Boolean condition with Thymeleaf and Spring

Question 1

The boolean literals are true and false.

Using the th:if you will end up with a code like:

<div th:if="${isError} == true">

or if you decide to go with the th:unless

<div th:unless="${isError} == false">

There is also a #bools utility class that you can use. Please refer to the user guide: http://www.thymeleaf.org/doc/tutorials/2.1/usingthymeleaf.html#booleans

Question 2

You can access model attributes by using variable expression (${modelattribute.property}).

And, you can use th:if for conditional checking.

It looks like this:

Controller:

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MyController {

  @RequestMapping("/foo")
  public String foo(Model model) {
    Foo foo = new Foo();
    foo.setBar(true);
    model.addAttribute("foo", foo);
    return "foo";
  }

}

HTML:

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
</head>
<body>
  <div th:if="${foo.bar}"><p>bar is true.</p></div>
  <div th:unless="${foo.bar}"><p>bar is false.</p></div>
</body>
</html>

Foo.java

public class Foo {
  private boolean bar;

  public boolean isBar() {
    return bar;
  }

  public void setBar(boolean bar) {
    this.bar = bar;
  }

}

Hope this helps.