"Custom" start event

Developers Modeler
1

Hi, I’m trying to create somewhat of a custom start event - it’s not really custom, it’s just going to be a start event with some specific extensionElements, and in my example case it’s called Event Registry Event.
I added the type name to my descriptor object:

{
      name: 'EventRegistryEvent',
      extends: ['bpmn:StartEvent'],
      properties: [
        {
          name: 'testProp',
          isAttr: true,
          type: 'String',
        },
        {
          name: 'textBody',
          isBody: true,
          type: 'String',
        },
      ],
    }

I’ve also added the menu entry to my custom MenuProvider:

getPopupMenuEntries(element) {
    return function (entries) {
      if (isAny(element, ['bpmn:StartEvent'])) {
        entries['replace-with-event-registry-event'] = {
          actionName: 'replace-with-event-registry-event',
          className: 'bpmn-icon-start-event-message',
          label: 'Event Registry Event',
          target: {
            type: 'bpmn:StartEvent',
            eventDefinitionType: 'myNameSpace:EventRegistryEvent',
          },
        };
      }
      return entries;
    };
  }

I do not understand the next step though, clicking on the menu entry obviously does nothing as I have no action defined, and I really am confused how would I attach an action to that menu entry and what is that action supposed to do? I would also like to attach a custom icon to both the menu entry and to the node being rendered afterwards…

image