When building modern web applications with Remix, managing asynchronous data fetching and error handling becomes a challenge yet essential part of the process. Hooks, for example, useAsyncError and useAsyncValue can form a much easier process with improving experience to users. Let us now dive deeper to discuss how these hooks practically operate and are applied through an example that demonstrates its function.
useAsyncError
This hook enables catching any error that may emerge through the asynchronous fetching of data inside a loader or an action. This gives developers a chance to catch and render errors more cleanly, thus improving user experience. Using the useAsyncValue hook, you will be able to capture the loader or action error thrown and return an appropriate message to the user.
useAsyncValue
The useAsyncValue hook fetches data that is supposed to be resolved asynchronously. It most often combines with useAsyncError for the fetching of data which is loaded successfully by either an action or a loader.
Practical Example: Handling Asynchronous Data
Let’s take an example where we fetch data from an API and display it in a component. We will also catch potential errors that might arise with data fetching.
Step 1: Create a Loader
In your Remix route, implement a loader that fetches some data from an external API. For simplicity, let’s use placeholder data:
// app/routes/users.jsx
import { json } from "@remix-run/node";
export async function loader() {
try {
const response = await fetch("https://api.example.com/users");
if (!response.ok) {
throw new Error("Failed to fetch users");
}
return json(await response.json());
} catch (error) {
throw json({ message: error.message }, { status: 500 });
}
}
Step 2: Consume Data and Handle Errors
In the component, use useAsyncValue to access the data and useAsyncError to handle errors.
// app/routes/users.jsx
import { useAsyncError, useAsyncValue } from "@remix-run/react";
function UserList() {
const users = useAsyncValue();
return (
<ul>
{users.map((user) => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
function ErrorBoundary() {
const error = useAsyncError();
return (
<div style={{ color: "red" }}>
<h2>Error</h2>
<p>{error.message}</p>
</div>
);
}
export default function UsersPage() {
return (
<div>
<h1>Users</h1>
<React.Suspense fallback={<p>Loading...</p>}>
<UserList />
</React.Suspense>
</div>
);
}
export { ErrorBoundary };Key Points
- The loader fetches user data and throws an error if the request fails.
- useAsyncValue retrieves the data once it is resolved successfully.
- useAsyncError catches the errors and shows a fallback UI.
Step 3: Add the Route to Remix
Finally, ensure that the route is correctly set up in your Remix project. Add the users.jsx file to the routes folder, and you’re ready to test your application.
Conclusion
The useAsyncError and useAsyncValue hooks represent the powerful tools that asynchronous data and errors in Remix applications. You can thus develop strong, user-friendly applications that will deal with all data-fetching scenarios that result in successful outcomes or those that fail with an adequate grace. From this example, you now have a solid foundation for building projects that use these hooks.
Learn about other Hooks in Remix
