Paneltab always remember user prev selection but not programmatic disclosed

Question

Hi,
Like the similar post Programmatic disclosure of showDetailItem under panelTabbed i would like the tab to be selected / disclosed based on the button the user click.
I have a paneltabbed component in a page called site which consists of 3 showdetailframe components ..let's call it as (tab1,tab2,tab3) . I have a button (go to site) in entirely different page called plot which should navigate to site page and open tab3 by default.
This works fine, for the first time. But let's say if user explictly clicked tab2 and then gone to plot page, click GoToSite button which navigates to Site page, but remembers the last selection user has made and selecting tab2 by default.
I have the following method in site page taskflow which is called always and evaluates the value which i set in the request scope on clicking GoToSite button.
     public void setCopyPlotTabOnSiteDetails()
          FacesContext context = FacesContext.getCurrentInstance();
          Map request = context.getCurrentInstance().getExternalContext().getRequestMap();
          Boolean copyPlotFlag = (Boolean)request.get("copyPlotReq");
          if (Boolean.TRUE.equals(copyPlotFlag) && panelTab != null)
               List<UIComponent> element = panelTab.getChildren();
               for (UIComponent child : element)
                    RichShowDetailItem sdi = (RichShowDetailItem)child;
                    if ("sdi2".equals(sdi.getId()))
                         sdi.setDisclosed(true);
                         _addAttributeChange(sdi, "disclosed", true);
                    AdfFacesContext.getCurrentInstance().addPartialTarget(sdi);
                    else
                    sdi.setDisclosed(false);
                    _addAttributeChange(sdi, "disclosed", false);     
                    AdfFacesContext.getCurrentInstance().addPartialTarget(sdi);
          AdfFacesContext.getCurrentInstance().addPartialTarget(siteDetails);
               AdfFacesContext.getCurrentInstance().addPartialTarget(panelTab);
After following the post Programmatic disclosure of showDetailItem under panelTabbed i added this method call addAttributeChange
     private static void _addAttributeChange(UIComponent uic, String attribName,
                                                       Object attribValue) {
          try
               FacesContext fc = FacesContext.getCurrentInstance();
               ChangeManager cm = RequestContext.getCurrentInstance().getChangeManager();
               ComponentChange cc = new AttributeComponentChange(attribName, attribValue);
               cm.addComponentChange(fc, uic, cc);
          catch (Exception e)
               // TODO: Add catch code
               e.printStackTrace();
But is giving NullPointerException on ChangeManager.
Even otherwise, i have removed the option Enable User Customizations from my View Project (checked in web.xml) and removed the ShowDetailFrame tag in Adf-config.xml. Put the disclosed property in DontPersist attribute of all those showdetail frame components. But nothing worked, i face the same issues...Can any one please help me?
Regards
Prabhu

Answer 1

Hi,
why do you work so cmplicated. Wouldn't it be simpler to point the disclosed property to a managed bean that then evaluates whether true/false should be returned instead of parsing the component tree? The managed bean would need to be in viewScope. Also note that a request parameter should be read by a pahse listener (f:view afterMethod listening to RESTORE_VIEW) because the ADF Faces page is not rendered in a single round trip but deferred by default which means that subsequent requests are issued. So the first request will be intercepted and then the value added to a bean or attribute in view scope for use by the tabs.
Another cause of error we frequently see is that personalization is enabled (with or witjout MDS) in which case the tab selection is saved as personalizes setting.
Also have a look at: http://docs.oracle.com/cd/E23943_01/apirefs.1111/e12419/tagdoc/af_showDetailItem.html
See: disclosedTransient and disclosed property and how to use them
Frank