How does the HTML Purifier library enhance security measures against XSS attacks in PHP?

XSS attacks occur when user input containing malicious scripts is not properly sanitized before being displayed on a webpage, allowing attackers to execute harmful scripts on unsuspecting users' browsers. To prevent XSS attacks in PHP, developers can use the HTML Purifier library, which thoroughly cleans and filters user input to remove any potentially dangerous HTML or JavaScript code.

// Include the HTML Purifier library
require_once 'path/to/HTMLPurifier.auto.php';

// Create a new instance of HTMLPurifier
$config = HTMLPurifier_Config::createDefault();
$purifier = new HTMLPurifier($config);

// Sanitize user input using HTML Purifier
$clean_html = $purifier->purify($user_input);

// Display the sanitized input on the webpage
echo $clean_html;