You don’t need a fancy visual designer to build workflows. To be clear, Kaleo Designer may make you a faster workflow designer through its graphical interface. If you plan to build lots of workflow processes, a Digital Enterprise subscription gets you access to Kaleo Designer. But with a little copy and paste from existing workflows and a little handcrafted XML, you can build any workflow and attain workflow wizard-hood in the process. Follow this set of tutorials to learn what elements you can put into your definitions.
Existing Workflow Definitions
Only one workflow definition is installed by default: Single Approver. Several more, however, are embedded in the source code of your Liferay DXP installation. If you’re comfortable extracting the XML files from a JAR file embedded in an LPKG file, you’re welcome to follow the steps below to obtain the workflow definitions. To obtain the files more conveniently, download a ZIP file here.
To extract the definitions for yourself, navigate to
and open (using an archive manager)
Liferay CE Forms and Workflow.lpkg. Open
the JAR file named
In the JAR file, navigate to
and extract the four XML workflow definition files. These definitions provide good reference material for many of the workflow features and elements described in these articles. In fact, most of the XML snippets you see here are lifted directly from these definitions.
The XML structure of a workflow definition is defined in an XSD file:
Declare the schema at the top of the workflow definition file:
<?xml version="1.0"?> <workflow-definition xmlns="urn:liferay.com:liferay-workflow_7.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:liferay.com:liferay-workflow_7.0.0 http://www.liferay.com/dtd/liferay-workflow-definition_7_0_0.xsd">
To read 464 lines of beautifully formatted XML that defines how to write more XML (it’s practically poetic), check out the XSD here. Otherwise, move on to entering the definition’s metadata.
Give the definition a name, description, and version:
<name>Category Specific Approval</name> <description>A single approver can approve a workflow content.</description> <version>1</version>
All these tags are optional. If present the first time a definition is saved,
<name> tag serves as a unique identifier for the definition. If not
specified (or added sometime after the first save), a random unique name is
generated and used to identify the workflow.
Once the schema and metadata are in place, it’s time to turn up the funky beats and get into the flow (the workflow). Learn about workflow nodes in the next article.