[EuiDelayHide] Migrate from class to function component #9500
Description
EuiDelayHide delays hiding its children for a specified duration after the hide prop becomes true. Used for loading indicator UX.
- File:
components/delay_hide/delay_hide.tsx - Class size: 76 lines
- State:
hide,countdownExpired - Lifecycle:
getDerivedStateFromProps,componentDidMount,componentDidUpdate,componentWillUnmount
Migration notes:
Small but has the full lifecycle suite including getDerivedStateFromProps. Timer management maps to useEffect cleanup. The derived state pattern needs careful conversion.
Acceptance criteria:
- Convert to function component with hooks
- Maintain delay timing behavior
- All existing tests pass