Thymeleaf 3学习笔记

2024年5月13日 205次阅读 来源: xbynet

Thymeleaf 目前最新版本3.0
Thymeleaf作为Spring-Boot官方推荐模板引擎，而且支持纯HTML浏览器展现(模板表达式在脱离运行环境下不污染html结构).是时候了解一番了。

安装与初始化配置

与Spring集成

<dependency>
  <groupId>org.thymeleaf</groupId>
  <artifactId>thymeleaf-spring4</artifactId>
  <version>3.0.0.RELEASE</version>
</dependency>

与Spring-Boot集成：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

在Spring中进行配置：

@Configuration
@EnableWebMvc
@ComponentScan("com.thymeleafexamples")
public class ThymeleafConfig extends WebMvcConfigurerAdapter implements ApplicationContextAware {

  private ApplicationContext applicationContext;

  public void setApplicationContext(ApplicationContext applicationContext) {
    this.applicationContext = applicationContext;
  }

  @Bean
  public ViewResolver viewResolver() {
    ThymeleafViewResolver resolver = new ThymeleafViewResolver();
    resolver.setTemplateEngine(templateEngine());
    resolver.setCharacterEncoding("UTF-8");
    return resolver;
  }

  @Bean
  public TemplateEngine templateEngine() {
    SpringTemplateEngine engine = new SpringTemplateEngine();
    engine.setEnableSpringELCompiler(true);
    engine.setTemplateResolver(templateResolver());
    return engine;
  }

  private ITemplateResolver templateResolver() {
    SpringResourceTemplateResolver resolver = new SpringResourceTemplateResolver();
    resolver.setApplicationContext(applicationContext);
    resolver.setPrefix("/WEB-INF/templates/");
    resolver.setTemplateMode(TemplateMode.HTML);
    return resolver;
  }
}

在Spring-Boot中只需如下配置：

#thymeleaf start
spring.thymeleaf.mode=HTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.content-type=text/html
#开发时关闭缓存,不然没法看到实时页面
spring.thymeleaf.cache=false
#thymeleaf end

具体可以配置的参数可以查看 org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties这个类,上面的配置实际上就是注入到该类中的属性值.

基本语法

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>hello</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<!--/*@thymesVar id="name" type="java.lang.String"*/-->
<p th:text="'Hello！, ' + ${name} + '!'" >3333</p>
</body>
</html>

表达式

  • Variable Expressions: ${…}

  • Selection Variable Expressions: *{…}

  • Message Expressions: #{…}

  • Link URL Expressions: @{…}

  • Fragment Expressions: ~{…}

字符串操作:

  • String concatenation: +

  • Literal substitutions: |The name is ${name}|

条件操作：

  • If-then: (if) ? (then)

  • If-then-else: (if) ? (then) : (else)

  • Default: (value) ?: (defaultvalue)

  • No-Operation: _

如：'User is of type ' + (${user.isAdmin()} ? 'Administrator' : (${user.type} ?: 'Unknown'))

1、获取变量值

<p th:text="'Hello！, ' + ${name} + '!'" >3333</p>

可以看出获取变量值用$符号,对于javaBean的话使用变量名.属性名方式获取,这点和EL表达式一样.另外$表达式只能写在th标签内部,不然不会生效
#{}是国际化支持取值的符号
注意:th:text与th:utext的区别，输出中文时应该使用th:utext
${..}实际语法是:OGNL(非web),SpEL(web) ,支持的内置变量

便捷部分

  • ${x} will return a variable x stored into the Thymeleaf context or as a request attribute.

  • ${param.x} will return a request parameter called x (which might be multivalued).

  • ${session.x} will return a session attribute called x.

  • ${application.x} will return a servlet context attribute called x.

基本的

#ctx: the context object.
#vars: the context variables.
#locale: the context locale.
#request: (only in Web Contexts) the HttpServletRequest object.
#response: (only in Web Contexts) the HttpServletResponse object.
#session: (only in Web Contexts) the HttpSession object.
#servletContext: (only in Web Contexts) the ServletContext object.

