Solving Pagination Problems for Web Scraping - ESK Solutions
Web design is a dynamic space where advanced coding practices, standards, and design trends change very frequently. Although most of these changes aim to improve the user experience for visitors, bots often find it difficult to navigate a webpage designed with human interests in mind.
Navigating through various pages of a website is an integral part of the scraping process and accounts for much of its automation. However, when you are on the challenging path of scraping, the pagination structure used on websites can often be a tough nut to crack.
Pagination is a crucial element of web design because it helps divide and present content in an easily digestible form for site visitors.
At ESK Solutions, we work with websites of varying complexity, including those with diverse pagination structures. If you are trying to scrape data from a site and are facing the dilemma of how to write a script for different types of pagination, we are here to help you.
Numbered Pagination with Changing URL
Numbered pagination is perhaps one of the oldest and most widely used pagination systems on the Internet. The method of moving through site pages using this type of navigation system is quite simple.
GET requests are used to fetch pages, then a loop is executed to compile a list of pages available on the site. After compiling the page URLs, a queue system is used to automatically fetch HTML data from each page. The actual scraping occurs on the offline pages saved in this manner.
Infinite Scroll Using AJAX
Infinite scroll is commonly used on sites with a large amount of displayed content. Clicking 'next/previous' buttons can be tedious for the user, and infinite scroll solves this problem by automatically loading new content as the user scrolls to the bottom of the page. Infinite scroll is used on many popular websites.
Since infinite page scrolling usually works via AJAX, fetching new pages becomes a challenge. In such cases, it is best to use a browser automation tool like Selenium to simulate human behavior, which in this case is scrolling down.
To extract new pages, Selenium must be programmed to scroll down and count the number of newly loaded elements. If the count increases, the page can be saved. This operation should be repeated until the site stops loading new entries.
AJAX-Based Pagination When the URL Does Not Change
There are websites with a dynamic navigation system where new items are loaded when clicking 'Next/Back' buttons. Unlike numbered pagination, the URL of the webpage does not change in this case because the content is loaded via AJAX calls in the background. Simply put, the webpage behaves like an application and loads data on demand.
Browser automation is the way to go, since writing a program from scratch to simulate AJAX calls that load new content would be difficult. Selenium can be programmed to click the next button 'n' number of times, where n is the number of pages available on the site.
AJAX-Based Pagination When the Number of Pages Is Not Displayed
The approach here is very similar to the AJAX-based pagination when the page URL does not change. However, since the number of pages is unknown, the program must keep clicking the next button until it disappears, which should load all pages available on the site.
Show More/Load More Button
The 'Load More' type navigation is a minor variation of infinite scroll. While the trigger for loading content is page scrolling in the case of infinite scroll, here the user is required to click the 'Load More' button. Selenium is the right approach for this type of navigation since the content is loaded via AJAX calls.
Conclusion
Navigation is a critical component of data scraping services, and to achieve maximum efficiency, the best approach must be used. If navigation is done incorrectly, your scraper may stop, leading to loss of data and time. If you want to avoid the complexities associated with web scraping, you can use our specialized website scraping service.