Introduction to Workflow

Liferay’s workflow engine is named Kaleo. In Greek, Kaleo means “called ones,” which is appropriate for a workflow engine that calls users to participate in a review process designed for them. Kaleo workflow makes it possible to define any number of simple to complex business processes/workflows, deploy them, and manage them through a portal interface. The processes have knowledge of Users, Groups and Roles. You don’t have to write a single line of code to accomplish this: it can be defined in an XML document, or if you’re a Liferay Digital Experience Platform (DXP) customer, you have access to a nifty visual designer for workflows, called Kaleo Designer.

There are several steps to effective workflowing:

• Designing review processes in XML

• (DXP only) Designing review processes in Kaleo Designer

• Uploading workflow definitions

• Activating workflow for enabled assets

• Managing Workflow definitions

• Sending assets through review

After all that, you’ll be familiar with using Liferay’s Kaleo workflow to set up approval processes for any workflow-enabled content.

What’s New with Workflow

There are some noteworthy enhancements to the workflow functionality:

• Duplicate a workflow.

• Preview and restore a prior version.

• Save draft workflows and retain them in an unpublished state (this is a new feature for Liferay Portal CE workflow users).

• All Control Panel workflow functionality is unified under one entry, found at Control Panel → Configuration → Workflow.

• Create workflows (using a text editor for Liferay Portal CE users, and the Workflow Designer for Liferay DXP customers) at Control Panel → Configuration → Workflow. Just click the Add button.

Create your own workflows from scratch or leverage existing workflows.

Embedded Workflows

In addition to the Single Approver definition, there are some workflow definitions that ship with Liferay DXP but are not pre-installed, since they’re primarily included for test cases. They can be found in the Liferay source code in /modules/apps/portal-workflow/portal-workflow-kaleo-runtime-impl/src/main/resources/META-INF/definitions, or in your Liferay installation itself. Open your Liferay installation’s osgi/portal/com.liferay.portal.workflow.kaleo.runtime.impl.jar, and then find and open the com.liferay.workflow.kaleo.runtime.impl-[version].jar. The definitions are in the META-INF/definitions folder (see the diagrams here).