A Guide to Combining React and Web Components: How to Incorporate External Libraries.

React, since its inception, has changed the face of web development with its component-based architecture. But the broader web ecosystem also gave birth to Web Components, a set of web platform APIs that allow for the creation of reusable, encapsulated widget-like elements. Integrating React with Web Components (especially when dealing with non-React libraries) can be quite powerful, albeit a little tricky. This article explores the ways to bridge the gap between React and Web Components for a seamless developer experience.

What are Web Components?

Web Components are a collection of features that provide a standard component model for the Web. They consist mainly of:

1. Custom Elements: Enables defining and using new HTML elements.
2. Shadow DOM: Encapsulates the styling and the markup of a component.
3. HTML Templates: Defines chunks of markup that go inert but can be activated for use.
4. HTML Imports: (deprecated in favor of ES Modules) Used to include and reuse HTML documents in other HTML documents.

Why Integrate React with Web Components?

There are several reasons:

1. Legacy Code: You might have legacy code that uses Web Components and want to integrate it with a new React application.
2. Shared Components: Web Components can be used with any JavaScript framework or library. If you want a component to be widely available, a Web Component might be the way to go.
3. Library Constraints: Some libraries are available only as Web Components, and integrating them directly can save time and effort.

Integrating Web Components in React

React treats Web Components like DOM elements. Here’s how to integrate them:

1. Passing Properties: For string properties, passing is straightforward. But for non-string, non-dom properties, use a ref and set it in componentDidMount or within a useEffect hook.

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

  useEffect(() => {
    myRef.current.someProperty = someValue;
  }, []);

  return <my-web-component ref={myRef}></my-web-component>;
}

2. Listening to Events: Web Components dispatch custom events. In React, you can add event listeners using camelCased event names.

function MyComponent() {
  function handleCustomEvent(e) {
    console.log(e.detail);
  }

  return <my-web-component onCustomEvent={handleCustomEvent}></my-web-component>;
}

3. Using Forms: If your Web Component contains form elements, remember that React’s form elements are controlled components. You might need to manage the state yourself.

Handling Non-React Libraries

For libraries that aren’t React-based but provide Web Components, the integration process is similar. Here are additional steps:

1. Loading the Library: Ensure you’ve loaded the non-React library before using the Web Components in your React app. This can be done using script tags in the HTML or by using dynamic imports in your JavaScript.
2. Initialization: Some libraries require initialization scripts. Ensure these are run after the component mounts and before it unmounts.

Best Practices

1. Isolation: Isolate the Web Components and the React components as much as possible. This minimizes side effects and makes your components more predictable.
2. Documentation: Due to the hybrid nature of the integration, maintain thorough documentation. It’ll help other developers understand the reasons and methods for integration.
3. Performance: Keep an eye on performance. Integrating Web Components might introduce new re-render scenarios or dependencies.

Conclusion

React and Web Components can coexist in harmony. While both technologies have their strengths and weaknesses, the ability to integrate them provides developers with flexibility and choices. Whether you’re looking to leverage existing Web Components or trying to make your components more widely available, the integration process is worth understanding.