Introduction to the New React useEffectEvent Hook

React developers, get ready to discover a new tool that will make your life easier. Meet the new useEffectEvent hook, which simplifies how you handle events in your React components. If you’re curious about how it works and want to learn how to use it, keep reading!

What is the useEffectEvent hook?

The useEffectEvent is a custom new React hook that is only available in its experimental version. It allows us to easily add and remove event listeners in your React components.

The useEffectEvent hook takes in three arguments which are:

1. The name of the event to listen for.
2. The callback function to be called when the event is triggered.
3. The element to listen for the event on.

Under the hood, the new useEffectEvent calls useRef and useEffect hooks to save and update the event handler function, while the addEventListener and removeEventListener methods serve as ways to add and remove the event listeners.

Using this hook, you may avoid programming errors and unwanted re-renders when adding or removing event listeners manually from your React components

The Syntax of the useEffectEvent Hook

Using the useEffectEvent hook in your React components will enable you to add event listeners. If you plan on using the useEffectEvent hook in your React application, here are a few important things to keep in mind:

• The useEffectEvent hook requires two arguments which are: The name of the event to listen for (such as click, keydown, etc.) and the function to be called when the event is triggered or executed.
• You can also include an optional third argument. The third argument is for indicating the item on which to listen for the event. If you don’t provide a third argument, the useEffectEvent hook will by default listen for the event on the window object.
• The event listener function should be named and defined outside of the useEffectEvent hook. This helps improves performance and the same function is used for each render cycle.

Benefits of using the useEffectEvent Hook

The new feature brings several benefits for React developers

• It is designed to make working with events in React better and easier. Event listeners can now be registered and unregistered directly in functional components, this was only available in class components.
• The proposed useEffectEvent hook could be a useful addition to the React library because it has the possibility of making working with events in React easier, more straightforward, and more effective.
• The useEffectEvent hook in React has better support for server-side rendering. This means that the hook reduces the risk of errors while trying to register listeners on the server by enabling the smooth registration of event listeners after the componenthas started. The useEffectEvent hook boosts the development of web applications and improves their speed.

Why use the useEffectEvent Hook in your React Application?

The useEffectEvent hook which will be released in the future version of React will be an important tool for managing side effects in functional components in React applications. Developers can quickly complete activities like retrieving data, DOM updating, and API interaction within the scope of a functional component by using this hook. Using the useEffectEvent hook allows a developer to produce code that is simpler to maintain and debug.

The useEffect hook currently in use runs the effect on every render, meanwhile, the newEffectEvent hook only runs the effect if any of the listed dependencies change. This leads to better overall performance. The useEffectEvent hook is a valuable addition to the React toolkit and is certain to become an essential tool for developers creating modern web applications.

At present, the useEffect hook is still being used, but the React team has not declared any plans to remove it entirely at the time when the article was written. However, the team’s indication through the useEffectEvent suggests that this new hook will be utilized more frequently than useEffect in the future.

The following are some benefits of using the useEffectEvent hook in your React application:

• Code made simple: In React, event listeners are normally added in componentDidMount and removed in componentWillUnmount, which can make code lengthy and confusing. The useEffectEvent hook allows for adding and removing event listeners in a single useEffect hook which means utilizing the useEffectEvent hook, you can accomplish both adding and removing event listeners with a single useEffect hook, rather than requiring separate hooks for each. This approach can lead to code that is more succinct and straightforward, potentially minimizing the possibility of issues or glitches that could arise from having numerous hooks managing the same event listener.
• Enhanced results: React components with event listeners may perform badly as a result of memory leaks. However, the useEffectEvent hook provides a more effective method for managing event listeners by ensuring proper addition and removal without any memory leaks.
• Ability to expand: As your React application grows, keeping track of event listeners can become a difficult task. This is particularly true when dealing with complex components that require multiple event listeners for interactivity. One solution to this issue is to use the useEffectEvent hook. Using this hook makes event management easier.

How does the useEffectEvent Hook work?

The React useEffectEvent hook will make it easier for developers to easily add and remove event listeners in their components, as well as provide a simple approach to managing events inside of a component. The useEffectEvent hook works by taking two parameters which are: the event type and a callback function. The hook will listen for a specific event and run a function when the event occurs.

The useEffectEvent hook can be used in combination with other hooks like useState or useContext to develop complex and flexible components. The useEffectEvent hook will be a valuable tool because it offers a simpler way of handling events in a React component function, and it is expected to be widely adopted by developers after being released.

Is the useEffectEvent Hook related to the useEffect?

To understand the difference between these two hooks, it is necessary to first understand what a side effect is in React. A side effect in software development is any action that a particular component or function performs that isn’t meant to render or display something on the screen. For instance, a component might update data in a database, or get data from an external application programming interface (API). Because they have no connection to the main goal of presenting the component on the screen, these actions are classified as side effects.

The useEffect hook was added to React 16.8, allowing developers to manage side effects in functional components. The useEffect hook gives programmers the ability to execute code after a component has finished rendering and offers a method to clean up any resources created during the side effect. This is necessary to stop memory leaks and boost productivity.

While on the other hand, the useEffectEvent hook is a new feature in React that is different from the useEffect hook. The useEffectEvent hook is designed to improve event handling in React by allowing developers to attach event listeners to HTML elements in an easy way.

The useEffectEvent hook may be useful for some developers, but it is not a replacement for the original useEffect hook. It is important to choose the right hook for your specific use case as each one serves different purposes and is designed to solve different problems.

How to use the useEffectEvent Hook with code examples

To build a straightforward timer function in React, we’ll use a piece of code that contains the useEffectEvent directive. This counter function is very simple, and the entire process is explained directly below the code. Simply put, one of the best ways to demonstrate how this works is with the timer component, which is also suggested for use by all developers out there. Please be aware that installing the experimental version of React is required before using the useEffectEvent hook. To do this, install the following lines of code in your project’s work folder.

