TilesAction, how to???

[Leandro Melo]

Can anyone give me an example of how to use TilesAction to dinamically modify a definition???

Or maybe, some other way to dinamically modify a definition...?

Suppose, for example

   <definition name=".PartyPlace" path="/layouts/layout.jsp">
      ...
        <put name="menu" value="/common/menu.jsp"/>
        ...
   </definition>

I need to change from menu.jsp to menu2.jsp depending on the user logged. So i need to change this base definition.

I heard you can do do something like that.

   <definition name=".PartyPlace" path="/layouts/layout.jsp">
      ...
        <put name="menu" value="/changeMenu.do"/>
        ...
   </definition>

Where changeMenu.do is a TilesAction that can access the attributes of the definition.

Any help would be great!

[Anthony Watson]

Why don't you just return a different forward from your action, depending on the type of user logged in? Each forward could be mapped to a different tile.

[Leandro Melo]

That's not what i want.

There's no motive to have diferent definitions where the pages only differ by the menu.
It's a lot more reasonable to change the menu of the definition depending on the user logged in.

Here's some interesting stuff i found.
http://www.junlu.com/msg/45975.html
[ August 16, 2004: Message edited by: Leandro Melo ]

[Anthony Watson]

I don't know how to do it like you are talking about, but its not a big deal to create a second definition that inherits from the first and overrides the menu.jsp value and doesn't specify any other values.

[Leandro Melo]

Suppose then that it's a base definition.
I'm gonna have to duplicate all definitions i have (i'm gonna have 2 types of definitions, the ones that extend from def1 and the other ones that extend from def2) just because of a menu.
Changing wich menu should be displayed dinamically, all other children definitions of the application are already usable.
Think of how bad it would be keeping forwarding to 3 o 4 definitions (supposing i got 3 or 4 diferent menus) that are composed by the exactly same stuff just because of a menu. It's such a bad architecture.

[Anthony Watson]

I did't realize at first that your menu would be on every page. You're right, it sounds like you do need to go another route than what I suggested. Good luck. If you get that TilesAction thing to work, I'd love to see an example of it posted here.

[Sree Jag]

hi Leandro,

I had the same requirement too. I did something like this:

<logic:equal name="type" value="HS">
<tiles:insert attribute="styleNavigation"/>
</logic:equal>

<logic:equal name="type" value="HR">
<tiles:insert attribute="navigationRegular"/>
</logic:equal>

where these two attributes are defined in your tiles definition.
i.e i just passed some parameters to the root layout definition JSP


this may not be the exact way u r looking for or i am being too simplistic.

Seshu

[Anthony Watson]

Good news, I figured out how to do what you want, using the method you requested, the TilesAction way. You basically create a new class that can dynamically change your tiles and then tell the definition to look for it before it is displayed.

Below is the code. All you need to do is to change the code in the DynamicTileController to check to see if the user has logged in before you change the menu.

tiles-defs.xml

  
   <!--Best way because it calls execute method on DynamicTileController-->
    <definition name=".base" path="/WEB-INF/tiles/layouts/base.jsp"
                controllerUrl="/dynamicTileController.do">
        <put name="header"       value="/WEB-INF/tiles/header.jsp" />
        <!-- must supply body-->
        <put name="footer"       value="/WEB-INF/tiles/footer.jsp" />
    </definition>
 
    <!--Works but not best way because it calls perform method on DynamicTileController-->
    <!--
    <definition name=".base" path="/WEB-INF/tiles/layouts/base.jsp"
                controllerClass="com.realink.dynamicTileTest.DynamicTileController">
        <put name="header"       value="/WEB-INF/tiles/header.jsp" />
        <put name="footer"       value="/WEB-INF/tiles/footer.jsp" />
    </definition>
    -->
 
    <definition name=".page1" extends=".base">
        <put name="body"         value="/WEB-INF/pages/loginBody.jsp" />
    </definition>
 
    <definition name=".page2" extends=".base">
        <put name="body"         value="/WEB-INF/pages/page2.jsp" />
    </definition>

struts-config.xml

  
    <action type="org.apache.struts.actions.ForwardAction" 
            unknown="true"  
            parameter=".page1" 
            path="/page1">
    </action>
    
    <action type="org.apache.struts.actions.ForwardAction" 
            parameter=".page2" 
            path="/page2">
    </action>
 
