Function Posts

examples/react/basic/src/index.tsx:36–82

({
  setPostId,
}: {
  setPostId: React.Dispatch<React.SetStateAction<number>>
})

}

function Posts({
  setPostId,
}: {
  setPostId: React.Dispatch<React.SetStateAction<number>>
}) {
  const queryClient = useQueryClient()
  const { status, data, error, isFetching } = usePosts()

  return (
    <div>
      <h1>Posts</h1>
      <div>
        {status === 'pending' ? (
          'Loading...'
        ) : status === 'error' ? (
          <span>Error: {error.message}</span>
        ) : (
          <>
            <div>
              {data.map((post) => (
                <p key={post.id}>
                  <a
                    onClick={() => setPostId(post.id)}
                    href="#"
                    style={
                      // We can access the query data here to show bold links for
                      // ones that are cached
                      queryClient.getQueryData(['post', post.id])
                        ? {
                            fontWeight: 'bold',
                            color: 'green',
                          }
                        : {}
                    }
                  >
                    {post.title}
                  </a>
                </p>
              ))}
            </div>
            <div>{isFetching ? 'Background Updating...' : ' '}</div>
          </>
        )}
      </div>
    </div>
  )
}

const getPostById = async (id: number): Promise<Post> => {
  const response = await fetch(