简单扩展让beetl HTML标签支持父子嵌套

首先看一个最终的使用效果，实现俩个html标签table.tag,tr.tag.可以在页面上这么用:

<#table data ="${userList}">
<#tr class="3c" name="name"> 名称 </#tr>
</#table>

public class HTMLNestTagSupportWrapper extends HTMLTagSupportWrapper{
public void render(){....}
}

public class TagNestContext {
private  Tag tag = null;
private TagNestContext parent = null;
private List<TagNestContext> children = null;
public  Tag getTag() {
    return tag;
}
public void setTag(Tag para) {
    this.tag = para;
}
public TagNestContext getParent() {
    return parent;
}
public void setParent(TagNestContext parent) {
    this.parent = parent;
}
public List<TagNestContext> getChildren() {
    if(children==null) children = new ArrayList<TagNestContext>();
    return children;
}
public void setChildren(List<TagNestContext> children) {
    this.children = children;
}

}

public void render()
{
    HttpServletRequest request = (HttpServletRequest)this.ctx.getGlobal("request");
    TagNestContext tnc = (TagNestContext)request.getAttribute("tagContext");
    if(tnc==null){
        tnc = new TagNestContext();
        tnc.setTag(this);
        request.setAttribute("tagContext", tnc);
        super.render();
        request.removeAttribute("tagContext");


    }else{
        TagNestContext child = new TagNestContext();
        child.setParent(tnc);
        child.setTag(this);
        tnc.getChildren().add(child);
        request.setAttribute("tagContext", child);
        super.render();
        //重新设置
        request.setAttribute("tagContext", child.getParent());

    }




}

public String getTagName(){
    return (String)this.args[0];
}

public Object get(String attr){
    Map map =  (Map)this.args[1];
    return map.get(attr);
}

<tr class="${class}">${tagBody}</tr>

<table>
${tagBody}
<% for(var item in data){%>
<tr>
<%

var tag = getTagContext();
var children = tag.children;
for(var tdTagCtx in children){
    print("<td>");
    var tdTag = tdTagCtx.tag;
    var name = tdTag.tagName;
    var value = item[name];
    print(value);
    println("</td>");
}


%>
</tr>
<%} %>
</table>

简单扩展让beetl HTML标签支持父子嵌套

原文：http://my.oschina.net/u/567839/blog/376855