Debugging Path Params Issues in TanStack Router

Offer strategies for debugging common problems encountered with path params in TanStack Router, such as mismatches or undefined values, including tips for logging and tracing parameter usage.

import { useParams } from 'tanstack/react-router';

function UserProfile() {
  const params = useParams();
  // Log the params to see what is being received
  console.log('Route params:', params);

  // Check if the userId param is undefined
  if (!params.userId) {
    console.error('UserId path param is undefined.');
    return <div>Missing user ID.</div>;
  }

  return (
    <div>User profile page for user ID: {params.userId}</div>
  );
}

This code imports the useParams hook from TanStack Router and uses it inside a UserProfile component to access route parameters. It logs the entire params object for debugging purposes and checks if the userId parameter is undefined, logging an error and rendering an error message if so. This is a practical approach for debugging and understanding issues related to path parameters being undefined or incorrect.

import { createBrowserRouter, Route } from 'tanstack/react-router';

const router = createBrowserRouter([
  {
    path: 'user/:userId',
    element: <UserProfile />,
    loader: async ({ params }) => {
      // Log the params in the loader for tracing
      console.log('Loading data for user:', params.userId);
      // Placeholder for actual data fetching logic
    }
  }
]);

This snippet demonstrates the use of TanStack Router's createBrowserRouter and Route to define a dynamic route with a path parameter (userId). It includes a loader function where the userId parameter is logged, assisting in tracing how and when data loading occurs based on path parameters. This is valuable for debugging issues related to data fetching and dynamic routing.