Implementing Workflow Handlers

In this section you’ll learn to implement workflow handlers. Workflow handlers are fairly simple classes that interact with both the portal’s workflow classes and your service layer (by calling updateStatus on the appropriate entity).

Creating a Workflow Handler for Guestbook Entries

Create a new package in your docroot/WEB-INF/src folder and call it com.liferay.docs.guestbook.workflow. Create a new class in the package called EntryWorkflowHandler. Populate it with the following code:

public class EntryWorkflowHandler extends BaseWorkflowHandler {

    @Override
    public String getClassName() {
        
        return CLASS_NAME;
    }

    @Override
    public String getType(Locale locale) {
        return ResourceActionsUtil.getModelResource(locale, getClassName());
    }

    @Override
    public Object updateStatus(int status,
            Map<String, Serializable> workflowContext) throws PortalException,
            SystemException {

            long userId = GetterUtil.getLong(
                (String)workflowContext.get(WorkflowConstants.CONTEXT_USER_ID));
            long entryId = GetterUtil.getLong(
                (String)workflowContext.get(
                    WorkflowConstants.CONTEXT_ENTRY_CLASS_PK));

            ServiceContext serviceContext = (ServiceContext)workflowContext.get(
                "serviceContext");

            return EntryLocalServiceUtil.updateStatus(
                userId, entryId, status, serviceContext);

    }

    public static final String CLASS_NAME = Entry.class.getName();

}

Organize imports:

import java.io.Serializable;
import java.util.Locale;
import java.util.Map;

import com.liferay.docs.guestbook.model.Entry;
import com.liferay.docs.guestbook.service.EntryLocalServiceUtil;
import com.liferay.portal.kernel.exception.PortalException;
import com.liferay.portal.kernel.exception.SystemException;
import com.liferay.portal.kernel.language.LanguageUtil;
import com.liferay.portal.kernel.util.GetterUtil;
import com.liferay.portal.kernel.workflow.BaseWorkflowHandler;
import com.liferay.portal.kernel.workflow.WorkflowConstants;
import com.liferay.portal.service.ServiceContext;

Your workflow handler class extends the abstract class BaseWorkflowHandler, which implements the WorkflowHandler interface. The methods included in the workflow handler are methods with no implementation in BaseWorkflowHandler. The most important thing to note is that this class calls updateStatus from EntryLocalServiceUtil. You’ll add that method later.

Creating a Workflow Handler for Guestbooks

Each workflow enabled entity needs a WorkflowHandler. Create GuestbokWorkflowHandler in com.liferay.docs.guestbook.workflow. Populate it with the following code:

public class GuestbookWorkflowHandler  extends BaseWorkflowHandler {

    @Override
    public String getClassName() {

        return CLASS_NAME;
    }

    @Override
    public String getType(Locale locale) {
        return ResourceActionsUtil.getModelResource(locale, getClassName());
    }

    @Override
    public Object updateStatus(int status,
            Map<String, Serializable> workflowContext) throws PortalException,
            SystemException {

            long userId = GetterUtil.getLong(
                (String)workflowContext.get(WorkflowConstants.CONTEXT_USER_ID));
            long guestbookId = GetterUtil.getLong(
                (String)workflowContext.get(
                    WorkflowConstants.CONTEXT_ENTRY_CLASS_PK));
            
            ServiceContext serviceContext = (ServiceContext)workflowContext.get(
                "serviceContext");

            return GuestbookLocalServiceUtil.updateStatus(
                userId, guestbookId, status, serviceContext);

    }

    public static final String CLASS_NAME = Guestbook.class.getName();

}

Now the Guestbook App not only can update the database with the necessary information, but also can interact with Liferay’s workflow classes to make sure each entity is properly handled by the portal. The updateStatus method called in this class must be added to your local service implementation. You’ll do that in the next section of the Learning Path.

Registering the Guestbook Portlet’s Workflow Handlers

Now that you have new -WorkflowHandlers, you need to register them with Liferay. Add the following lines to docroot/WEB-INF/liferay-portlet.xml, underneath the <asset-renderer-factory> declaration:

	<workflow-handler>com.liferay.docs.guestbook.workflow.EntryWorkflowHandler</workflow-handler>
    <workflow-handler>com.liferay.docs.guestbook.workflow.GuestbookWorkflowHandler</workflow-handler>

Both the Guestbook App’s entities are now prepared to be handled by the portal’s workflow. To make this work, the service layer still needs some updating to set the initial workflow status, send the entity through the portal’s workflow (if any), and persist the status to the database after it’s returned from the workflow process.

« Approving Content with WorkflowEnabling Workflow at the Service Layer »