Unlock the Power of useSWR: Advanced Use Cases and Best Practices
When it comes to handling client-side data fetching and handling, developers often face a dilemma. You either have to set up a state management system or settle for the useEffect Hook. But with SWR (Stale-While-Revalidate), fetching and handling client-side data has never been easier.
Basics of the useSWR Hook
The useSWR Hook accepts three parameters: key, fetcher, and options. The key param represents the URL to which the request is made, while the fetcher param is a function that returns a promise of the fetched data. The options param allows you to tweak the way the data is handled.
Advanced useSWR Use Cases
Pagination with useSWR
SWR comes with built-in support for easily handling pagination. You can use the pageIndex state to change the cached key when it is changed, causing SWR to request new data from the API.
Caching with SWR
By default, SWR uses a global cache to store and share data across all your components. You can also create a custom cache provider like window’s localStorage property or IndexedDB to store larger amounts of data and persist it across page reloads.
Conditional Fetching with useSWR
The key param can also be a function, as long as it returns a string, array, object, or a falsy value. When fetching data that depends on another, you can either pass a function to the key param or use a ternary operator directly.
Using useSWR for Subscriptions
One other useful feature of useSWR is the useSWRSubscription Hook, which is used for subscribing to real-time data.
Best Practices and Optimization Techniques
Reusable Data Fetching with SWR
When fetching similar data across your application, it is best to make fetching the data reusable to avoid duplicate code and optimize code efficiency and maintainability.
Type Safety with useSWR
SWR supports TypeScript out of the box, allowing you to specify the types of arguments for the fetcher function.
Mutation and Revalidation
Mutation is simply for updating the data of a cached key while revalidating whenever/however triggered re-fetches a cached key.
Error Handling Strategies with useSWR
As a developer, when an error is thrown when fetching data, you can either decide to display the error or try fetching again.
Testing Strategies
Testing useSWR can seem daunting at first, but it’s an essential step to ensure your React applications work smoothly. Some testing strategies include testing data fetching by crafting mock API responses, testing caching behavior, and testing loading states.
SSG/ISR/SSR Support
Having a statically generated blog improves search engine performance and load times. Despite pre-rendering, client-side data fetching is still essential for real-time views, comments, authentication, and data revalidation.
Client-side Data Fetching vs. Server-side Data Fetching
Client-side data fetching fetches your data after the page has been rendered, while server-side data fetching fetches your data before the page is rendered. The key is to determine which method aligns best with your specific goals for a web page.
By mastering useSWR, you can unlock the full potential of client-side data fetching and handling, and take your React applications to the next level.