3 Replies Latest reply on Aug 10, 2006 4:43 AM by hdslkf hklsdg

    DataModel not made available as a context variable

    zzzz8 Newbie

      Hi,

      I'm a newbie with Seam, but I've been having trouble with the DataModel annotation. I'm not sure if it's a configuration problem, but I've used the messages example in JBoss Seam 1.0.1 GA as a baseline for my configuration (took many of the configuration values and jars from there). I'm trying to upgrade a web app that currently runs on MyFaces 1.1.2, Tomahawk 1.1.2, and Tomcat 5.5.15. I'm also using Tiles - in particular, with Tiles Support from Tomahawk.

      I haven't done anything fancy yet - I've just tried to modify a simple existing page. Here's a snippet of code which I'm having problems with:

      @Stateful
      @Scope(ScopeType.SESSION)
      @Name("statusData")
      public class StatusBean implements StatusLocal {
       @In
       private Context sessionContext;
      
       @DataModel
       private List status;
      
       @Factory("status")
       private void retrieveStatus() {
       // Bus. logic code - sets status...
       }
      
       @Remove @Destroy
       public void destroy() {
      
       }
      }


      The interface only lists the destroy method...

      @Local
      public interface StatusLocal {
       public void destroy();
      }


      My JSP code attempts to get the DataModel from here...

      <h:dataTable value="#{status}" var="varStatus"...


      However, I get errors stating that it cannot evaluate the expression:
      ServletException ... .... Cannot get value for expression: #{status}


      When I debug in Eclipse, I notice that the StatusBean class is never even instantiated. Normally, one would think that there is a configuration problem. However, if I change the bean code to:

      @Stateful
      @Scope(ScopeType.SESSION)
      @Name("statusData")
      public class StatusBean implements StatusLocal {
       @In
       private Context sessionContext;
      
       private List myStatus = new ArrayList();
      
       public List getMyStatus() {
       return myStatus;
       }
      
       @Remove @Destroy
       public void destroy() {
      
       }
      }


      and for the interface code is:

      @Local
      public interface StatusLocal {
       public List getMyStatus();
       public void destroy();
      }


      and the JSP is:

      <h:dataTable value="#{statusData.myStatus}" var="varStatus"...


      It works! When I debug from inside Eclipse, I see that the bean is instantiated and the getter is called. I also see that the sessionContext context variable is injected correctly. These two things lead me to believe that my configuration is somewhat correct. I haven't tried any of the other annotations and features of Seam, so I hope things aren't broken there either?

      What am I doing wrong here? I would really appreciate any assistance, as I'm pretty much stuck...

      BTW, the messages example works within Tomcat 5.5.15 and if I replace the MyFaces 1.1.3 libs with MyFaces 1.1.2 libs within the messages example, it still works...