Function Transitioner

packages/solid-router/src/Transitioner.tsx:12–151

()

import { usePrevious } from './utils'

export function Transitioner() {
  const router = useRouter()
  let mountLoadForRouter = { router, mounted: false }
  const isLoading = useRouterState({
    select: ({ isLoading }) => isLoading,
  })

  if (isServer ?? router.isServer) {
    return null
  }

  const [isSolidTransitioning, startSolidTransition] = Solid.useTransition()

  // Track pending state changes
  const hasPendingMatches = useRouterState({
    select: (s) => s.matches.some((d) => d.status === 'pending'),
  })

  const previousIsLoading = usePrevious(isLoading)

  const isAnyPending = () =>
    isLoading() || isSolidTransitioning() || hasPendingMatches()
  const previousIsAnyPending = usePrevious(isAnyPending)

  const isPagePending = () => isLoading() || hasPendingMatches()
  const previousIsPagePending = usePrevious(isPagePending)

  router.startTransition = (fn: () => void | Promise<void>) => {
    Solid.startTransition(() => {
      startSolidTransition(fn)
    })
  }

  // Subscribe to location changes
  // and try to load the new location
  Solid.onMount(() => {
    const unsub = router.history.subscribe(router.load)

    const nextLocation = router.buildLocation({
      to: router.latestLocation.pathname,
      search: true,
      params: true,
      hash: true,
      state: true,
      _includeValidateSearch: true,
    })

    // Check if the current URL matches the canonical form.
    // Compare publicHref (browser-facing URL) for consistency with
    // the server-side redirect check in router.beforeLoad.
    if (
      trimPathRight(router.latestLocation.publicHref) !==
      trimPathRight(nextLocation.publicHref)
    ) {
      router.commitLocation({ ...nextLocation, replace: true })
    }

    Solid.onCleanup(() => {