Creating Staged Model Data Handlers

In this tutorial, you’ll create the BookmarksStagedModelDataHandler class used for the Bookmarks application. The Bookmarks application has two staged models: entries and folders. Creating data handlers for these two entities is similar, so you’ll examine how this is done for Bookmark entries. This tutorial assumes you’ve already created staged models.

1. Create a new package in your existing Service Builder project for your data handler classes. For instance, the Bookmarks application’s data handler classes reside in the bookmarks-service module’s com.liferay.bookmarks.internal.exportimport.data.handler package.

2. Create a -StagedModelDataHandler class in the -exportimport.data.handler package. The staged model data handler class should extend the BaseStagedModelDataHandler class and the entity type should be specified as its parameter. You can see how this was done for the BookmarksEntryStagedModelDataHandler class below:

   public class BookmarksEntryStagedModelDataHandler
       extends BaseStagedModelDataHandler<BookmarksEntry> {
   

3. Create an @Component annotation section above the class declaration.

   @Component(immediate = true, service = StagedModelDataHandler.class)
   

4. Create a getter and setter method for the local service of the staged model for which you want to provide a data handler:

   @Override
   protected BookmarksEntryLocalService getBookmarksEntryLocalService() {
       return _bookmarksEntryLocalService;
   }
   
   @Reference(unbind = "-")
   protected void setBookmarksEntryLocalService(
       BookmarksEntryLocalService bookmarksEntryLocalService) {
   
       _bookmarksEntryLocalService = bookmarksEntryLocalService;
   }
   
   private BookmarksEntryLocalService _bookmarksEntryLocalService;
   

   These methods are used to link this data handler with the staged model for bookmark entries.

   Important: Liferay DXP’s official Bookmarks app does not use local services in its staged model data handlers; instead, it uses the StagedModelRepository framework. This is a new framework, but is a viable option when setting up your staged model data handlers. For more information on this, see the Providing Entity-Specific Local Services for Staging tutorial section. Since local services are more widely used in custom apps, this tutorial covers those instead.

5. Provide the class names of the models the data handler tracks. You can do this by overriding the StagedModelDataHandler’s getClassnames() method:

   public static final String[] CLASS_NAMES = {BookmarksEntry.class.getName()};
   
   @Override
   public String[] getClassNames() {
       return CLASS_NAMES;
   }
   

6. Add a method that retrieves the staged model’s display name:

   @Override
   public String getDisplayName(BookmarksEntry entry) {
       return entry.getName();
   }
   

   The display name is presented with the progress bar during the export/import process.

   

   Figure 1: Your staged model data handler provides the display name in the Export/Import UI.

7. Add methods that import and export your staged model and its references.

   @Override
   protected void doExportStagedModel(
           PortletDataContext portletDataContext, BookmarksEntry entry)
       throws Exception {
   
       if (entry.getFolderId() !=
               BookmarksFolderConstants.DEFAULT_PARENT_FOLDER_ID) {
   
           StagedModelDataHandlerUtil.exportReferenceStagedModel(
               portletDataContext, entry, entry.getFolder(),
               PortletDataContext.REFERENCE_TYPE_PARENT);
       }
   
       Element entryElement = portletDataContext.getExportDataElement(entry);
   
       portletDataContext.addClassedModel(
           entryElement, ExportImportPathUtil.getModelPath(entry), entry);
   }
   
   @Override
   protected void doImportStagedModel(
           PortletDataContext portletDataContext, BookmarksEntry entry)
       throws Exception {
   
       Map<Long, Long> folderIds =
           (Map<Long, Long>)portletDataContext.getNewPrimaryKeysMap(
               BookmarksFolder.class);
   
       long folderId = MapUtil.getLong(
           folderIds, entry.getFolderId(), entry.getFolderId());
   
       ServiceContext serviceContext =
           portletDataContext.createServiceContext(entry);
   
       BookmarksEntry importedEntry = null;
   
       if (portletDataContext.isDataStrategyMirror()) {
   
           BookmarksEntry existingEntry =
               _bookmarksEntryLocalService. fetchBookmarksEntryByUuidAndGroupId(
                   entry.getUuid(), portletDataContext.getScopeGroupId());
   
           if (existingEntry == null) {
   
               serviceContext.setUuid(entry.getUuid());
               importedEntry = _bookmarksEntryLocalService.addEntry(					
                 userId, portletDataContext.getScopeGroupId(), folderId, entry.getName(), entry.getUrl(), entry.getDescription(), serviceContext);
           }
           else {
               importedEntry = _bookmarksEntryLocalService.updateEntry(
                   userId, existingEntry.getEntryId(), portletDataContext.getScopeGroupId(), folderId, entry.getName(), entry.getUrl(), entry.getDescription(),	serviceContext);
           }
       }
       else {
           importedEntry = _bookmarksEntryLocalService.addEntry(userId, portletDataContext.getScopeGroupId(), folderId,entry.getName(), entry.getUrl(), entry.getDescription(),	serviceContext);
       }
   
       portletDataContext.importClassedModel(entry, importedEntry);
   }
   

8. Add the doImportMissingReference method to your class:

   @Override
   protected void doImportMissingReference(
           PortletDataContext portletDataContext, String uuid, long groupId,
           long entryId)
       throws Exception {
   
       BookmarksEntry existingEntry = fetchMissingReference(uuid, groupId);
   
       if (existingEntry == null) {
           return;
       }
   
       Map<Long, Long> entryIds =
           (Map<Long, Long>)portletDataContext.getNewPrimaryKeysMap(
               BookmarksEntry.class);
   
       entryIds.put(entryId, existingEntry.getEntryId());
   }
   

Fantastic! You’ve created a data handler for your staged model. The Export/Import framework can now track your entity’s behavior and data. Be sure to also implement a portlet data handler to manage portlet specific data. See the Creating Portlet Data Handlers article to do this for the Bookmarks app.