Function useSetLoading

src/loading/context.js:14–100

()

const LoadingContext = createContext({})

export const useSetLoading = () => {
  const loadingId = useRef(uuidv4())
  const loading = useRef(false)
  const { dispatch } = useContext(LoadingContext)
  const [metadataIds, setMetadataIds] = useState(new Set())
  const [chunkIds, setChunkIds] = useState(new Set())

  useEffect(() => {
    return () => {
      const loaders = [{ id: loadingId.current, key: 'loading' }]
      metadataIds.forEach((id) => loaders.push({ id, key: 'metadata' }))
      chunkIds.forEach((id) => loaders.push({ id, key: 'chunk' }))
      dispatch({ loaders, type: 'clear' })
    }
  }, [])

  useEffect(() => {
    if (loading.current && metadataIds.size === 0 && chunkIds.size === 0) {
      dispatch({
        loaders: [{ id: loadingId.current, key: 'loading' }],
        type: 'clear',
      })
      loading.current = false
    }
  }, [metadataIds.size, chunkIds.size, loading.current])

  const setLoading = useCallback((key = 'chunk') => {
    if (!['chunk', 'metadata'].includes(key)) {
      throw new Error(
        `Unexpected loading key: ${key}. Expected one of: 'chunk', 'metadata'.`
      )
    }

    const id = uuidv4()
    const setter = key === 'metadata' ? setMetadataIds : setChunkIds
    setter((prev) => {
      prev.add(id)
      return prev
    })

    const loaders = [{ id, key }]

    if (!loading.current) {
      loaders.push({ id: loadingId.current, key: 'loading' })
      loading.current = true
    }
    dispatch({ loaders, type: 'set' })
    return id
  }, [])

  const clearLoading = useCallback((id, { forceClear } = {}) => {
    if (id) {
      setMetadataIds((prevMetadata) => {
        prevMetadata.delete(id)
        return prevMetadata
      })
      setChunkIds((prevChunk) => {
        prevChunk.delete(id)