Thymeleaf - 조건부 평가

Thymeleaf/Thymeleaf - 기본기능

Thymeleaf - 조건부 평가

진이최고다 2023. 4. 3. 12:52

조건부 평가

if , unless(if 의 반대)

예제

Controller

    @GetMapping("/condition")
    public String condition(Model model) {
        addUsers(model);
        return "basic/condition";
    }

    private void addUsers(Model model) {
        List<User> list = new ArrayList<>();
        list.add(new User("UserA", 10));
        list.add(new User("UserB", 20));
        list.add(new User("UserC", 30));

        model.addAttribute("users",list);
    }

    @Data
    static class User {
        private String username;
        private int age;

        public User(String username, int age) {
            this.username = username;
            this.age = age;
        }
    }

View

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>if, unless</h1>
<table border="1">
    <tr>
        <th>count</th>
        <th>username</th>
        <th>age</th>
    </tr>
    <tr th:each="user, userStat : ${users}">
        <td th:text="${userStat.count}">1</td>
        <td th:text="${user.username}">username</td>
        <td>
            <span th:text="${user.age}">0</span>
            <span th:text="'미성년자'" th:if="${user.age lt 20}"></span>
            <span th:text="'미성년자'" th:unless="${user.age ge 20}"></span>
        </td>
    </tr>
</table>
<h1>switch</h1>
<table border="1">
    <tr>
        <th>count</th>
        <th>username</th>
        <th>age</th>
    </tr>
    <tr th:each="user, userStat : ${users}">
        <td th:text="${userStat.count}">1</td>
        <td th:text="${user.username}">username</td>
        <td th:switch="${user.age}">
            <span th:case="10">10살</span>
            <span th:case="20">20살</span>
            <span th:case="*">기타</span>
        </td>
    </tr>
</table>
</body>
</html>

👇페이지 소스

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>if, unless</h1>
<table border="1">
    <tr>
        <th>count</th>
        <th>username</th>
        <th>age</th>
    </tr>
    <tr>
        <td>1</td>
        <td>UserA</td>
        <td>
            <span>10</span>
            <span>미성년자</span>
            <span>미성년자</span>
        </td>
    </tr>
    <tr>
        <td>2</td>
        <td>UserB</td>
        <td>
            <span>20</span>
            
            
        </td>
    </tr>
    <tr>
        <td>3</td>
        <td>UserC</td>
        <td>
            <span>30</span>
            
            
        </td>
    </tr>
</table>
<h1>switch</h1>
<table border="1">
    <tr>
        <th>count</th>
        <th>username</th>
        <th>age</th>
    </tr>
    <tr>
        <td>1</td>
        <td>UserA</td>
        <td>
            <span>10살</span>
            
            
        </td>
    </tr>
    <tr>
        <td>2</td>
        <td>UserB</td>
        <td>
            
            <span>20살</span>
            
        </td>
    </tr>
    <tr>
        <td>3</td>
        <td>UserC</td>
        <td>
            
            
            <span>기타</span>
        </td>
    </tr>
</table>
</body>
</html>

✏️if, unless
타임리프는 해당 조건이 맞지 않으면 태그 자체를 렌더링하지 않는다.
만약 다음 조건이 false 인 경우 <span>...<span> 부분 자체가 렌더링 되지 않고 사라진다.
<span th:text="'미성년자'" th:if="${user.age lt 20}"></span>

✏️switch
* 은 만족하는 조건이 없을 때 사용하는 디폴트이다.

인프런 김영한님의 Sping강의 기반으로 공부한 것을 작성한 블로그입니다.
출처 : 인프런 -🔗 스프링 MVC 1편 by 우아한형제 김영한이사님