react-query/examples/react/star-wars/src/Film.jsx

import React from 'react'
import { Typography, Link } from '@mui/material'
import { useParams, Link as RouterLink } from 'react-router-dom'
import { useQuery } from '@tanstack/react-query'
import fetch from './fetch'

function Film() {
  let params = useParams()
  const filmId = params.filmId
  const { data, status, error } = useQuery({
    queryKey: ['film', filmId],
    queryFn: () => fetch(`https://swapi.dev/api/films/${filmId}/`),
  })

  if (status === 'pending') return <p>Loading...</p>
  // this will not be necessary when v1 is released.
  if (data == null) {
    console.info("this shouldn't happen but it does 2")
    return <p>Loading...</p>
  }
  if (status === 'error') return <p>Error :(</p>
  return (
    <div>
      <Typography variant="h2">{data.title}</Typography>
      <Typography variant="body1">{data.opening_crawl}</Typography>
      <br />
      <Typography variant="h4">Characters</Typography>
      {data.characters.map((character) => {
        const characterUrlParts = character.split('/').filter(Boolean)
        const characterId = characterUrlParts[characterUrlParts.length - 1]
        return <Character id={characterId} key={characterId} />
      })}
    </div>
  )
}

function Character(props) {
  const { id } = props
  const { data, status, error } = useQuery({
    queryKey: ['character', id],
    queryFn: () => fetch(`https://swapi.dev/api/people/${props.id}/`),
  })

  if (status !== 'success') {
    return null
  }

  return (
    <article key={id}>
      <Link component={RouterLink} to={`/characters/${id}`}>
        <Typography variant="h6">{data.name}</Typography>
      </Link>
    </article>
  )
}

export default Film