SpringBoot

37.SpringBoot学习笔记

CRUD实验--员工列表-公共页抽取

Posted by Chen Xingxu on June 20, 2020

37.SpringBoot学习笔记–CRUD实验–员工列表-公共页抽取

查询员工列表

Controller 层

demo.yangxu.springboot.controller.EmployeeController

package demo.yangxu.springboot.controller;

import demo.yangxu.springboot.dao.EmployeeDao;
import demo.yangxu.springboot.entities.Employee;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

import java.util.Collection;

@Controller
public class EmployeeController {

    @Autowired
    EmployeeDao employeeDao;

    //查询所有员工返回列表页面
    @GetMapping("/emps")
    public String list(Model model){
        Collection<Employee> employees = employeeDao.getAll();
        //放在请求域中
        model.addAttribute("emps",employees);
        // thymeleaf默认就会拼串
        // classpath:/templates/xxxx.html
        return "/emp/list";
    }
}

thymeleaf 公共页面元素抽取

1、抽取公共片段

In our templates, we will often want to include parts from other templates, parts like footers, headers, menus…

In order to do this, Thymeleaf needs us to define these parts, “fragments”, for inclusion, which can be done using the th:fragment attribute.

Say we want to add a standard copyright footer to all our grocery pages, so we create a /WEB-INF/templates/footer.html file containing this code:

<!DOCTYPE html>

<html xmlns:th="http://www.thymeleaf.org">

  <body>
  
    <div th:fragment="copy">
      &copy; 2011 The Good Thymes Virtual Grocery
    </div>
  
  </body>
  
</html>

2、引入公共片段

The code above defines a fragment called copy that we can easily include in our home page using one of the th:insert or th:replace attributes (and also th:include, though its use is no longer recommended since Thymeleaf 3.0):

<body>

  ...

  <div th:insert="~{footer :: copy}"></div>
  
</body>

Note that th:insert expects a fragment expression (~{...}), which is an expression that results in a fragment. In the above example though, which is a non-complex fragment expression, the (~{,}) enclosing is completely optional, so the code above would be equivalent to:

<body>

  ...

  <div th:insert="footer :: copy"></div>
  
</body>

"~{templatename::selector}" Includes the fragment resulting from applying the specified Markup Selector on the template named templatename. Note that selector can be a mere fragment name, so you could specify something as simple as ~{templatename::fragmentname} like in the ~{footer :: copy} above.

Referencing fragments without th:fragment

Thanks to the power of Markup Selectors, we can include fragments that do not use any th:fragment attributes. It can even be markup code coming from a different application with no knowledge of Thymeleaf at all:

...
<div id="copy-section">
  &copy; 2011 The Good Thymes Virtual Grocery
</div>
...

We can use the fragment above simply referencing it by its id attribute, in a similar way to a CSS selector:

<body>

  ...

  <div th:insert="~{footer :: #copy-section}"></div>
  
</body>

3、默认效果 insert 的公共片段在 div 标签中 如果使用 th:insert 等属性进行引入，可以不用写 ~{}： 行内写法可以加上：[[~{}]];[(~{})]；

4、三种引入公共片段的 th 属性

th:insert：将公共片段整个插入到声明引入的元素中

th:replace：将声明引入的元素替换为公共片段

th:include：将被引入的片段的内容包含进这个标签中

And what is the difference between th:insert and th:replace (and th:include, not recommended since 3.0)?

  • th:insert is the simplest: it will simply insert the specified fragment as the body of its host tag.
  • th:replace actually replaces its host tag with the specified fragment.
  • th:include is similar to th:insert, but instead of inserting the fragment it only inserts the contents of this fragment.

So an HTML fragment like this:

<footer th:fragment="copy">
  &copy; 2011 The Good Thymes Virtual Grocery
</footer>

…included three times in host `` tags, like this:

<body>

  ...

  <div th:insert="footer :: copy"></div>

  <div th:replace="footer :: copy"></div>

  <div th:include="footer :: copy"></div>
  
</body>

…will result in:

<body>

  ...

