Programming HTML content inside Custom Tag Handler

[Mark Reyes]

Hi All,

I started exploring using custom tags and I am trying to experiment on some of its uses.

I declared my tld as this. My goal is that using my tag, I could display any collection class as HTML List Item

<tag>
	<description>Display List Data as HTML List Item</description>
	<name>displayAsList</name>
	<tag-class>com.test.UIDisplay</tag-class>
	<body-content>scriptless</body-content>
	
	<attribute>
		<name>listData</name>
		<required>true</required>
		<rtexprvalue>true</rtexprvalue>
	</attribute>
</tag>

And use my tags like this.

<%@ taglib prefix="myTags" uri="simpleTags" %>

<div>
	<b>Products</b>
	<myTags:displayAsList listData="${packages}">List of Products</myTags:displayAsList>
</div>

The class that implements the tag is displayed below.

public class UIDisplay extends SimpleTagSupport {
	private List<String> listData;

	public void setListData(List<String> lstData) {
		this.listData = lstData;
	}

	public void doTag() throws JspException, IOException {
		JspWriter writer = getJspContext().getOut();

		if (listData == null) {
			writer.println("Unable to find List of Products!");
			throw new SkipPageException();
		}

		getJspBody().invoke(null);
		writer.print("<ul>");
		for (String strData : listData) {
			writer.print("<li>" + strData + "</li>");
		}
		writer.print("</ul>");
	}
}

But I have a query, is this the only way to accomplish this task? It is as if I am programming HTML content on my servlet?

[Bear Bibeault]

Tag files could be appropriate if you want to include JSP and HTML markup.

[Mark Reyes]

Tag files could be appropriate if you want to include JSP and HTML markup.

Ahh so thats where Tag Files really comes into the picture. Makes sense actually...

Thanks guru!

[Stefan Evans]

One comment,
You would need to declare the type of your attribute in your tld as List.
ie:

     <attribute>  
         <name>listData</name>  
         <required>true</required>  
         <rtexprvalue>true</rtexprvalue>  
         <type>java.util.List</type>
     </attribute>  

If you don't include the type tag, it will assume the default of String.