Loading External Scripts in React

Loading external scripts in React can be a bit tricky due to the way React handles DOM updates. In this tutorial, we’ll explore the reasons behind this behavior and learn how to load external scripts in a React application.

Why Loading External Scripts is Different in React

When you try to render a script tag in JSX, it doesn’t work as expected. This is because React uses the innerHTML DOM API to update the DOM, which does not execute script tags added as a security consideration. To load external scripts in React, we need to use alternative approaches.

Using componentDidMount or useEffect

One way to load an external script is by creating a new script element and appending it to the document body using componentDidMount or useEffect. Here’s an example:

import React, { useEffect } from 'react';

const MyComponent = () => {
  useEffect(() => {
    const script = document.createElement('script');
    script.src = 'https://use.typekit.net/foobar.js';
    script.async = true;
    document.body.appendChild(script);
    return () => {
      document.body.removeChild(script);
    };
  }, []);

  return <div>Hello World!</div>;
};

This approach loads the script only once when the component is mounted.

Using a Custom Hook

We can also create a custom hook to load external scripts. Here’s an example:

import { useEffect } from 'react';

const useScript = (url) => {
  useEffect(() => {
    const script = document.createElement('script');
    script.src = url;
    script.async = true;
    document.body.appendChild(script);
    return () => {
      document.body.removeChild(script);
    };
  }, [url]);
};

export default useScript;

We can then use this hook in our components:

import React from 'react';
import useScript from './useScript';

const MyComponent = () => {
  useScript('https://use.typekit.net/foobar.js');
  return <div>Hello World!</div>;
};

Using React Helmet

Another approach is to use React Helmet, a library that allows you to manage the document head in your React application. Here’s an example:

import React from 'react';
import { Helmet } from 'react-helmet';

const MyComponent = () => {
  return (
    <div>
      <Helmet>
        <script src="https://use.typekit.net/foobar.js" />
      </Helmet>
      Hello World!
    </div>
  );
};

Conclusion

Loading external scripts in React requires a different approach than simply rendering a script tag. By using componentDidMount, useEffect, custom hooks, or libraries like React Helmet, we can load external scripts safely and efficiently.

Best Practices

When loading external scripts in React, keep the following best practices in mind:

• Use componentDidMount or useEffect to load scripts only when necessary.
• Create a custom hook to load scripts if you need to reuse the logic.
• Use libraries like React Helmet to manage the document head.
• Always remove the script element when it’s no longer needed to avoid memory leaks.

By following these best practices and using the approaches outlined in this tutorial, you can load external scripts in your React application with confidence.