How to substitute a class in Thymeleaf?

Question

Spring

Application on Spring Boot. Thymeleaf template engine
There is a url in the controller, by which the html page appears.
There is a menu with links on the page. The menu is the same on each page, except that the color of the active link changes. In order not to create a menu on the page every time, I made a fragment, and I already use it on every page.
The problem is that the links on the page are dynamic. When the link hits the current page, its color changes, thereby showing which page the user is on.

How can I add class with color for clickable link in css according to url?

controller:

@Controller
public class HomeController {

    @GetMapping("/")
    public String home(Model model) {
        model.addAttribute("condition", "link-active");
        return "home";
    }    
}

home.html:

<!-- NAVIGATION MENU-->
    <div th:replace="fragments/navbar :: navbar">
    </div>

fragment:

<div th:fragment="navbar">
        <header class="header">
            <a class="header-logo" href="#" th:href="@{/}"><img src="/images/logo.png" alt="">
            </a>

                <ul class="header-links">
                    <li><a th:href="@{/}">Home</a></li>
                    <li><a href="#" class="link-item">Get Library<i class="fab fa-github"></i></a></li>
                    <li><a href="#" class="link-item">Examples</a></li>
                    <li><a href="#" class="link-item">Tutorials</a></li>
                </ul>

        </header>
</div>

Answer 1

Hello!
You can do this at the thymeleaf level.
Something like this should work:

<li><a href="#" class="link-item" th:classapend="${#strings.contains(#httpServletRequest.requestURI, '/tutorials')} ? colorClass : baseClass">Tutorials</a></li>

Here we get the URL from the request, check whether /tutorials is contained in the URL, and if so, then add the colorClass class, and if not, then baseClass.
Explore th:class&th:classappend

Answer 2

So far I found this solution:
Added another url for redirect in the controller:

@GetMapping("/home")
    public String home() {
        return "home";
    }

    @GetMapping("/")
    public String homePage() {
        return "forward:/home";
    }

<ul class="header-links">
            <li th:class="${#httpServletRequest.requestURI.contains('/home')} ? 'link-active' : 'link-inactive'"><a th:href="@{/home}">Home</a></li>
            <li><a href="https://github.com/tttapa/Control-Surface" target="_blank">Get Library<i class="fab fa-github"></i></a></li>
            <li th:class="${#httpServletRequest.requestURI.contains('/examples')} ? 'link-active' : 'link-inactive'"><a th:href="@{/examples}">Sketch Examples</a></li>
            <li th:class="${#httpServletRequest.requestURI.contains('/tutorials')} ? 'link-active' : 'link-inactive'"><a th:href="@{/tutorials}">Video Tutorials</a></li>
        </ul>