How can a parent tag access its child tag's attribute in Simple Tag

[Tony suankularb]

I know only how parent tag access its child tag's attribute in Classic Tag

Source code from HFSJ

JSP

    
<mine:Menu >
     <mine:MenuItem itemValue=”Dogs” />
</mine:Menu>

child tag: MenuItem

    
public class MenuItem extends TagSupport {
private String itemValue;

 public void setItemValue(String value) {
       itemValue=value;
}

public int doStartTag() throws JspException {
       return EVAL_BODY_INCLUDE;
}

public int doEndTag() throws JspException {
      Menu parent = (Menu) getParent();
      parent.addMenuItem(itemValue);
     return EVAL_PAGE;
}
}

In the parent tag: Menu

    
public class Menu extends TagSupport {
private ArrayList items;

public void addMenuItem(String item) {
     items.add(item);
}

public int doStartTag() throws JspException {
     items = new ArrayList();
     return EVAL_BODY_INCLUDE;
}

public int doEndTag() throws JspException {
try {
      pageContext.getOut().println(“Menu items are: “ + items);
} catch(Exception ex) {
      throw new JspException(“Exception: “ + ex.toString());
}

     return EVAL_PAGE;
}
}

As far as I understand, the body content is evaluated between doStartTag() and doEndTag().
So, doEndTag() can access its child's attribute.



But, what about Simple Handler Class which has only doTag() method
How can we know the child's attribute is available for the parent. I means in the simple tag, when the body content is evaluated.

All I know is getJspBody().invoke(writer); of Simple Tag can write the body to a writer

[Chinmaya Chowdary]

Hi, Tony.

Modify Menu.java and MenuItem.java as,

Menu.java

    public class Menu extends SimpleTagSupport{
   private ArrayList items;
   public void addMenuItem(String item)
   {
       items.add(item);
   }
   
   public void doTag() throws JspException, IOException{
	   items=new ArrayList();
	  
   getJspBody().invoke(null);
   getJspContext().getOut().print("Menu items are: "+items);
   
   }
   }

and MenuItem.java

    public class MenuItem extends SimpleTagSupport
   {
	   private String itemValue;
	   public void setItemValue(String value){
	   itemValue=value;
	   }
	   
	   public void doTag() throws JspException,IOException{
		  
	   Menu parent = (Menu) getParent();
	   parent.addMenuItem(itemValue);
	   
	   }
   }

[Tony suankularb]

Thanks a lot , Chinmaya