Spring4 + Thymeleaf3 Form Validation : bean name #fields not available in templates - spring

Question

I get the below error in my spring4 + thymeleaf3 application when I try to show validation errors in my form template.
Neither BindingResult nor plain target object for bean name '#fields' available as request attribute
My form is as below.
<form th:action="#{/user/save}" method="post" th:object="${user}">
<ul th:if="${#fields.hasErrors()}">
<li th:each="err : ${#fields.errors('*')}" th:text="${err}"></li>
</ul>
<div>
<label>Name</label>
<div>
<input type="text" th:field="*{firstName}" placeholder="First Name">
<input type="text" th:field="*{lastName}" placeholder="Last Name">
<div th:if="${#fields.hasErrors('firstName')}" th:errors="${#fields.errors('firstName')}"></div>
<div th:if="${#fields.hasErrors('lastName')}" th:errors="${#fields.errors('lastName')}"></div>
</div>
</div>...
The form is rendered well for the following get request mapping.
#GetMapping("/create")
public String create(ModelMap model) {
model.put("user", new User());
return VIEW_DIR.concat("form");
}
But it gives the above error when the form is submitted with some invalid fields to the following method.
#PostMapping("/save")
public String save(#Valid User user, BindingResult bindingResult, ModelMap model) {
if(bindingResult.hasErrors()) {
return VIEW_DIR.concat("form");
}
userService.save(user);
return "redirect:list";
}
Can you please show me where the error is.

Answer 1

You are setting wrong values for th:errors inside your form element div. th:errors should contain field name. Update your form with this:
<div>
<input type="text" th:field="*{firstName}" placeholder="First Name">
<input type="text" th:field="*{lastName}" placeholder="Last Name">
<div th:if="${#fields.hasErrors('firstName')}" th:errors="*{firstName}"></div>
<div th:if="${#fields.hasErrors('lastName')}" th:errors="*{lastName}"></div>
</div>