Display Thymeleaf server side field validation error with bootstrap
How to display server side field validation errors with Bootstrap and Thymeleaf <form action="#" th:action="@{/}" th:object="${myForm}" method="post"> <!-- 'myform' is the form object --> <!-- start row 1 --> <div class="form row"> <!-- col 1 --> <div class="col-lg-6"> <div class="form-group"> <label th:for="*{firstname}">First name</label> <input th:field="*{firstname}" type="text" class="form-control" th:classappend="${#fields.hasErrors('firstname')}? is-invalid" <!-- adds this class in case there is a field error--> placeholder="first name" aria-describedby="firstnameFeedback"> <!-- see server-side validation from Bootstrap docs --> <div id="firstnameFeedback" th:if="${#fields.hasErrors('firstname')}" th:errors="*{firstname}" class="invalid-feedback"> <!-- is initially not displayed --> </div> </div> (...)