    <action type="com.realink.dynamicTileTest.DynamicTileController" 
            path="/dynamicTileController">
    </action>

DynamicTileController.java

  
package com.realink.dynamicTileTest;
 
import org.apache.struts.tiles.Controller;
import org.apache.struts.tiles.actions.TilesAction;
import org.apache.struts.tiles.ComponentContext;
import org.apache.struts.action.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.commons.logging.*;
 
public class DynamicTileController extends TilesAction implements Controller {
 
    Log l = LogFactory.getLog(this.getClass());
 
    //This method comes from Controller interface. It gets called when you specify a 
    //'controllerClass' attribute in a tiles definition
    public void perform(ComponentContext tileContext, HttpServletRequest request,
        HttpServletResponse response, ServletContext servletContext) throws ServletException,
        IOException {
        
        l.info("***perform method called from Controller interface");
        
        ComponentContext context = ComponentContext.getContext(request);
        if (context != null) {
            l.info("***Header was: " + (String) context.getAttribute("header"));
            context.putAttribute("header", "/WEB-INF/tiles/headerLoggedIn.jsp");
            l.info("***just reset header");
        } else {
            l.info("***context was NULL");
        }
    }
 
    //This method gets called when you specify a 'controllerUrl' attribute in tiles definition
    public ActionForward execute(ActionMapping mapping, ActionForm form,
        HttpServletRequest request, HttpServletResponse response) throws Exception {
        
        l.info("***DynamicTileController execute called");
        
        // Try to retrieve tile context
        ComponentContext context = ComponentContext.getContext(request);
        if (context == null) {
            throw new ServletException("Can't find Tile context for '"
                + this.getClass().getName()
                + "'. TilesAction subclasses must be called from a Tile");
        } else {
            l.info("***Header was: " + (String) context.getAttribute("header"));
            context.putAttribute("header", "/WEB-INF/tiles/headerLoggedIn.jsp");
            l.info("***just reset header");
        }
        
        return null;
    }
}

base.jsp

  
<%@ taglib uri="/tags/struts-tiles" prefix="tiles" %>
<%@ taglib uri="/tags/struts-html" prefix="html" %>
<%@ taglib uri="/tags/struts-logic" prefix="logic" %>
<%@ taglib uri="/tags/struts-bean" prefix="bean" %>
 
<%@ page import="java.util.Enumeration" %>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>Dynamic Tiles Test</title>
  </head>
 
  <body bgcolor="FFFFFF">
 
  <%//FOR TESTING/DEBUGGING ONLY - PRINTS ALL SESSION VARIABLES
      if (session != null) {
        out.print("<u><b>Session Variables:</b></u><br />");
        Enumeration e = session.getAttributeNames();
        while (e.hasMoreElements()) {
          String name = (String) e.nextElement();
          out.print(name + " = " + session.getAttribute(name) + "<br />");
        }
        out.print("<br />");
      }
  %>
 
    <logic:messagesPresent>
      <center>
        <bean:message key="errors.header"/>
          <ul>
            <html:messages id="error">
              <li><bean:write name="error"/></li>
            </html:messages>
          </ul><br />
      </center>
    </logic:messagesPresent>
    
    <tiles:get name="header" />
    <tiles:get name="body" />
    <tiles:get name="footer" />
 
  </body>
</html>

loginBody.jsp

  
<%@ taglib uri="/tags/struts-html" prefix="html" %>
  <center>
    <hr />
    Login Page Body
    <br />
 
    <html:link action="page2">Click here to be logged in</html:link>
    <br />
    <hr />
  </center>

headerLoggedIn.jsp

<table width="100%" bgcolor="red">
  <tr>
    <td><font color="blue">LOGGED IN!</font></td>
  </tr>
</table>

page2.jsp

  
<center>
  <h1>This is PAGE 2</h1>
</center>

[ August 17, 2004: Message edited by: Anthony Watson ]

[Leandro Melo]

Anthony,
didn`t test your code yet, but that`s what i was taking about.
It seems to be very nice.
The TilesAction class provides a nice api to get/put attributes.
Not too many people know about that, but it`s a nice feature.
The other link i sent in my second post also has some sample code for those interesteds.

Thanks and Regards,
ltcmelo