doc.silverstripe.org/src/components/Layout.tsx

import React, { StatelessComponent, useState, ReactNode } from "react";
import Header from './Header';
import Sidebar from './Sidebar';
import useHierarchy from '../hooks/useHierarchy';
import Helmet from 'react-helmet';

interface LayoutProps {
  children?: ReactNode
  pathContext: {
    slug: string;
  }
}
const Layout: StatelessComponent<LayoutProps> = ({ children, pageContext: { slug } }) => {
  const { setCurrentPath, getVersionPath, getCurrentVersion, getCurrentNode, getDefaultVersion, getVersionMessage } = useHierarchy();
  const [isToggled, setSidebarOpen] = useState(false);
  const handleNavigate = () => setSidebarOpen(false);
  
  setCurrentPath(slug);
  const ver = getCurrentVersion();
  const currentNode = getCurrentNode();
  const versionMessage = getVersionMessage();

  return (
    <>
    {currentNode && ver !== getDefaultVersion() && (
      <Helmet
        link={[
          {
            rel: 'canonical',
            href: getVersionPath(currentNode, getDefaultVersion()),
          }
        ]}
       />
    )}
    <Header handleSidebarToggle={() => setSidebarOpen(!isToggled)} />
    <div className={`docs-wrapper container ${isToggled ? 'sidebar-visible' : ''}`}>
    <Sidebar onNavigate={handleNavigate} isOpen={isToggled} />
      <div className="docs-content">
        <div className="container">
          <article role="main" className="docs-article">
            <>
            {versionMessage}
            {children}
            </>
          </article>
        </div> 
      </div>
    </div>
    </>
  );
};
export default Layout;