Nextjs - keep state and scroll position between page transitions. Described in detail here - https://medium.com/@angus.russell89/next-js-keep-page-components-mounted-between-page-transitions-and-maintain-scroll-position-205b34539a26

_app.js

import React, { useRef, useEffect, memo } from 'react'
import { useRouter } from 'next/router'

const ROUTES_TO_RETAIN = ['/dashboard', '/top', '/recent', 'my-posts']

const App = ({ Component, pageProps }) => {
  const router = useRouter()
  const retainedComponents = useRef({})

  const isRetainableRoute = ROUTES_TO_RETAIN.includes(router.asPath)

  // Add Component to retainedComponents if we haven't got it already
  if (isRetainableRoute && !retainedComponents.current[router.asPath]) {
    const MemoComponent = memo(Component)
    retainedComponents.current[router.asPath] = {
      component: <MemoComponent {...pageProps} />,
      scrollPos: 0
    }
  }

  // Save the scroll position of current page before leaving
  const handleRouteChangeStart = url => {
    if (isRetainableRoute) {
      retainedComponents.current[router.asPath].scrollPos = window.scrollY
    }
  }

  // Save scroll position - requires an up-to-date router.asPath
  useEffect(() => {
    router.events.on('routeChangeStart', handleRouteChangeStart)
    return () => {
      router.events.off('routeChangeStart', handleRouteChangeStart)
    }
  }, [router.asPath])

  // Scroll to the saved position when we load a retained component
  useEffect(() => {
    if (isRetainableRoute) {
      window.scrollTo(0, retainedComponents.current[router.asPath].scrollPos)
    }
  }, [Component, pageProps])

  return (
    <div>
      <div style={{ display: isRetainableRoute ? 'block' : 'none' }}>
        {Object.entries(retainedComponents.current).map(([path, c]) => (
          <div
            key={path}
            style={{ display: router.asPath === path ? 'block' : 'none' }}
          >
            {c.component}
          </div>
        ))}
      </div>
      {!isRetainableRoute && <Component {...pageProps} />}
    </div>
  )
}

export default App

Any thoughts on how to achieve this without window scrolling? For instance, if I’m using a ScrollView from React Native Web (which is just a div with overflow-y: scroll) and I want to restore its scroll position. I suppose I could try to track it globally somehow, but it’s a bit cumbersome to solve.

@nandorojo I'm not familiar with ScrollView but surely it has some way to get and set the scroll position? If so it should be exactly the same but with those methods instead of window.scrollY and window.scrollTo().