Interacting with Web Page Data

Browser extensions can do more than just change how a web page looks. They can also interact with the data found on a web page!

This lesson explores how your extension can:

• Extract information like text or values from a page.
• Respond to user actions, such as clicks or typing.
• Send this collected information back to your extension's background script for processing.

Let's make your extension smart about web page data!

To interact with data, you first need to locate the specific parts of the web page where that data resides. Your content scripts have access to the page's Document Object Model (DOM), just like regular JavaScript.

You'll use common methods to select elements:

• document.getElementById("myId"): Finds an element by its unique ID.
• document.querySelector(".myClass"): Finds the first element matching a CSS selector.
• document.querySelectorAll("p.info"): Finds all elements matching a CSS selector, returning a NodeList.