Creating the JSP files

Our controller configuration references three JSP files: /WEB-INF/jsp/login.jspx, /WEB-INF/jsp/welcome.jspx and /WEB-INF/jsp/goodbye.jspx.

Login page

Our login JSP page contains the form used to submit the user's id and password. Here's the JSP document: 

<jsp:root
  xmlns:jsp="http://java.sun.com/JSP/Page"
  xmlns:c="http://java.sun.com/jsp/jstl/core"
  xmlns:base="http://calyxo.odysseus.de/jsp/base"
  version="2.0">
  <jsp:directive.page contentType="text/html"/>
  <base:access var="calyxo"/>
  <html>
    <head>
      <title>Login page</title>
    </head>
    <body>
      <h3>Login, please...</h3>
      <base:form action="/login">
        <table>
          <tr>
            <td align="right">User Id</td>
            <td><input type="text" name="user"/></td>
          </tr>
          <tr>
            <td align="right">Password</td>
            <td><input type="password" name="password"/></td>
          </tr>
        </table>
        <input type="submit" value="Submit"/>
      </base:form>
      <c:if test="${!empty calyxo.control.errors}">
        <h3>Action errors</h3>
          <ul>
            <c:forEach var="message" items="${calyxo.control.errors.allMessages}">
              <li>${calyxo.base.i18n.format[message]}</li>
            </c:forEach>
          </ul>				
      </c:if>
    </body>
  </html>
</jsp:root>

The page declares the JSTL core tag library with prefix c and the Calyxo Base tag library with prefix base. The tags from that library are:

  • <base:access var="calyxo"/> This tag installs a hierarchy of accessors in request scope attribute calyxo, which can be used to navigate most of the Calyxo-related information. In our document, we use it to access and format our action error messages.
  • <base:form action="/login">...</base:form> This tag is a wrapper for the HTML form tag. It takes an action path (within the current module) as an attribute. When rendered as HTML, it converts the action path to a context-relative path selecting that action.

Welcome page

Fortunately, the welcome JSP page is much shorter. It accesses the user name from session scope and provides a link to the logout action. 

<jsp:root
  xmlns:jsp="http://java.sun.com/JSP/Page"
  xmlns:c="http://java.sun.com/jsp/jstl/core"
  xmlns:base="http://calyxo.odysseus.de/jsp/base"
  version="2.0">
  <jsp:directive.page contentType="text/html"/>
  <base:access var="calyxo"/>
  <html>
    <head>
      <title>Welcome page</title>
    </head>
    <body>
      <h3>Welcome, ${user}!</h3>
      Of cause, you can
      <c:url var="href" value="${calyxo.base.module.path['/logout']}"/>
      <a href="${href}">logout</a> again.
    </body>
  </html>
</jsp:root>

Again, this page uses the <base:access> tag. This time, it is used to construct a URL to point to the /logout action. The expression ${calyxo.base.module.path['/logout']} evaluates to the context-relative path of that action. For example, if our module uses extension mapping *.do, the result is /logout.do. If we used a prefix mapping like /main/*, the result would have been /main/login. Finally, the JSTL core <c:url> tag prepends the context name (and may do URL rewriting).

However, as shown in the logout page, there's an even easier way to link to actions using the <base:a> tag.

Goodbye page

The goodbye JSP page has nothing new. It just provides a link to login again. 

<jsp:root
  xmlns:jsp="http://java.sun.com/JSP/Page"
  xmlns:base="http://calyxo.odysseus.de/jsp/base"
  version="2.0">
  <jsp:directive.page contentType="text/html"/>
  <html>
    <head>
      <title>Goodbye page</title>
    </head>
    <body>
      <h3>Goodbye!</h3>
      Feel free to <base:a action="/index">login</base:a> again.
    </body>
  </html>
</jsp:root>

This time - as promised - we used Calyxo's <base:access> anchor tag to provide the link to our action.