Function Example

examples/react/load-more-infinite-scroll/src/pages/index.tsx:21–121

()

}

function Example() {
  const { ref, inView } = useInView()

  const {
    status,
    data,
    error,
    isFetching,
    isFetchingNextPage,
    isFetchingPreviousPage,
    fetchNextPage,
    fetchPreviousPage,
    hasNextPage,
    hasPreviousPage,
  } = useInfiniteQuery({
    queryKey: ['projects'],
    queryFn: async ({
      pageParam,
    }): Promise<{
      data: Array<{ name: string; id: number }>
      previousId: number
      nextId: number
    }> => {
      const response = await fetch(`/api/projects?cursor=${pageParam}`)
      return await response.json()
    },
    initialPageParam: 0,
    getPreviousPageParam: (firstPage) => firstPage.previousId,
    getNextPageParam: (lastPage) => lastPage.nextId,
  })

  React.useEffect(() => {
    if (inView && hasNextPage && !isFetchingNextPage) {
      fetchNextPage()
    }
  }, [inView, hasNextPage, isFetchingNextPage, fetchNextPage])

  return (
    <div>
      <h1>Infinite Loading</h1>
      {status === 'pending' ? (
        <p>Loading...</p>
      ) : status === 'error' ? (
        <span>Error: {error.message}</span>
      ) : (
        <>
          <div>
            <button
              onClick={() => fetchPreviousPage()}
              disabled={!hasPreviousPage || isFetchingPreviousPage}
            >
              {isFetchingPreviousPage
                ? 'Loading more...'
                : hasPreviousPage
                  ? 'Load Older'
                  : 'Nothing more to load'}
            </button>
          </div>