core

Diagram Converter Core

This is the core module of the diagram converter, containing the BpmnConverter plus its factory, the BpmnConverterFactory.

How does it work?

Works in 2 phases:

• exploring the BPMN XML
  • this is done in a visitor pattern, the interface to use is DomElementVisitor
  • each element gets visited
  • convertibles are created for each process element
  • they can be decorated with aspects for the conversion
• the conversion is executed
  • decorated convertibles are processed
  • the registered aspects are adjusted in the BPMN XML
  • this is done in another visitor pattern, the interface to use is Conversion
  • the diagram becomes a Camunda 8 diagram

How can I use it?

You can bootstrap the BpmnConverter in an easy way:

BpmnConverter converter = BpmnConverterFactory.getInstance().get();

This will return a converter that is bootstrapped using SPI for DomElementVisitor, Conversion and NotificationService.

If you want to build a custom converter, you can add to the SPI resources.

If this is not sufficient, you can bootstrap the converter in a custom way:

import java.util.ArrayList;
import java.util.List;

List<DomElementVisitor> visitors = loadDomElementVisitors();
List<Conversion> conversions = loadConversions();
NotificationService notificationService = laodNotificationService();

BpmnConverter converter = new BpmnConverter(visitors, conversions, notificationService);

Next, you need ConverterProperties. They control the way the converter will handle several aspects of the conversion.

You can bootstrap the properties in an easy way:

ConverterProperties properties = ConverterPropertiesFactory.getInstance().get();

You can also customize the used converter properties:

DefaultConverterProperties defaultConverterProperties = new DefaultConverterProperties();
// I want to migrate to an older platform version
defaultConverterProperties.setPlatformVersion("8.5");

ConverterProperties properties = ConverterPropertiesFactory
        .getInstance()
        .merge(defaultConverterProperties);

Now, you are able to convert process models or just receive a check result:

BpmnConverter converter = BpmnConverterFactory
        .getInstance()
        .get();
// this comes from the camunda 7 bpmn model package
BpmnModelInstance modelInstance = loadModel();
ConverterProperties properties = ConverterPropertiesFactory.getInstance().get();

// the results will be in the provided modelInstance
converter.convert(modelInstance, properties);

// the results are returned, the model instance is also modified

BpmnDiagramCheckResult result = converter.check(modelInstance, properties);

How can I extend it?

Beside the way of using custom bootstrapping mechanisms, the easiest way to extend is by using the capabilities of the underlying SPI.

You can find an example in the /example section of the root project.