@Override
  public ActionForward render(
      ActionMapping actionMapping,
      ActionForm actionForm,
      PortletConfig portletConfig,
      RenderRequest renderRequest,
      RenderResponse renderResponse)
      throws Exception {

    try {
      long nodeId = ParamUtil.getLong(renderRequest, "nodeId");

      if (nodeId > 0) {
        ActionUtil.getNode(renderRequest);
      }
    } catch (Exception e) {
      if (e instanceof NoSuchNodeException || e instanceof PrincipalException) {

        SessionErrors.add(renderRequest, e.getClass());

        return actionMapping.findForward("portlet.wiki.error");
      } else {
        throw e;
      }
    }

    return actionMapping.findForward(getForward(renderRequest, "portlet.wiki.edit_node"));
  }
  @Override
  public String render(RenderRequest renderRequest, RenderResponse renderResponse)
      throws PortletException {

    try {
      WikiNode node = ActionUtil.getNode(renderRequest);

      renderRequest.setAttribute(WikiWebKeys.WIKI_NODE, node);

      WikiPage page = ActionUtil.getPage(renderRequest);

      renderRequest.setAttribute(WikiWebKeys.WIKI_PAGE, page);
    } catch (Exception e) {
      if (e instanceof NoSuchNodeException
          || e instanceof NoSuchPageException
          || e instanceof PrincipalException) {

        SessionErrors.add(renderRequest, e.getClass());

        return "/wiki/error.jsp";
      } else {
        throw new PortletException(e);
      }
    }

    return "/wiki/edit_page_attachment.jsp";
  }
  @Override
  public String render(RenderRequest renderRequest, RenderResponse renderResponse)
      throws PortletException {

    try {
      renderRequest.setAttribute(WikiWebKeys.WIKI_IMPORTER_TRACKER, _wikiImporterTracker);

      WikiNode node = ActionUtil.getNode(renderRequest);

      renderRequest.setAttribute(WikiWebKeys.WIKI_NODE, node);
    } catch (Exception e) {
      if (e instanceof NoSuchNodeException || e instanceof PrincipalException) {

        SessionErrors.add(renderRequest, e.getClass());

        return "/wiki/error.jsp";
      } else {
        throw new PortletException(e);
      }
    }

    return "/wiki_admin/import_pages.jsp";
  }