thymeleaf（3）自定义标签

客官°小女子只卖身不卖艺 2022-05-31 11:47 234阅读 0赞

### 1、申明自定义标签 ###

package wxtx.com.thymeleaf;
    import java.util.HashSet;
    import java.util.Set;
    import org.springframework.stereotype.Component;
    import org.thymeleaf.processor.IProcessor;
    import org.thymeleaf.spring4.dialect.SpringStandardDialect;
    
    @Component
    public class TXDialect extends SpringStandardDialect { 
        public String getPrefix() { 
            return "wxtx";
        }
        
        @Override
        public Set<IProcessor> getProcessors() { 
            final Set<IProcessor> processors = new HashSet<IProcessor>();
            processors.add(new TXElementProcessor());
            return processors;
        }
    }

import java.util.ArrayList;
    import java.util.List;
    import org.springframework.stereotype.Component;
    import org.thymeleaf.Arguments;
    import org.thymeleaf.dom.Element;
    import org.thymeleaf.dom.Node;
    import org.thymeleaf.dom.Text;
    import org.thymeleaf.processor.element.AbstractMarkupSubstitutionElementProcessor;
    
    @Component
    public class TXElementProcessor extends AbstractMarkupSubstitutionElementProcessor { 
        public TXElementProcessor() { 
            super("hello");
        }
    
        @Override
        protected List<Node> getMarkupSubstitutes(Arguments arguments, Element element) { 
        	//获取标签name属性的值
        	String name = element.getAttributeValue("name");
            List<Node> nodes = null;
        	
            if("none".equals(name)){ 
                //如果name属性的值为none,则在自定义标签下的内容前插入标签:<strong style="color:red">无信息</strong>
            	Element h2 = new Element("strong");
            	h2.setAttribute("style", "color:red");
            	h2.addChild(new Text("无信息"));
            	element.insertChild(0, h2);
            	nodes = element.getChildren();
            } else { 
                //如果name属性不为none,则移除自定义标签下的内容,插入<div>hello name</div>
                Element container = new Element("div");
                String content = "hello "+name;
                Text text = new Text(content);
                container.addChild(text);
                nodes = new ArrayList<>();
                nodes.add(container);
            }
            
            return nodes;
        }
    
        @Override
        public int getPrecedence() { 
            return 1000;
        }
    }

### 2、注册自定义标签 ###

#### 2.1、spring4 ####

修改spring配置文件

#### 2.2、springboot ####

springboot默认使用thymeleaf引擎，所以不需要在配置文件中注册自定义标签，仅需要将自定义标签类添加入spring容器即可。例如添加@Component注解。

### 3、使用方法 ###

<wxtx:hello name="小吴">123<strong>456</strong></wxtx:hello>
    <wxtx:hello name="none">123<strong>456</strong></wxtx:hello>

### 4、效果 ###

thymeleaf渲染后的html源码

<div>hello 小吴</div>
    <strong style="color:red">无信息</strong>123<strong>456</strong>

### 5、获取表达式变量 ###

[https://www.thymeleaf.org/doc/articles/sayhelloagainextendingthymeleafevenmore5minutes.html][https_www.thymeleaf.org_doc_articles_sayhelloagainextendingthymeleafevenmore5minutes.html]

[https_www.thymeleaf.org_doc_articles_sayhelloagainextendingthymeleafevenmore5minutes.html]: https://www.thymeleaf.org/doc/articles/sayhelloagainextendingthymeleafevenmore5minutes.html