This article delves into a specific aspect of state management - using URL-based state management in a pagination component. We'll analyze a React component that exemplifies this approach.

The Core Concept

The primary function of the discussed pagination component is to read and modify the URL. This method of state management involves synchronizing the component's state with the browser's URL. It allows users to bookmark or share the current state of the application (like a specific page in a pagination system) and maintain that state across sessions.

Check out the demo to see the component in action.

Get the source code on GitHub.

Component Breakdown

The component uses several hooks from next/navigation:

1. useRouter: To manipulate the URL without refreshing the page.
2. usePathname: To obtain the current path.
3. useSearchParams: To access and modify search parameters (query strings) in the URL.

The component initializes the page state based on the URL's query string. If there is a 'page' parameter in the URL, it is used as the initial state; otherwise, it defaults to 1.

The Effect of React.useEffect

The React.useEffect hook in this component is crucial. It listens for changes in the URL's search parameters. Whenever there's a change:

• If no page number is present, it redirects to the base pathname.
• If the page number is '1', it also redirects to the base pathname, effectively removing the redundant 'page=1' from the URL.
• Otherwise, it updates the page state to reflect the current page number from the URL.

The Rendering Logic

The component renders a simple pagination control with 'Previous' and 'Next' buttons. Clicking these buttons triggers a URL update via router.push, appending the new page number as a query string. This action not only updates the component's state but also ensures that the URL reflects the current state.

Advantages of URL-Based State Management

1. Bookmarking and Sharing: Users can bookmark or share URLs to return to or show others a specific state of the application.
2. Consistent User Experience: Reloading or revisiting the URL will restore the same state, leading to a consistent user experience.
3. SEO Friendly: For pages that depend on pagination, having distinct URLs for each page can be beneficial for SEO.

Conclusion

URL-based state management in React, especially in components like pagination, offers an intuitive way to synchronize the application state with the browser's URL. This approach enhances the user experience by making the web application's state shareable and bookmarkable, while also potentially benefiting SEO. The above-discussed component serves as a practical example of implementing this technique effectively.