Managing state and fetching data in React applications can often become complex. Developers frequently struggle with granular state management, manual refetching, and the notorious "async-spaghetti" that comes with handling asynchronous operations. These challenges can lead to code that is difficult to maintain and scale.

As the TansStack query documentation mentions, "Toss out that granular state management, manual refetching, and endless bowls of async-spaghetti code." TanStack Query revolutionizes this process by offering a declarative approach to managing queries and mutations, making your codebase cleaner and more efficient.

TanStack Query also recognized as React Query, temporarily stores the responses from API requests so that the TanStack Query can be quickly retrieved later without making another network call. And just like that, you've seen how caching works! This helps improve performance by reducing the need to repeatedly fetch the same data from the server. In a nutshell, it makes caching API requests so simple.

Let's compare traditional data management with TanStack Query to see how it simplifies state handling, refetching, and async code.

1. Granular State Management

With traditional state management, you'd often handle individual pieces of data manually, which can get complex as your app grows. TanStack Query abstracts this by managing the state of your data.

Note: All the code snippets in this article uses React Query version 5.

But with TanStack query:

Just like that, all the boilerplate code is gone, saving you tons of lines of code and simplifying the process.

2. Manual Refetching

Keeping your data updated by manually refetching it can be a real hassle. However, TanStack Query offers a more streamlined approach, allowing data to be automatically refetched when specific conditions are met.

Without Tanstack Query:

With Tanstack Query:

Deciding when and how often to refetch data depends on your use case. Since there isn't a universal solution that fits all scenarios, React Query offers the flexibility to control both the timing and the conditions for triggering refetching.

3. Async-Spaghetti Code:

Async operations can lead to nested promises or callbacks, making the code hard to maintain. TanStack Query handles this complexity, providing a clean and straightforward API.

Without Tanstack Query:

Problems with this approach:

Code Duplication: You must duplicate each query's loading, error handling, and data fetching logic.

Manual Fetching Logic: Managing useEffect calls for dependent data (like fetching user data after the initial data) requires more code and makes the flow harder to follow.

No Caching or Refetching: React Query handles caching, background refetching, retries, and more. Without React Query, you would need to implement these features yourself.

**Increased Complexity: **As your app grows and more data is needed, the complexity increases. You'll need to add more useState and useEffect hooks for each new piece of data you need to fetch.

Let's see how React query solves this

React Query eliminates the need to manually manage async operations, error handling, and loading states.

Does React Query (TanStack Query) Eliminate the Need for useEffect hook?

You may have noticed that the useEffect hooks were removed from the above code. Does that mean we can eliminate the need for useEffect with React Query (TanStack Query)?

Yes and no. React Query can often replace the need for useEffect regarding data fetching. This is because React Query abstracts away much of the boilerplate code typically written in useEffect for managing the loading state, making API calls, and handling errors. It provides a declarative way to fetch and manage data, allowing you to focus on the data rather than the fetching logic.

However, React Query does not entirely eliminate the need for useEffect. useEffect is still essential for side effects unrelated to data fetching, such as:

• DOM manipulations
• Setting up subscriptions
• Timers and intervals
• Manual cleanups

This powerful library simplifies code, improves readability, and reduces the "async spaghetti" problem.

With React Query, you can easily chain multiple dependent API calls cleanly and declaratively without the mess of manual state management.

This refactor using React Query makes the code much more maintainable, scalable, and less prone to bugs caused by complex async logic.

Conclusion

TanStack Query simplifies data fetching, eliminating boilerplate and reducing async complexity. While it replaces useEffect for fetching, it doesn’t remove the need for side effects. With built-in caching, background updates, and automatic retries, it seamlessly handles server state. Whether using REST or GraphQL, React Query enhances performance, readability, and developer efficiency—a must-have for modern React apps.