appendShape Issue

private modeling;
.
.
.
.
this.modeling = this.diagramModeler.get('modeling');
.
.
this.diagramElemRegistry.forEach(function(anElem){
      //identify and assign startEvent and Root
}
.
.
this.modeling.appendShape(startEventShape,{type: 'bpmn:Task'},{x: startEventShape.x+50,y: startEventShape.y+50},rt);

exception stack

unhandled error in event listener
EventBus._invokeListener @ bpmn-modeler.development.js?e75e:5233
EventBus._invokeListeners @ bpmn-modeler.development.js?e75e:5205
EventBus.fire @ bpmn-modeler.development.js?e75e:5167
CommandStack._fire @ bpmn-modeler.development.js?e75e:40151
eval @ bpmn-modeler.development.js?e75e:40215
CommandStack._atomicDo @ bpmn-modeler.development.js?e75e:40172
CommandStack._internalExecute @ bpmn-modeler.development.js?e75e:40203
CommandStack.execute @ bpmn-modeler.development.js?e75e:39952
Modeling.createShape @ bpmn-modeler.development.js?e75e:45134
AppendShapeHandler.preExecute @ bpmn-modeler.development.js?e75e:43034
CommandStack._internalExecute @ bpmn-modeler.development.js?e75e:40196
CommandStack.execute @ bpmn-modeler.development.js?e75e:39952
Modeling.appendShape @ bpmn-modeler.development.js?e75e:45188
onDeleteAll @ bpmn-view-component.ts?3b06:355
eval @ ViewDiagramComponent.html:1
handleEvent @ core.js?f18e:43992
callWithDebugContext @ core.js?f18e:45631
debugHandleEvent @ core.js?f18e:45246
dispatchEvent @ core.js?f18e:29803
eval @ core.js?f18e:42924
eval @ platform-browser.js?714a:2668
ZoneDelegate.invokeTask @ zone.js?d135:431
onInvokeTask @ core.js?f18e:39679
ZoneDelegate.invokeTask @ zone.js?d135:430
Zone.runTask @ zone.js?d135:198
ZoneTask.invokeTask @ zone.js?d135:513
invokeTask @ zone.js?d135:1671
globalZoneAwareCallback @ zone.js?d135:1697
bpmn-modeler.development.js?e75e:5234 TypeError: Cannot read property 'push' of undefined
    at BpmnUpdater.updateSemanticParent (bpmn-modeler.development.js?e75e:42664)
    at BpmnUpdater.updateParent (bpmn-modeler.development.js?e75e:42406)
    at updateParent (bpmn-modeler.development.js?e75e:42128)
    at eval (bpmn-modeler.development.js?e75e:42778)
    at invokeFunction (bpmn-modeler.development.js?e75e:5366)
    at EventBus._invokeListener (bpmn-modeler.development.js?e75e:5219)
    at EventBus._invokeListeners (bpmn-modeler.development.js?e75e:5205)
    at EventBus.fire (bpmn-modeler.development.js?e75e:5167)
    at CommandStack._fire (bpmn-modeler.development.js?e75e:40151)
    at eval (bpmn-modeler.development.js?e75e:40215)

Is this about custom rendering?

Yes. I’m trying to programmatically (Angular 8) add an existing shape (not a custom shape)

Appending a shape works like this:

const startEvent = elementRegistry.get("StartEvent_1");

const task = elementFactory.createShape({ type: "bpmn:Task" });

modeling.appendShape(startEvent, task, { x: 500, y: 500 });

It worked with the suggested code. thank you