  <div>
    <footer>
      &copy; 2011 The Good Thymes Virtual Grocery
    </footer>
  </div>

  <footer>
    &copy; 2011 The Good Thymes Virtual Grocery
  </footer>

  <div>
    &copy; 2011 The Good Thymes Virtual Grocery
  </div>
  
</body>

参考：

8 Template Layout

Difference between th:insert and th:replace (and th:include)

Referencing fragments without th:fragment

应用到项目中

1、抽取 templates\dashboard.html 的顶部栏和侧边栏

顶部标签：

<nav class="navbar navbar-dark sticky-top bg-dark flex-md-nowrap p-0" th:fragment="topbar">
    <a class="navbar-brand col-sm-3 col-md-2 mr-0" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">[[${session.loginUser}]]</a>
    <input class="form-control form-control-dark w-100" type="text" placeholder="Search" aria-label="Search">
    <ul class="navbar-nav px-3">
        <li class="nav-item text-nowrap">
            <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">Sign out</a>
        </li>
    </ul>
</nav>

侧边标签：

<nav class="col-md-2 d-none d-md-block bg-light sidebar" id="sidebar">
    <div class="sidebar-sticky">
        <ul class="nav flex-column">
            <li class="nav-item">
                <a class="nav-link active" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-home">
                        <path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path>
                        <polyline points="9 22 9 12 15 12 15 22"></polyline>
                    </svg>
                    Dashboard <span class="sr-only">(current)</span>
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-file">
                        <path d="M13 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V9z"></path>
                        <polyline points="13 2 13 9 20 9"></polyline>
                    </svg>
                    Orders
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-shopping-cart">
                        <circle cx="9" cy="21" r="1"></circle>
                        <circle cx="20" cy="21" r="1"></circle>
                        <path d="M1 1h4l2.68 13.39a2 2 0 0 0 2 1.61h9.72a2 2 0 0 0 2-1.61L23 6H6"></path>
                    </svg>
                    Products
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#" th:href="@{/emps}">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-users">
                        <path d="M17 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2"></path>
                        <circle cx="9" cy="7" r="4"></circle>
                        <path d="M23 21v-2a4 4 0 0 0-3-3.87"></path>
                        <path d="M16 3.13a4 4 0 0 1 0 7.75"></path>
                    </svg>
                    员工管理
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-bar-chart-2">
                        <line x1="18" y1="20" x2="18" y2="10"></line>
                        <line x1="12" y1="20" x2="12" y2="4"></line>
                        <line x1="6" y1="20" x2="6" y2="14"></line>
                    </svg>
                    Reports
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-layers">
                        <polygon points="12 2 2 7 12 12 22 7 12 2"></polygon>
                        <polyline points="2 17 12 22 22 17"></polyline>
                        <polyline points="2 12 12 17 22 12"></polyline>
                    </svg>
                    Integrations
                </a>
            </li>
        </ul>

        <h6 class="sidebar-heading d-flex justify-content-between align-items-center px-3 mt-4 mb-1 text-muted">
<span>Saved reports</span>
<a class="d-flex align-items-center text-muted" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-plus-circle"><circle cx="12" cy="12" r="10"></circle><line x1="12" y1="8" x2="12" y2="16"></line><line x1="8" y1="12" x2="16" y2="12"></line></svg>
</a>
</h6>
        <ul class="nav flex-column mb-2">
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-file-text">
                        <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path>
                        <polyline points="14 2 14 8 20 8"></polyline>
                        <line x1="16" y1="13" x2="8" y2="13"></line>
                        <line x1="16" y1="17" x2="8" y2="17"></line>
                        <polyline points="10 9 9 9 8 9"></polyline>
                    </svg>
                    Current month
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-file-text">
                        <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path>
                        <polyline points="14 2 14 8 20 8"></polyline>
                        <line x1="16" y1="13" x2="8" y2="13"></line>
                        <line x1="16" y1="17" x2="8" y2="17"></line>
                        <polyline points="10 9 9 9 8 9"></polyline>
                    </svg>
                    Last quarter
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-file-text">
                        <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path>
                        <polyline points="14 2 14 8 20 8"></polyline>
                        <line x1="16" y1="13" x2="8" y2="13"></line>
                        <line x1="16" y1="17" x2="8" y2="17"></line>
                        <polyline points="10 9 9 9 8 9"></polyline>
                    </svg>
                    Social engagement
                </a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">
                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-file-text">
                        <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path>
                        <polyline points="14 2 14 8 20 8"></polyline>
                        <line x1="16" y1="13" x2="8" y2="13"></line>
                        <line x1="16" y1="17" x2="8" y2="17"></line>
                        <polyline points="10 9 9 9 8 9"></polyline>
                    </svg>
                    Year-end sale
                </a>
            </li>
        </ul>
    </div>
</nav>

2、应用到 templates\emp\list.html

顶部栏

<!--引入抽取的topbar-->
<!--模板名：会使用thymeleaf的前后缀配置规则进行解析-->
<div th:replace="dashboard::topbar"></div>

侧边栏

<!-- 引入侧边栏 -->
<div th:replace="~{dashboard::#sidebar}"></div>
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