First, install create a React app:

npx create-react-app myapp

Then, install the following packages for the useEffectEvent:

npm install --save react@experimental react-dom@experimental eslint-plugin-react-hooks@experimental

Once the packages have been installed, React will generate several files, but we only need to use one of them – the App.js file. Please modify the App.js component by copying and pasting the React code provided below:

import { useState, useEffect } from "react";
import { experimental_useEffectEvent as useEffectEvent } from "react";

export default function Timer() {
  const [count, setCount] = useState(0);
  const [increment, setIncrement] = useState(1);
  const [delay, setDelay] = useState(100);

  const onTick = useEffectEvent(() => {
    setCount((c) => c + increment);
  });

  useEffect(() => {
    const intervalId = setInterval(() => {
      onTick();
    }, delay);
    return () => clearInterval(intervalId);
  }, [delay, onTick]);

  const handleReset = () => {
    setCount(0);
  };

  const handleIncrementDecrease = () => {
    if (increment === 0) return;
    setIncrement((i) => i - 1);
  };

  const handleIncrementIncrease = () => {
    setIncrement((i) => i + 1);
  };

  const handleDelayDecrease = () => {
    if (delay === 100) return;
    setDelay((d) => d - 100);
  };

  const handleDelayIncrease = () => {
    setDelay((d) => d + 100);
  };

  return (
    <div className="wrapper">
      <h1 className="header">
        Counter: {count}
        <button onClick={handleReset}>Reset</button>
      </h1>
      <hr />
      <p>
        Increment by:
        <button onClick={handleIncrementDecrease}>-</button>
        <b>{increment}</b>
        <button onClick={handleIncrementIncrease}>+</button>
      </p>
      <p>
        Increment delay:
        <button disabled={delay === 100} onClick={handleDelayDecrease}>
          -100 ms
        </button>
        <b>{delay} ms</b>
        <button onClick={handleDelayIncrease}>+100 ms</button>
      </p>
    </div>
  );
}
CSS:

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

body {
  font-family: sans-serif;
  padding: 0;
  background-color: #ddd;
  margin: 55px;
}
.header {
  background-color: cornflowerblue;
  padding: 10px;
  color: white;
}
h1 {
  margin-top: 0;
  font-size: 22px;
}

h2 {
  margin-top: 0;
  font-size: 20px;
}

h3 {
  margin-top: 0;
  font-size: 18px;
}

h4 {
  margin-top: 0;
  font-size: 16px;
}

h5 {
  margin-top: 0;
  font-size: 14px;
}

h6 {
  margin-top: 0;
  font-size: 12px;
}

code {
  font-size: 1.2em;
}

ul {
  padding-left: 20px;
}

button {
  margin: 10px;
  padding: 10px 30px;
  border-radius: 10px;
}

.wrapper {
  max-width: 60%;
  margin: auto;
  box-shadow: 8px 14px 10px #8d8d8d;
  padding: 10px;
  background-color: white;
}

The React Timer code above displays a simple counter and provides options to adjust the increment and delay between increments. It uses two React hooks, useState and useEffect, to manage state and side effects.

The useState hook is used to create three state variables, count, increment, and delay, which are initialized to 0, 1, and 100, respectively. The count variable represents the current value of the counter, increment represents the amount the counter is incremented by, and delay represents the time between increments in milliseconds.

The useEffectEvent hook is imported from the React library and is used to create an event handler called onTick. The onTickhandler increments the count variable by the current increment value.

The useEffect hook is used to set up a recurring side effect that calls the onTick handler at the specified delay interval. It also cleans up the interval when the component is unmounted.

Lastly, The component renders a div element with class wrapper. The div contains a header with the current value of the counter and a reset button. It also contains two paragraphs with buttons to adjust the increment and delay values. The buttons call corresponding state update functions when clicked (handleReset, handleIncrementDecrease, handleIncrementIncrease, handleDelayDecrease, and handleDelayIncrease).

Output:

When not to use the useEffectEvent Hook

• When it is not necessary to listen for events: UseEffectEvent is not required if your component does not need to listen for any events. It is designed particularly to handle event listeners.
• While using only simple events: If you only need to listen for simple events like the clicks or keyboard press events, then the usual onClick or onKeyDown props may be used in this case.
• If you’re using event listeners outside of React: If you need to use event listeners in codes that are not React, like in standard JavaScript or libraries that are not React, the useEffectEvent might not be the best choice. Because it is a React-specific Hook, it might not function properly in other environments.
• When you need accurate control over event handling: If you require the ability to prevent default actions and more precise handling of events, then using the useEffectEvent might not be the best option for you.
• If you can’t afford the instability of experimental features: useEffectEvent is an experimental feature and it may contain bugs or change behavior in the next version of React.

Best tips and hints for using the useEffectEvent Hook

The following are a few tips and hints for using the useEffectEvent Hook in your React application so that you can get the best results possible:

• Understand the possible risks: React’s experimental features are not yet stable and could change over time. Before using this feature in production code, it is important to recognize the possible risks.
• Always stay up to date: To keep up with any changes to experimental features, always visit the official React documentation and release notes.
• Test carefully: Any code that contains experimental features must be carefully tested to ensure that it performs as intended and does not cause any unexpected issues.
• Implement backup plans: If the experimental feature has not yet been supported by all browsers or platforms, think about using fallbacks or different approaches.

Conclusion

In this article, we looked at using the useEffectEvent hook to handle events in React. By using this hook, developers may write code that is more understandable and reusable while also making it easier to build and manage complex web applications.