工具对象

#execInfo: information about the template being processed.
#messages: methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
#uris: methods for escaping parts of URLs/URIs
#conversions: methods for executing the configured conversion service (if any).
#dates: methods for java.util.Date objects: formatting, component extraction, etc.
#calendars: analogous to #dates, but for java.util.Calendar objects.
#numbers: methods for formatting numeric objects.
#strings: methods for String objects: contains, startsWith, prepending/appending, etc.
#objects: methods for objects in general.
#bools: methods for boolean evaluation.
#arrays: methods for arrays.
#lists: methods for lists.
#sets: methods for sets.
#maps: methods for maps.
#aggregates: methods for creating aggregates on arrays or collections.
#ids: methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).

工具对象的使用方式见：http://www.thymeleaf.org/doc/…， 以下仅仅举几个例子

${#dates.format(date, 'dd/MMM/yyyy HH:mm')}
${#dates.arrayFormat(datesArray, 'dd/MMM/yyyy HH:mm')}
${#dates.listFormat(datesList, 'dd/MMM/yyyy HH:mm')}
${#dates.setFormat(datesSet, 'dd/MMM/yyyy HH:mm')}
${#dates.createNow()}
${#dates.createToday()} //time set to 00:00

${#strings.isEmpty(name)}  //Check whether a String is empty (or null)
${#strings.arrayIsEmpty(nameArr)}
${#strings.listIsEmpty(nameList)}
${#strings.setIsEmpty(nameSet)} 

${#strings.startsWith(name,'Don')}                  // also array*, list* and set*
${#strings.endsWith(name,endingFragment)}           // also array*, list* and set*

${#strings.length(str)}
${#strings.equals(str)}
${#strings.equalsIgnoreCase(str)}
${#strings.concat(str)}
${#strings.concatReplaceNulls(str)}

用*{...} 选择对象里的变量，如

<div th:object="${session.user}">
    <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
    <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p>
    <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
  </div>

//等价于
<div>
  <p>Name: <span th:text="${session.user.firstName}">Sebastian</span>.</p>
  <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
  <p>Nationality: <span th:text="${session.user.nationality}">Saturn</span>.</p>
</div>

字面量

  • Text literals: ‘one text’, ‘Another one!’,…

  • Number literals: 0, 34, 3.0, 12.3,…

  • Boolean literals: true, false

  • Null literal: null

字符串一般需要包围在’单引号内，但也有几种变通方式

<div th:class="'content'">...</div>
<span th:text="|Welcome to our application, ${user.name}!|">
//Which is equivalent to:
<span th:text="'Welcome to our application, ' + ${user.name} + '!'">
<span th:text="${onevar} + ' ' + |${twovar}, ${threevar}|">

定义模板本地变量

<div th:with="firstPer=${persons[0]}">
  <p>
    The name of the first person is <span th:text="${firstPer.name}">Julius Caesar</span>.
  </p>
</div>
<div th:with="firstPer=${persons[0]},secondPer=${persons[1]}">
  <p>
    The name of the first person is <span th:text="${firstPer.name}">Julius Caesar</span>.
  </p>
  <p>
    But the name of the second person is 
    <span th:text="${secondPer.name}">Marcus Antonius</span>.
  </p>
</div>

2.引入URL
Thymeleaf对于URL的处理是通过语法@{…}来处理的

<a th:href="@{http://blog.csdn.net/u012706811}">绝对路径</a>
<a th:href="@{/}">相对路径</a>
<a th:href="@{css/bootstrap.min.css}">Content路径,默认访问static下的css文件夹</a>

类似的标签有:th:href和th:src

<!-- Will produce 'http://localhost:8080/gtvg/order/details?orderId=3' (plus rewriting) -->
<a href="details.html" 
   th:href="@{http://localhost:8080/gtvg/order/details(orderId=${o.id})}">view</a>

<!-- Will produce '/gtvg/order/details?orderId=3' (plus rewriting) -->
<a href="details.html" th:href="@{/order/details(orderId=${o.id})}">view</a>

