[jboss-user] [JBoss Seam] - @DataModelSelection behavior : bug or feature ?

[ve_rao]

When does a variable annotated as @DataModelSelection get injected? Is it only when a row in the <h:dataTable> is selected? Or does it get initialized whenever there is a postback, even from a control outside the <h:dataTable>?

I am observing that in addition to the first case above, the second is also true. Even when an action listener is invoked in response to a link outside the <h:dataTable> element, the @DataModelSelection variable is getting initialized to the first element of the @DataModel.

Is my observation correct? Is that the expected behavior? That is causing unexpected behavior in my code. I am attaching my sources below to better illustrate.

Thanks,

-- venkat


<h:form>
  | 
  |     <s:link value="Up one level"
  |             rendered="#{folderNavigator.curFolder != null}"
  |             action="#{folderNavigator.upOneLevel}" />
  | 
  |     <h:dataTable var="folder" value="#{folderList}" >
  |         <h:column>
  |             <s:link value="#{folder.folderName}"
  |                     action="#{folderNavigator.selectFolder}" />
  |         </h:column> 
  |     </h:dataTable>
  | 
  | </h:form>
In the listing above, "folderList" is a @DataModel, declared and used in the folderNavigator stateful session bean, which is given below:
@Stateful
  | @Scope(SESSION)
  | @Name("folderNavigator")
  | public class FolderNavigatorAction implements FolderNavigator, Serializable
  | {
  |     @DataModel
  |     private List<Folder> folderList;
  | 
  |     @DataModelSelection
  |     private Folder curFolder;
  | 
  |     @Factory("folderList")
  |     public void retrieveFolderList() {
  | 
  |         if (curFolder == null) {
  |             folderList = rootFolderList; // Initialized in constructor
  |         }
  |         else {
  |             folderList = curFolder.getChildFolders();
  |         }
  |     }
  | 
  |     public void selectFolder() {
  |         retrieveFolderList();
  |     }
  | 
  |     public void upOneLevel() {
  |         curFolder = curFolder.getParent();
  |         retrieveFolderList();
  |     }
  | }
When the upOneLevel() method is called, curFolder is automatically injected with the first element of folderList, even though it was not invoked in response to a data model selection.


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