function useContextValue()

in packages/docusaurus-theme-common/src/contexts/announcementBar.tsx [46:102]

• 43 lines of code
• 8 McCabe index (conditional complexity)

function useContextValue(): ContextValue {
  const {announcementBar} = useThemeConfig();
  const isBrowser = useIsBrowser();

  const [isClosed, setClosed] = useState(() =>
    isBrowser
      ? // On client navigation: init with local storage value
        isDismissedInStorage()
      : // On server/hydration: always visible to prevent layout shifts (will be hidden with css if needed)
        false,
  );
  // Update state after hydration
  useEffect(() => {
    setClosed(isDismissedInStorage());
  }, []);

  const handleClose = useCallback(() => {
    setDismissedInStorage(true);
    setClosed(true);
  }, []);

  useEffect(() => {
    if (!announcementBar) {
      return;
    }
    const {id} = announcementBar;

    let viewedId = IdStorage.get();

    // retrocompatibility due to spelling mistake of default id
    // see https://github.com/facebook/docusaurus/issues/3338
    // cSpell:ignore annoucement
    if (viewedId === 'annoucement-bar') {
      viewedId = 'announcement-bar';
    }

    const isNewAnnouncement = id !== viewedId;

    IdStorage.set(id);

    if (isNewAnnouncement) {
      setDismissedInStorage(false);
    }

    if (isNewAnnouncement || !isDismissedInStorage()) {
      setClosed(false);
    }
  }, [announcementBar]);

  return useMemo(
    () => ({
      isActive: !!announcementBar && !isClosed,
      close: handleClose,
    }),
    [announcementBar, isClosed, handleClose],
  );
}