@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.