10 Recoil JS Best Practices

Recoil is a state management library for React applications that provides an alternative to the popular Redux library. It is designed to make it easier to manage state in complex React applications.

In this article, we will discuss 10 best practices for using Recoil in your React applications. We will cover topics such as how to structure your state, how to use selectors, and how to use atom and selector families. Following these best practices will help you get the most out of Recoil and ensure your React applications are well-structured and performant.

1. Avoid using the useRecoilState hook in render functions

The useRecoilState hook is designed to be used in components that are not rendered on every render cycle. If you use it in a component that is rendered on every render cycle, then the state will be updated unnecessarily and can cause performance issues. Additionally, if the state is updated too often, it can lead to unexpected behavior due to race conditions.

To avoid these issues, make sure to only use the useRecoilState hook in components that are not rendered on every render cycle. This way, you can ensure that your Recoil JS application runs smoothly and efficiently.

2. Use memoization to avoid unnecessary re-renders

Memoization is a technique that stores the results of expensive function calls and returns the cached result when the same inputs occur again. This helps to avoid unnecessary re-renders, as Recoil JS will only update components if the data they depend on has changed. By using memoization, you can ensure that your components are not unnecessarily re-rendered due to unchanged data.

3. Don’t forget about asynchronous updates

When you’re working with Recoil, it’s important to remember that the state updates are asynchronous. This means that if you make a change to your state and then immediately try to access it, you may not get the updated value.

To ensure that you always have the most up-to-date values in your state, you should use the atom family of functions (atom.set(), atom.subscribe(), etc.) to update and read from your state. These functions will guarantee that you always have the latest version of your data when you need it.

4. Only subscribe to atoms that you need

When you subscribe to an atom, Recoil will re-render your component whenever the value of that atom changes. This can lead to unnecessary re-renders and performance issues if you’re subscribing to too many atoms.

To avoid this, make sure to only subscribe to atoms that are necessary for the current view or component. If there’s a piece of data that isn’t needed in the current view, don’t subscribe to it. This will help keep your components performant and efficient.

5. Prefer selectors over derived state

Selectors are functions that take the current state of your application and return a derived value. This means they can be used to access data from multiple atoms, making them more efficient than using derived state.

Derived state is created by combining multiple atoms into one object or array. While this may seem like an easy way to get the data you need, it can quickly become inefficient as your application grows in complexity. Selectors allow you to access the same data without having to create a new object each time.

By preferring selectors over derived state, you can ensure that your Recoil JS applications remain performant and maintainable.

6. Make sure your selector is pure

A pure selector is a function that takes the same input and always returns the same output. This means that if you call your selector with the same parameters, it will always return the same result.

This helps to ensure that your application remains predictable and consistent. If your selector isn’t pure, then different calls may return different results, which can lead to unexpected behavior in your app. Additionally, this makes debugging much easier since you know exactly what data is being returned from each call.

7. Be careful with async selectors

Async selectors are functions that return a promise, and they can be used to fetch data from an external source. However, if you’re not careful with how you use them, they can cause performance issues in your application.

To avoid this, make sure to only call async selectors when necessary. For example, if the same selector is called multiple times within a short period of time, it’s best to cache the result so that the selector isn’t called again until the cached value expires. Additionally, try to limit the number of async selectors you use in your application as much as possible.

8. Define a clear contract for your selectors

Selectors are the functions that you use to access data from your atom or selector. They can be used in multiple places, and if they don’t have a clear contract, it’s easy for them to become inconsistent.

For example, let’s say you have a selector that returns an array of objects. If you’re not careful, you might end up with different types of objects being returned depending on where the selector is called from. To avoid this, make sure to define a clear contract for each selector. This means specifying what type of data should be returned, as well as any other parameters that need to be passed into the selector. Doing so will help ensure consistency across all calls to the selector.

9. Consider using Recoil transactions when updating multiple atoms at once

Recoil transactions are a way to ensure that all of the updates you make to multiple atoms happen atomically, meaning they either all succeed or none of them do. This is important because it prevents race conditions and other issues that can arise when updating multiple atoms at once.

Using Recoil transactions also helps keep your code clean and organized by allowing you to group related updates together in one place. This makes it easier to debug any issues that may arise from making changes to multiple atoms at once.

10. Keep your atom values as small as possible

When you create an atom, it will be stored in the global state tree. This means that any component that uses this atom will have access to its value and can update it at any time.

If your atom values are too large or complex, they can become difficult to manage and debug. It’s best to keep them as small and simple as possible so that components can easily read and write their values without causing unexpected side effects. Additionally, keeping atom values small makes it easier to test and refactor code since there is less data to work with.