Function useCalendarBase

packages/react-aria/src/calendar/useCalendarBase.ts:45–140

(
  props: CalendarPropsBase & DOMProps & AriaLabelingProps,
  state: CalendarState<CalendarSelectionMode> | RangeCalendarState
)

}

export function useCalendarBase(
  props: CalendarPropsBase & DOMProps & AriaLabelingProps,
  state: CalendarState<CalendarSelectionMode> | RangeCalendarState
): CalendarAria {
  let stringFormatter = useLocalizedStringFormatter(intlMessages, '@react-aria/calendar');
  let domProps = filterDOMProps(props);

  let title = useVisibleRangeDescription(
    state.visibleRange.start,
    state.visibleRange.end,
    state.timeZone,
    false
  );
  let visibleRangeDescription = useVisibleRangeDescription(
    state.visibleRange.start,
    state.visibleRange.end,
    state.timeZone,
    true
  );

  // Announce when the visible date range changes
  useUpdateEffect(() => {
    // only when pressing the Previous or Next button
    if (!state.isFocused) {
      announce(visibleRangeDescription);
    }
  }, [visibleRangeDescription]);

  // Announce when the selected value changes
  let selectedDateDescription = useSelectedDateDescription(state);
  useUpdateEffect(() => {
    if (selectedDateDescription) {
      announce(selectedDateDescription, 'polite', 4000);
    }
    // handle an update to the caption that describes the currently selected range, to announce the new value
  }, [selectedDateDescription]);

  let errorMessageId = useSlotId([
    Boolean(props.errorMessage),
    props.isInvalid,
    props.validationState
  ]);

  // Pass the label to the child grid elements.
  hookData.set(state, {
    ariaLabel: props['aria-label'],
    ariaLabelledBy: props['aria-labelledby'],
    errorMessageId,
    selectedDateDescription
  });

  // If the next or previous buttons become disabled while they are focused, move focus to the calendar body.
  let [nextFocused, setNextFocused] = useState(false);
  let nextDisabled = props.isDisabled || state.isNextVisibleRangeInvalid();
  if (nextDisabled && nextFocused) {
    setNextFocused(false);
    state.setFocused(true);
  }