How to Access and Manipulate DOM Elements in React

While working on a React application, it is not usually necessary to handle DOM since React handle it through its Virtual DOM mechanism which provides a more efficient way to manipulate the DOM.

However, there are still situations where you may need to access a DOM element directly, such as when working with third-party libraries or implementing certain browser APIs.

So, in this article, we will explore different ways to access a DOM element in React.

Using Refs

Refs in React are a way to access the DOM node of a component. You can create a ref using the useRef hook or by using the createRef method. Once you have a ref, you can pass it as a prop to a component and then use it to find the DOM element.

Here is an example of how to create a ref and find a DOM element:

import { useRef } from 'react';

function MyComponent() {
  const myRef = useRef(null);

  function handleClick() {
    myRef.current.focus();
  }

  return (
    <div>
      <input type="text" ref={myRef} />
      <button onClick={handleClick}>Focus Input</button>
    </div>
  );
}

In this example, we create a ref using the useRef hook and pass it to the input element using the ref prop. We then create a handleClick function that uses the current property of the ref to access the input element and call its focus method.

Using the DOM API

Another way to access a DOM element in React is by using the DOM API directly. You can do this by using the document.querySelector method or any other method available in the browser’s DOM API such as getElementById, etc.

Here is an example of how to access a DOM element using the document.querySelector method:

function MyComponent() {
  function handleClick() {
    const input = document.querySelector('input[type="text"]');
    input.focus();
  }

  return (
    <div>
      <input type="text" />
      <button onClick={handleClick}>Focus Input</button>
    </div>
  );
}

In this example, we use the document.querySelector method to select the input element and then call its focus method.

It is important to note that accessing the DOM directly can have negative performance implications, especially if you are doing it frequently or in a large-scale application. If possible, it is recommended to use refs instead.

Dom In React: Traditional Vs Virtual

We’ve talked about the Virtual Dom in the beginning. It’s useful to understand the differences between the traditional and Virtual DOM in order to understand their impact on performance in a React application.

Traditional DOM

The Document Object Model (DOM) is a programming interface for HTML and XML documents. It represents the structure of a document as a tree-like structure where each node represents an element, attribute or piece of text in the document.

Virtual DOM

On the other hand, The Virtual DOM is a lightweight representation of the actual DOM used by React. It is an in-memory data structure that mirrors the structure of the actual DOM. When changes are made to the Virtual DOM, React compares the previous Virtual DOM with the new one to determine what changes need to be made to the actual DOM.

Why is the Virtual DOM important?

The Virtual DOM is important for several reasons:

• Performance

Manipulating the actual DOM can be a slow and expensive operation, especially for large-scale applications with many elements. The Virtual DOM allows React to batch updates and minimize the number of actual DOM updates required. This can significantly improve the performance of the application.

• Cross-platform compatibility

The Virtual DOM is a platform-independent abstraction layer that allows React to work seamlessly across different platforms and browsers. This makes it easier to write code that works consistently across different environments.

• Developer experience

The Virtual DOM allows you to write code that is more declarative and less imperative. Instead of manually updating the DOM, you can describe how the UI should look and React takes care of the rest. This can make it easier to reason about the code and reduce the likelihood of bugs.

Best Practises For Manipulating DOM

As the React app grows, a bad practice can have a bad effect on the app, so you should consider applying the following best practices in your React app.

Use State to Control DOM Elements

As react use Virtual DOM, you need to conditionally show or hide a DOM element based on some state in your application. For example, you might want to show a loading spinner while data is being fetched from an API.

In these cases, you should use state to control the visibility of the DOM element. You can use the useState hook to create a boolean state variable, and then use that variable to conditionally render the DOM element.

import React, { useState } from 'react';

function MyComponent() {
  const [isLoading, setIsLoading] = useState(false);

  function fetchData() {
    setIsLoading(true);

    // Make API request
    fetch('/api/data')
      .then(response => response.json())
      .then(data => {
        // Process data
        setIsLoading(false);
      });
  }

  return (
    <div>
      {isLoading && <div>Loading...</div>}
      <button onClick={fetchData}>Fetch Data</button>
    </div>
  );
}

Using state to control DOM elements is a safer and more efficient way to manipulate the DOM in React, as it allows React to handle the rendering logic and ensures that the DOM stays in sync with the application state.

Use React Animation Libraries

Animating DOM elements can be a challenging task, especially when working with complex animations or animations that require precise timing. Fortunately, there are several React animation libraries available that can help simplify this task and provide a consistent and reliable animation experience across different browsers and devices.

Some popular React animation libraries include:

• React Spring: A spring-physics based animation library that provides a simple and flexible API for creating animations.
• React Transition Group: A library that provides a way to transition elements in and out of the DOM using CSS transitions and animations.
• Framer Motion: A motion library that provides a simple and intuitive API for creating complex animations and interactions.

Using a React animation library can help simplify the process of animating DOM elements in React and provide a more consistent and reliable animation experience.

Conclusion

In this article, we explored two ways to access a DOM element in React: using refs and using the DOM API directly. While refs are generally preferred because they are more efficient and provide a more React-like approach, there may be situations where accessing the DOM directly is necessary.

Thank you for reading.