kvm/useLocation_refactoring_summary.md

useLocation() Refactoring Summary

Goal

Remove the useLocation() hook from /ui/src/routes/devices.$id.tsx to prevent unnecessary re-renders when nested routes are rendered.

Problem

The useLocation() hook was being used in two places in the main device component:

1. In the onModalClose callback - checking if the current path is not "/other-session"
2. In the ConnectionStatusElement useMemo - checking if the current path includes "other-session"

When nested routes rendered, this caused the entire component to re-render due to location changes.

Solution Implemented

1. Removed useLocation() Import and Usage

• Removed useLocation from the React Router imports
• Removed const location = useLocation(); from the component

2. Replaced ConnectionStatusElement Logic

Before:

• Used a useMemo that depended on location.pathname
• This caused re-renders whenever the location changed

After:

• Created a createConnectionStatusElement helper function that accepts pathname as a parameter
• Use window.location.pathname to get the current path without subscribing to React Router's location changes
• This eliminates the dependency on the React Router location state

3. Replaced onModalClose Logic

Before:

const onModalClose = useCallback(() => {
  if (location.pathname !== "/other-session") navigateTo("/");
}, [navigateTo, location.pathname]);

After:

const onModalClose = useCallback(() => {
  // Get the current pathname without useLocation
  const currentPathname = window.location.pathname;
  if (currentPathname !== "/other-session") navigateTo("/");
}, [navigateTo]);

Benefits

1. Prevents Unnecessary Re-renders: The component no longer re-renders when nested routes change location
2. Maintains Same Functionality: All existing behavior is preserved
3. Performance Improvement: By removing the React Router location dependency, the component only re-renders when its own state or props change
4. Clean Implementation: Uses native window.location.pathname instead of React Router's location state for simple pathname checks

Verification

• TypeScript compilation passes without errors
• Build completes successfully
• All functionality is preserved while eliminating the re-render issue

Files Modified

• /ui/src/routes/devices.$id.tsx - Main component refactored to remove useLocation dependency

The refactoring successfully achieves the goal of preventing unnecessary re-renders while maintaining all existing functionality.