Creating Staged Models Manually

There are times when using Service Builder to generate your staged models is not practical. In these cases, you should create your staged models manually. Make sure to read the Adapting Your Business Logic to Build Staged Models section to determine if creating staged models manually is beneficial for your use case.

In this tutorial, you’ll explore how the Asset Link framework (a Liferay DXP framework used for relating assets) manually creates staged models. This framework is separate from Staging and is referenced solely as an example for how to leverage the ModelAdapterBuilder framework, which lets you adapt your model classes to staged models.

Asset links do not provide UUIDs by default; however, they still need to be tracked in the Staging and Export/Import frameworks. Therefore, they require staged models. Since they don’t provide a UUID, Service Builder cannot generate staged models for asset links. The Asset Link framework has to create staged models differently using the Model Adapter Builder. The naming convention for this interface typically follows the Staged[Entity] syntax. The Asset Link framework uses a generic entity called AssetLink.

Follow the steps below to leverage the Model Adapter Builder in your app.

1. Create a new interface that extends one of the staged model interfaces and your model specific interface. For example,

   public interface StagedAssetLink extends AssetLink, StagedModel {
   
   }
   

   This interface should define methods required for your model to qualify as a staged model. For asset links, methods for retrieving entry UUIDs (among others) are defined:

   public String getEntry1Uuid();
   
   public String getEntry2Uuid();
   

   These will be implemented by a new implementation class later.

2. Create an implementation class that implements your new Staged[Entity]. For example, the Asset Link framework does this:

   public class StagedAssetLinkImpl implements StagedAssetLink {
   
   }
   

   This class provides necessary logic for your entity model to be recognized as a staged model. Below is a subset of logic in the example StagedAssetLinkImpl class used to populate UUIDs for asset link entries:

   public StagedAssetLinkImpl(AssetLink assetLink) {
        _assetLink = assetLink;
   
       ...
   
        populateUuid();
   }
   
   @Override
   public String getEntry1Uuid() {
       if (Validator.isNotNull(_entry1Uuid)) {
           return _entry1Uuid;
       }
   
       populateEntry1Attributes();
   
       return _entry1Uuid;
   }
   
   @Override
   public String getEntry2Uuid() {
       if (Validator.isNotNull(_entry2Uuid)) {
           return _entry2Uuid;
       }
   
       populateEntry2Attributes();
   
       return _entry2Uuid;
   }
   
   protected void populateEntry1Attributes() {
   
       ...
   
       AssetEntry entry1 = AssetEntryLocalServiceUtil.fetchAssetEntry(
           _assetLink.getEntryId1());
   
       ...
   
       _entry1Uuid = entry1.getClassUuid();
   }
   
   protected void populateEntry2Attributes() {
   
       ...
   
       AssetEntry entry2 = AssetEntryLocalServiceUtil.fetchAssetEntry(
           _assetLink.getEntryId2());
   
       ...
   
       _entry2Uuid = entry2.getClassUuid();
   }
   
   protected void populateUuid() {
   
       ...
   
       String entry1Uuid = getEntry1Uuid();
       String entry2Uuid = getEntry2Uuid();
   
       ...
   
       _uuid = entry1Uuid + StringPool.POUND + entry2Uuid;
           }
   }
   
   private AssetLink _assetLink;
   private String _entry1Uuid;
   private String _entry2Uuid;
   private String _uuid;
   

   This logic retrieves asset link entries and populates UUIDs for them usable by the Staging and Export/Import frameworks. With the newly generated UUIDs, asset link model classes can be converted to staged models.

3. Create a Model Adapter Builder class and implement the ModelAdapterBuilder interface. You should define the entity type and your Staged Model Adapter class when implementing the interface:

   public class StagedAssetLinkModelAdapterBuilder
       implements ModelAdapterBuilder<AssetLink, StagedAssetLink> {
   
       @Override
       public StagedAssetLink build(AssetLink assetLink) {
           return new StagedAssetLinkImpl(assetLink);
       }
   
   }
   

   For the StagedAssetLinkModelAdapterBuilder, the entity type is AssetLink and the Staged Model Adapter is StagedAssetLink. Your app should follow a similar design. The Model Adapter Builder outputs a new instance of the Staged[Entity]Impl object.

4. Now you need to adapt your existing business logic to call the provided APIs. You can call the ModelAdapterUtil class to create an instance of your Staged Model Adapter. See how the Asset Link framework does this below:

   StagedAssetLink stagedAssetLink = ModelAdapterUtil.adapt(
       assetLink, AssetLink.class, StagedAssetLink.class);
   

   Once you’ve created Staged Model Data Handlers, you can begin exporting/importing your now Staging-compatible entities:

   StagedModelDataHandlerUtil.exportStagedModel(
       portletDataContext, stagedAssetLink);
   

   Visit the Understanding Data Handlers tutorial if you’re unfamiliar with how data handlers work.

Awesome! You’ve successfully adapted your business logic to build staged models!