What are some potential pitfalls of using visitor-dependent layouts in PHP?

One potential pitfall of using visitor-dependent layouts in PHP is that it can lead to code duplication and maintenance issues if the logic for determining the layout is scattered throughout the codebase. To solve this, you can centralize the layout determination logic in a separate function or class to make it easier to manage and update.

function getLayoutForVisitor() {
    // logic to determine layout based on visitor
    if ($_SESSION['user_type'] == 'admin') {
        return 'admin_layout.php';
    } else {
        return 'default_layout.php';
    }
}

// In your PHP file
include getLayoutForVisitor();