Master Selenium: Quick Tricks to Replace Date Pickers and Auto‑Scroll Dynamic Pages

1. Introduction

Selenium is a tool for testing web applications. It runs in the browser like a real user and is essential for crawling complex dynamic pages. It supports browsers such as IE, Firefox, Safari, Chrome, and Opera.

2. Scenario One: Replacing Date Picker Values

Using the 12306 website as an example, the usual method is to locate the date element and click it. After the calendar layout changes, the script may fail. By directly modifying the element’s value attribute with JavaScript, the problem is solved with only three lines of code.

document.getElementById('date_input').value = '2023-01-01';

3. Scenario Two: Automatic Page Scrolling

Some dynamic pages, such as the Tencent Video homepage, require scrolling to reveal all elements. A small JavaScript snippet can scroll the page in ten steps, making every element visible.

for (let i = 1; i <= 10; i++) { window.scrollTo(0, document.body.scrollHeight * i / 10); }

4. Conclusion

Embedding JavaScript in Selenium scripts can solve many crawling challenges. The two examples shown are just a start; consider JavaScript whenever Selenium alone is insufficient. All code is available on GitHub; reply with “selenium” to receive the repository link.