Function setValue

packages/react-stately/src/datepicker/useDateFieldState.ts:305–341

(newValue: DateValue | IncompleteDate | null)

  }

  let setValue = (newValue: DateValue | IncompleteDate | null) => {
    if (props.isDisabled || props.isReadOnly) {
      return;
    }

    if (
      newValue == null ||
      (newValue instanceof IncompleteDate && newValue.isCleared(displaySegments))
    ) {
      setDisplayValue(new IncompleteDate(calendar, hourCycle, calendarValue));
      setDate(null);
    } else if (!(newValue instanceof IncompleteDate)) {
      // The display calendar should not have any effect on the emitted value.
      // Emit dates in the same calendar as the original value, if any, otherwise gregorian.
      newValue = toCalendar(newValue, v?.calendar || new GregorianCalendar());
      setDisplayValue(new IncompleteDate(calendar, hourCycle, calendarValue));
      setDate(newValue);
    } else {
      // If the new value is complete and valid, trigger onChange eagerly.
      // If it represents an incomplete or invalid value (e.g. February 30th),
      // wait until the field is blurred to trigger onChange.
      if (newValue.isComplete(displaySegments)) {
        let dateValue = newValue.toValue(calendarValue ?? placeholder);
        if (newValue.validate(dateValue, displaySegments)) {
          let newDateValue = toCalendar(dateValue, v?.calendar || new GregorianCalendar());
          if (!value || newDateValue.compare(value) !== 0) {
            setDisplayValue(new IncompleteDate(calendar, hourCycle, calendarValue)); // reset in case prop isn't updated
            setDate(newDateValue);
            return;
          }
        }
      }

      // Incomplete/invalid value. Set temporary display override.
      setDisplayValue(newValue);
    }
  };

  let dateValue = useMemo(() => {
    let v = displayValue.toValue(calendarValue ?? placeholder);