Thymeleaf快速学习笔记(一)

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

  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：

<a href="details.html" th:href="@{/order/{orderId}/details(orderId=${o.id})}">view</a>

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：

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

Literal 替换

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

<span th:text="|Welcome to our application, ${user.name}!|">
等同于：
<span th:text="'Welcome to our application, ' + ${user.name} + '!'">

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。