Function useBlocker

packages/react-router/src/useBlocker.tsx:151–260

(
  opts?: UseBlockerOpts | LegacyBlockerOpts | LegacyBlockerFn,
  condition?: boolean | any,
)

): BlockerResolver

export function useBlocker(
  opts?: UseBlockerOpts | LegacyBlockerOpts | LegacyBlockerFn,
  condition?: boolean | any,
): BlockerResolver | void {
  const {
    shouldBlockFn,
    enableBeforeUnload = true,
    disabled = false,
    withResolver = false,
  } = _resolveBlockerOpts(opts, condition)

  const router = useRouter()
  const { history } = router

  const [resolver, setResolver] = React.useState<BlockerResolver>({
    status: 'idle',
    current: undefined,
    next: undefined,
    action: undefined,
    proceed: undefined,
    reset: undefined,
  })

  React.useEffect(() => {
    const blockerFnComposed = async (blockerFnArgs: BlockerFnArgs) => {
      function getLocation(
        location: HistoryLocation,
      ): AnyShouldBlockFnLocation {
        const parsedLocation = router.parseLocation(location)
        const matchedRoutes = router.getMatchedRoutes(parsedLocation.pathname)
        if (matchedRoutes.foundRoute === undefined) {
          return {
            routeId: '__notFound__',
            fullPath: parsedLocation.pathname,
            pathname: parsedLocation.pathname,
            params: matchedRoutes.routeParams,
            search: router.options.parseSearch(location.search),
          }
        }

        return {
          routeId: matchedRoutes.foundRoute.id,
          fullPath: matchedRoutes.foundRoute.fullPath,
          pathname: parsedLocation.pathname,
          params: matchedRoutes.routeParams,
          search: router.options.parseSearch(location.search),
        }
      }

      const current = getLocation(blockerFnArgs.currentLocation)
      const next = getLocation(blockerFnArgs.nextLocation)

      if (
        current.routeId === '__notFound__' &&
        next.routeId !== '__notFound__'
      ) {
        return false
      }