Exploring the New Hooks in React 18: useTransition, useDeferredValue, useId, useSyncExternalStore, and useInsertionEffect

React is a popular JavaScript library for building user interfaces and it is constantly being updated with new features and improvements. In the latest version of React, which is currently React 18, there are several new Hooks that have been introduced, including the useTransition, useDeferredValue, useId, useSyncExternalStore, and useInsertionEffect Hooks.

useTransition

The useTransition Hook allows you to use the Transition component in functional components. It returns an array of objects representing the current set of items, each with an item, props, and key property. You can use the map function to apply the transitions to the items in the array. Here's an example of how to use the useTransition Hook:

import { useTransition } from 'react'

function MyComponent() {
  const [items, setItems] = useState([])
  const transitions = useTransition(items, (item) => item.key, {
    from: { transform: 'translate3d(0,-40px,0)' },
    enter: { transform: 'translate3d(0,0px,0)' },
    leave: { transform: 'translate3d(0,-40px,0)' },
  })
  return (
    <div>
      {transitions.map(({ item, props, key }) => (
        <animated.div key={key} style={props}>
          {item.text}
        </animated.div>
      ))}
    </div>
  )
}

useDeferredValue

The useDeferredValue Hook allows you to use a deferred value for rendering. It is useful for optimizing the performance of components that render expensive values, such as large arrays or complex objects. To use the useDeferredValue Hook, you need to pass it a value and a factory function that returns a new value. The Hook will return the deferred value, which you can use for rendering. Here's an example of how to use the useDeferredValue Hook:

import { useDeferredValue } from 'react'

function MyComponent({ value, factory }) {
  const deferredValue = useDeferredValue(value, factory)
  return <div>{deferredValue}</div>
}

useId

The useId Hook generates a unique ID for a component. It is useful for generating IDs for elements that do not have an ID attribute, such as dynamically created elements. To use the useId Hook, you simply need to call it inside your component and use the returned ID for the element. Here's an example of how to use the useId Hook:

import { useId } from 'react'

function MyComponent() {
  const id = useId()
  return <div id={id}>My component</div>
}

useSyncExternalStore

The useSyncExternalStore Hook allows you to synchronize the state of a component with an external store, such as a Redux store. It is useful for building highly reusable components that can be used with different state management libraries. To use the useSyncExternalStore Hook, you need to pass it a store and a selector function that returns the relevant state for the component. The Hook will return the selected state and an updater function that you can use to update the state in the store. Here's an example of how to use the useSyncExternalStore Hook:

import { useSyncExternalStore } from 'react'

function MyComponent({ store, selector }) {
  const [state, updateState] = useSyncExternalStore(store, selector)
  return (
    <div>
      {state.value}
      <button onClick={() => updateState({ value: 'new value' })}>
        Update state
      </button>
    </div>
  )
}

useInsertionEffect

The useInsertionEffect Hook allows you to perform an effect when a component is inserted into the DOM. It is useful for components that need to perform an action when they are mounted, such as setting up event listeners or making API requests. To use the useInsertionEffect Hook, you need to pass it a function that contains the effect. The Hook will call the function when the component is inserted into the DOM. Here's an example of how to use the useInsertionEffect Hook:

import { useInsertionEffect } from 'react'

function MyComponent() {
  useInsertionEffect(() => {
    console.log('Component was inserted into the DOM')
  })
  return <div>My component</div>
}

These are just a few examples of the many ways you can use the new Hooks introduced in React 18.6. With their powerful and flexible features, these Hooks make it easier to build reusable and performant components in React.

References