3 Replies Latest reply on Jun 22, 2007 4:16 AM by Dennis

    Start a nested conversation

    Dennis Newbie

      Hello,

      am I thinking the right way?

      The problem is I try to start a nested conversation with an

      <a4j:commandLink action="{bean.action}" reRender="something"/>
      

      If I use this, their is no method invoked cause bean.action is annoted with

      @Begin(nested=true)
      public ......
      

      If I add the
      <s:conversationPropagation type="Begin" />


      I got the same effect...

      Or can I use s:link with an a4j:support flag? But I believe it's a quite uncool solution....

      Thanks for your help'!!

        • 1. Re: Start a nested conversation
          Gavin King Master

          I have no idea what you're trying to do here. Please give much more information.

          • 2. Re: Start a nested conversation
            Dennis Newbie

            The long explanation is something like this:

            Idea: Select and edit an entity bean, in a conversation

            I have a h:dataTable with buttons which have a seam like action method (el enhancement). The backing bean is annotated to start a conversation if the method is called. The first conversation is started and you get redirected to the an "edit" page.

            Here you can edit the attributes of the object. So I was able to implement the direct attributes. Now I tried to start a nested conversation to select the Master-Detail related entities.

            But this on an ajax (a4j + richfaces) enabled site.

            Do you need some code?

            • 3. Re: Start a nested conversation
              Dennis Newbie

              Here is the code:

              First seam bean
              These bean start the outer conversation, when a user gets selected (call select(object)).
              Now the user gets redirected to a page where he can see and edit the user.
              (The select method is called via an s:link)

              @Name("searchuser")
              @Conversational(ifNotBegunOutcome="start")
              @Scope(ScopeType.CONVERSATION)
              public class UserControl extends Selection implements Serializable {
              
               @In
               private PreLogin loginData;
              
               private boolean edit = false;
              
               public void edit(boolean edit) {
               this.edit = edit;
               }
              
               public User getSelected() {
               User selected = ((User)super.getSelected());
               if (selected != null) {
               selected.toString();
               }
               return selected;
               }
              
               @Begin
               public void add() {
               edit(true);
               setSelected(new User());
               }
              
               @Begin
               @End
               public void delete(User user) {
               if (user != null) {
               user.setStatus(StateEnum.DELETED);
               entityManager.merge(user);
               }
               }
              
               @Begin
               public void select(Object object) {
               super.select(object);
               }
              
               @End
               public void save() {
               entityManager.merge(getSelected());
               }
              
               @End
               public void cancel() {
               setSelected(null);
               }
              
               public List<User> getResult() {
               return super.getResult();
               }
              
               public String getQuery() {
               return Finder.searchUser(loginData.getUser().getClient().toString(), "surName", getSearch(), "surName");
               }
              
               public boolean isEdit() {
               return edit;
               }
              }
              
              public abstract class Selection {
              
               @In
               protected EntityManager entityManager;
              
               @Logger
               protected Log log;
              
               /**
               * The text of an input field filled by the user. This field is used to
               * filter the db query.
               */
               private String search = "";
              
               /**
               * The last selected object.
               */
               private Object selected;
              
               public String getSearch() {
               return search;
               }
              
               public void setSearch(String search) {
               this.search = search;
               }
              
               protected List getResult() {
               List query = entityManager.createQuery(getQuery()).getResultList();
               return query;
               }
              
               public Object getSelected() {
               return selected;
               }
              
               public void setSelected(Object selected) {
               this.selected = selected;
               }
              
               public void select(Object object) {
               setSelected(object);
               }
              
               public abstract String getQuery();
              }
              


              If the user clicks now on an link like:
               <a4j:commandLink value="Edit" action="#{subchannels.select(item)}" oncomplete="javascript:Richfaces.showModalPanel('subchannel',{width:450, top:200})" reRender="subchannelsSelectable, subchannelsEdit">
               <s:conversationId />
               <s:conversationPropagation type="Begin"/>
               </a4j:commandLink>
              

              or
               <a4j:commandLink value="Edit" action="#{subchannels.select(item)}" oncomplete="javascript:Richfaces.showModalPanel('subchannel',{width:450, top:200})" reRender="subchannelsSelectable, subchannelsEdit">
               <s:conversationId />
               <s:conversationPropagation type="nested"/>
               </a4j:commandLink>
              


              The nested conversation should start, the @Begin method is called, but I can't see the conversation anywhere....
              The second end up with a null pointer exception at java.lang.NullPointerException

              at org.jboss.seam.core.Manager.handleConversationPropagation(Manager.jav

              a:534)

              If I use the s:link I would really start to miss my ajax.... The problem is which one is the correct link solution (I believe)?