ReactJS Hooks are functions that can be reused. When multiple components require the same component logic, it can be extracted into a custom Hook with the prefix “use”. For instance, the useFetch Hook. The primary purpose of creating custom Hooks is to promote code reuse. This way, instead of duplicating the same code in various components that require the same stateful logic (such as a “setState” or localStorage logic), you can encapsulate that logic within a custom Hook and use it across multiple components.
What are Custom Hooks in ReactJS?
Let’s compare custom React JS hooks and React JS components:
- Custom hooks lack a required signature, giving developers the freedom to decide on the arguments and returns.
- The naming convention for custom hooks is to always start with “use”.
- Developers have control over the arguments and return values of a custom hook.
How To Use Custom Hooks
In a given application, multiple components rely on the activity data, which includes a common loading state and activities state. To avoid duplicating code and keep components simple, we can extract this shared state and the shared useEffect fetch hook into a custom hook. This not only isolates testable logic into a separate function but also makes it possible to reuse the shared logic across different components.
It’s important to note that custom hooks have a specific naming convention. The React linting plugin requires custom hooks to be named using the format “use[something]” (for example, useActivitiesData) to assist with bug detection. Adhering to this consistent naming convention makes it easier to identify and fix programming errors, stylistic issues, and potential problem areas.
Since the advent of hooks, developers have developed numerous custom hooks libraries developed to address common front-end needs. For instance, working with local storage (useLocalStorage), memoization (useMemoCompare), and routing (useRoutes). These libraries allow developers to leverage pre-existing solutions, reducing the need to reinvent the wheel in many situations.
Advantages of Using Custom Hooks in ReactJS
Custom hooks provide a level of flexibility in sharing logic that was not previously attainable in React components. You can use them to address a wide range of scenarios such as form handling, animation, declarative subscriptions, timers, and many more. Moreover, custom hooks can be designed to be just as user-friendly as React’s built-in features.
Avoid adding too much abstraction too soon. With the increased capabilities of function components, it’s common for the average function component to become longer. This is normal and there’s no need to rush to split it into hooks. However, another best practice is to identify cases where a custom hook can simplify complex logic or untangle messy components by providing a straightforward interface.
Custom React JS hooks offer a high level of reusability, allowing for cleaner and more efficient code. Once created, developers can easily reuse these hooks, reducing the amount of time spent writing code. Additionally, custom hooks can improve the overall rendering speed by eliminating the need to repeatedly render the hook while rendering the entire code.
Custom hooks can improve code readability compared to using High-Order Components (HOCs). The excessive use of providers, consumers, HOCs, render props, and other abstractions can make complex code difficult to read. This leads to what is commonly referred to as “wrapper hell.” Custom React JS hooks provide a clearer logic. They offer more intuitive way to understand the relationship between data and components, leading to improved readability.
In ReactJS development, it is common to test presentational components and container components separately. This works well for unit tests, but it can become challenging when it comes to integration tests if the container contains multiple HOCs. In such cases, testing both the container and components together is necessary for accurate integration testing.
Custom React JS hooks can simplify this issue by allowing you to merge containers and components into one component. This makes it easier to write separate unit tests for custom hooks and to mock hooks, which is similar to mocking a function. This is easier than mocking HOCs and can lead to a more streamlined testing process.
Custom React JS hooks offer several benefits for developers, including time savings, reliability, and code cleanliness. These hooks are easily reusable, meaning that once you have created one, you can use it across multiple components in your project. This can not only help simplify your code but also make it more maintainable and scalable. Additionally, creating custom React JS hooks is a relatively straightforward process. There are many open-source libraries available that offer a wealth of pre-created hooks that you can use. This can save you time and effort, as you don’t have to reinvent the wheel.