<!-- Will produce '/gtvg/order/3/details' (plus rewriting) -->
<a href="details.html" th:href="@{/order/{orderId}/details(orderId=${o.id})}">view</a>

<a th:href="@{${url}(orderId=${o.id})}">view</a>
<a th:href="@{'/details/'+${user.login}(orderId=${o.id})}">view</a>

Server root relative URLs
An additional syntax can be used to create server-root-relative (instead of context-root-relative) URLs in order to link to different contexts in the same server. These URLs will be specified like @{~/path/to/something}

3、运算符
在表达式中可以使用各类算术运算符，例如+, -, *, /, %

th:with="isEven=(${prodStat.count} % 2 == 0)"

逻辑运算符>, <, >=, <=，==,!= (gt, lt, ge, le,eq,ne)都可以使用，唯一需要注意的是使用<,>时需要用它的HTML转义符：

th:if="${prodStat.count} &gt; 1"
th:text="'Execution mode is ' + ( (${execMode} == 'dev')? 'Development' : 'Production')"

布尔运算符: and or not/!

4.条件
if/unless
Thymeleaf中使用th:if和th:unless属性进行条件判断，标签只有在th:if中条件成立时才显示,th:unless于th:if恰好相反，只有表达式中的条件不成立，才会显示其内容。

<a th:href="@{/login}" th:unless=${session.user != null}>Login</a>

Switch
Thymeleaf同样支持多路选择Switch结构,默认属性default可以用*表示:

<div th:switch="${user.role}">
  <p th:case="'admin'">User is an administrator</p>
  <p th:case="#{roles.manager}">User is a manager</p>
  <p th:case="*">User is some other thing</p>
</di

5.循环

<tr th:each="prod : ${prods}">
      <td th:text="${prod.name}">Onions</td>
      <td th:text="${prod.price}">2.41</td>
      <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
    </tr>

迭代对象必须为

  • Any object implementing java.util.Iterable、 java.util.Enumeration、java.util.Iterator

  • Any object implementing java.util.Map. When iterating maps, iter variables will be of class java.util.Map.Entry.

  • Any array.

  • Any other object will be treated as if it were a single-valued list containing the object itself.

<tr th:each="prod,iterStat : ${prods}" th:class="${iterStat.odd}? 'odd'">
    <td th:text="${prod.name}">Onions</td>
    <td th:text="${prod.price}">2.41</td>
    <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
  </tr>
//不过也可以直接加Stat后缀访问状态变量
<tr th:each="prod : ${prods}" th:class="${prodStat.odd}? 'odd'">
    <td th:text="${prod.name}">Onions</td>
    <td th:text="${prod.price}">2.41</td>
    <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
  </tr>

th:each内置迭代状态属性：

  • index ,当前索引，从0开始。

  • count,当前数目，从1开始。

  • size，总大小

  • current，当前值

  • even/odd boolean properties.

  • first boolean property.

  • last boolean property.

6、设置html标签属性

<img src="../../images/gtvglogo.png" 
     th:attr="src=@{/images/gtvglogo.png},title=#{logo},alt=#{logo}" />
//which is equivalent:
<img src="../../images/gtvglogo.png" 
     th:src="@{/images/gtvglogo.png}" th:title="#{logo}" th:alt="#{logo}" />

//append
<tr th:each="prod : ${prods}" class="row" th:classappend="${prodStat.odd}? 'odd'">

Thymeleaf 3中的一些变化和特性

  1. 模板变化
    推荐你去掉模板中的 th:inline=“text” 属性。因为在HTML或XML模板中，不再需要该属性去支持文本中内联表达式的特性。

  2. 完整的HTML5 标记支持
    不在强制要求标签闭合，属性加引号等等

  3. 模板类型
    Thymeleaf 3 移除了之前版本的模板类型，新的模板类型为：HTML、XML、TEXT、JAVASCRIPT、CSS、RAW

文本型模板
文本型模板使得Thymeleaf可以支持输出CSS、Javascript和文本文件。在你想要在CSS或Javascript文件中使用服务端的变量时；或者想要输出纯文本的内容时。
在文本模式中使用Thymeleaf的特性，你需要使用一种新的语法，例如：

