Using tags in Struts(I)

8 January 2008

Web applications differ from conventional websites in that web applications can create a dynamic response. To make it easier to reference dynamic data from a page, the Struts framework offers a set of tags. Some of the tags mimic standard HTML tag while providing added value. Other tags create non-standard, but useful controls. While HTML provides a simple a tag for creating hyperlinks, the HTML tag often requires us to include redundant information. Also the HTML tag cannot easily access dynamic data provided by the framework.

One use of the Struts Tags is to create links to other web resources, especially to other resources in the local application.

A very common use cases in web applications is linking to other pages. Let’s add a Welcome page with links to other actions.

Welcome.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
    <title>Welcome</title>
    <link href="<s:url value="/css/tutorial.css"/>" rel="stylesheet"
          type="text/css"/>
</head>
<body>
<h3>Commands</h3>
<ul>
    <li><a href="<s:url action="Register"/>">Register</a></li>
    <li><a href="<s:url action="Logon"/>">Sign On</a></li>
</ul>
</body>
</html>

Another common use case is using a link to change locales. Let’s add links to change the user’s locale and to display a message from the application resources.

HelloWorld.jsp

<body>
<h2><s:property value="message"/></h2>
 
<h3>Languages</h3>
<ul>
    <li>
        <s:url id="url" action="HelloWorld">
            <s:param name="request_locale">en</s:param>
        </s:url>
        <s:a href="%{url}">English</s:a>
    </li>
    <li>
        <s:url id="url" action="HelloWorld">
            <s:param name="request_locale">es</s:param>
        </s:url>
        <s:a href="%{url}">Espanol</s:a>
    </li>
</ul>
</body>

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