. Use the full-height flex column pattern — wrap layout in min-h-screen flex flex-col so footer stays at bottom.
5. Use shadcn and Tailwind — compose from @/components/ui; style with Tailwind utility classes and design tokens.
6. Use path aliases — import with @/components/layout/... and @/components/ui; no deep relative paths.
7. Preserve existing content — if appLayout.tsx already has a <NavigationMenu /> or other shell elements, keep them in place.

Step 1 — Create the header component (if requested)

Create src/components/layout/AppHeader.tsx:

import { cn } from "@/lib/utils";

interface AppHeaderProps {
  className?: string;
}

export function AppHeader({ className }: AppHeaderProps) {
  return (
    <header
      className={cn(
        "w-full border-b bg-background px-4 sm:px-6 lg:px-8 py-4",
        className,
      )}
    >
      <div className="max-w-7xl mx-auto flex items-center justify-between">
        <span className="text-lg font-semibold text-foreground">My App</span>
      </div>
    </header>
  );
}

Step 2 — Create the footer component (if requested)

Create src/components/layout/AppFooter.tsx:

import { cn } from "@/lib/utils";

interface AppFooterProps {
  className?: string;
}

export function AppFooter({ className }: AppFooterProps) {
  return (
    <footer
      className={cn(
        "w-full border-t bg-background px-4 sm:px-6 lg:px-8 py-4",
        className,
      )}
    >
      <div className="max-w-7xl mx-auto text-center text-sm text-muted-foreground">
        &copy; {new Date().getFullYear()} My App. All rights reserved.
      </div>
    </footer>
  );
}

Step 3 — Edit appLayout.tsx

Open src/appLayout.tsx — this is the only file to modify for layout-level additions. Wrap existing content in a flex column and add header above and footer below <Outlet />:

import { Outlet } from "react-router";
import { AppHeader } from "@/components/layout/AppHeader";
import { AppFooter } from "@/components/layout/AppFooter";
// Keep all existing imports unchanged

export default function AppLayout() {
  return (
    <div className="min-h-screen flex flex-col bg-background">
      <AppHeader />
      {/* Keep any existing NavigationMenu or other shell elements here */}
      <main className="flex-1">
        <Outlet />
      </main>
      <AppFooter />
    </div>
  );
}

File Locations — Header / Footer

Component	File	Export
Header	src/components/layout/AppHeader.tsx	Named export
Footer	src/components/layout/AppFooter.tsx	Named export
Layout shell	src/appLayout.tsx	Default export (edit in place)

Why appLayout.tsx — Not Pages or Routes

AppLayout is the single shell rendered at the root route. Every page is a child rendered via <Outlet />. Placing the header and footer here ensures they appear on every page without touching individual pages or the route registry.

AppLayout (appLayout.tsx)
├── AppHeader          ← renders on every page
├── NavigationMenu     ← keep if already present
├── <Outlet />         ← active page renders here
└── AppFooter          ← renders on every page

Useful Patterns — Header / Footer

• Sticky header: add sticky top-0 z-50 to the <header> element
• Separator: use <Separator /> from @/components/ui instead of border-b/border-t if a visible divider is preferred
• Nav links in header: use <Button variant="ghost" asChild> wrapping a React Router <Link>
• Icons: lucide-react; add aria-hidden="true" on decorative icons
• Design tokens: bg-background, text-foreground, text-muted-foreground, border, bg-primary

Mobile hamburger / Menu icon — Must be functional

If the header includes a hamburger or Menu icon for mobile:

• Do not add a Menu/hamburger icon that does nothing. It must toggle a visible mobile menu.
• Required: (1) State: const [isOpen, setIsOpen] = useState(false). (2) Button: onClick={() => setIsOpen(!isOpen)}, aria-label="Toggle menu". (3) Conditional panel: {isOpen && ( <div>...nav links...</div> )} with responsive visibility (e.g. md:hidden). (4) Close on navigate: each link in the panel should onClick={() => setIsOpen(false)}.
• Implement in appLayout.tsx (or the component that owns the header). Use the Menu icon from lucide-react.

Confirm — Header / Footer

• Header and footer appear on every page (navigate to at least two routes)
• Imports use path aliases (@/components/layout/...)
• No inline style={{}} — Tailwind only
• src/routes.tsx and src/app.tsx are unchanged