Thymeleaf快速学习笔记(一)

我会带着你远行 2022-05-20 02:04 280阅读 0赞

## 基础语法 ##

*  简单的表达式  
    Variable Expressions: $\{…\}  
    Selection Variable Expressions: \*\{…\}  
    Message Expressions: \#\{…\}  
    Link URL Expressions: @\{…\}  
    Fragment Expressions: ~\{…\}
 *  Text操作
    
    String concatenation: +  
    Literal substitutions: |The name is $\{name\}|
 *  数学操作
    
    Binary operators: +, -, \*, /, %  
    Minus sign (unary operator): -
 *  Boolean操作
    
    Binary operators: and, or  
    Boolean negation (unary operator): !, not
 *  比较操作  
    Comparators: >, <, >=, <= (gt, lt, ge, le)  
    Equality operators: ==, != (eq, ne
 *  条件操作
    
    If-then: (if) ? (then)  
    If-then-else: (if) ? (then) : (else)  
    Default: (value) ?: (defaultvalue)
    
    ## 在Thymeleaf中常见的对象 ##
    
     *  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.
    
    ## 常用的工具类 ##
    
     *  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).
    
    更多的参考文档： [说明Appendix][Appendix]
    
    ## selection object ##
    
    语法形式： \*\{firstName\}  
    含义： 操作在特定的对象上，而非基于整个context的对象  
    示例如下：

<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>

除此之外， $和\*是可以通用的…., Equivalent….

## Link URL ##

语法形式： @\{/url/xxx\}  
含义： 基于context替换为url地址  
应用范围： th:href(a)，  
示例如下：

相对的url  
\- Page-relative: user/login.html  
\- Context-relative: /itemdetails?id=3 (context name in server will be added automatically)

## Fragments ##

功能： 插入子模板信息  
应用标签: th:insert, th:replace  
示例：

## Literal 替换 ##

语法： | text, $\{var\} |  
应用说明： 字符串替代操作  
示例：

## 条件判断 ##

示例：

<tr th:class="${row.even}? (${row.first}? 'first' : 'even') : 'odd'">
      ...
    </tr>
    <tr th:class="${row.even}? 'alt'">
      ... //替换了if语言的class判断
    </tr>

这个替代了复杂的判断语句，非常简洁。

[Appendix]: https://www.thymeleaf.org/doc/tutorials/3.0/usingthymeleaf.html#appendix-b-expression-utility-objects