[# th:each="item : ${items}"]
  - [# th:utext="${item}" /]
[/]
var a = [# th:text="${msg}"/];

增强的内联机制
现在可无需额外的标签，直接在文本中输出数据：

This product is called [[${product.name}]] and it's great!
var a = [[${msg}]];

4、片段（Fragment）表达式

Thymeleaf 3.0 引入了一个新的片段表达式。形如：~{commons::footer}。
该特性十分有用（比如解决定义通用的header和footer的问题）
base.html

<head th:fragment="common_header(title,links)">
  <title th:replace="${title}">The awesome application</title>

  <!-- Common styles and scripts -->
  <link rel="stylesheet" type="text/css" media="all" th:href="@{/css/awesomeapp.css}">
  <link rel="shortcut icon" th:href="@{/images/favicon.ico}">
  <script type="text/javascript" th:src="@{/sh/scripts/codebase.js}"></script>

  <!--/* Per-page placeholder for additional links */-->
  <th:block th:replace="${links}" />

</head>

main.html

<head th:replace="base :: common_header(~{::title},~{::link})">
  <title>Awesome - Main</title>
  <link rel="stylesheet" th:href="@{/css/bootstrap.min.css}">
  <link rel="stylesheet" th:href="@{/themes/smoothness/jquery-ui.css}">
</head>

片段经常和th:insert or th:replace一起使用

<div th:insert="~{commons :: main}">...</div>

<div th:with="frag=~{footer :: #main/text()}">
  <p th:insert="${frag}">
</div>

~{::selector} or ~{this::selector}引用本模板内的片段

不使用th:fragment定义的片段的情况：

<div id="copy-section">
  &copy; 2011 The Good Thymes Virtual Grocery
</div>
 <div th:insert="~{footer :: #copy-section}"></div>

th:insert and th:replace (and th:include)的区别：

  • th:insert 插入片段本身

  • th:replace actually replaces its host tag with the specified fragment.

  • th:include 与th:insert不同的是，它插入的是片段解析后的内容

5、无操作标记（token）
Thymeleaf 3.0 另一个新的特性就是无操作（NO-OP no-operation）标记，下划线”_”，代表什么也不做。
例如：
<span th:text="${user.name} ?: _">no user authenticated</span>
当user.name 为空的时候，直接输出标签体中的内容

注释

普通html注释：<!– User info follows –>
Thymeleaf 注释：

1、<!--/* This code will be removed at Thymeleaf parsing time! */-->

2、<!--/*--> 
  <div>
     you can see me only before Thymeleaf processes me!
  </div>
<!--*/-->

3、<!--/*/
  <div th:text="${...}">
    ...
  </div>
/*/-->

html内联

//不会转义时
<p>The message is "[(${msg})]"</p>
//等价于
<p>The message is "This is <b>great!</b>"</p>

//转义时
<p>The message is "[[${msg}]]"</p>
//等价于
<p>The message is "This is &lt;b&gt;great!&lt;/b&gt;"</p>

//禁用内联
<p th:inline="none">A double array looks like this: [[1, 2, 3], [4, 5]]!</p>

//js内联
<script th:inline="javascript">
    ...
    var username = [[${session.user.name}]];
    ...
</script>


//css内联
<style th:inline="css">
    .[[${classname}]] {
      text-align: [[${align}]];
    }
</style>

Markup Selector Syntax

http://www.thymeleaf.org/doc/…

demo:

参考：
http://www.thymeleaf.org/doc/…
http://www.thymeleaf.org/doc/…
http://blog.csdn.net/u0127068…
https://www.tianmaying.com/tu…
http://www.thymeleaf.org/doc/…

    原文作者：xbynet
    原文地址: https://segmentfault.com/a/1190000009903821
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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