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Removing an element template from root element creates error

See original GitHub issue

Describe the Bug

When removing (not unlinking) an element template from a diagram root element (process or collaboration), an error occurs:

diagram_1.bpmn] Cannot read property 'children' of undefined
    at BpmnOrderingProvider.getOrdering (webpack-internal:///./node_modules/bpmn-js/lib/features/ordering/BpmnOrderingProvider.js:148:34)
    at eval (webpack-internal:///./node_modules/diagram-js/lib/features/ordering/OrderingProvider.js:53:25)
    at invokeFunction (webpack-internal:///./node_modules/diagram-js/lib/core/EventBus.js:517:13)
    at EventBus._invokeListener (webpack-internal:///./node_modules/diagram-js/lib/core/EventBus.js:368:19)
    at EventBus._invokeListeners (webpack-internal:///./node_modules/diagram-js/lib/core/EventBus.js:349:24)
    at EventBus.fire (webpack-internal:///./node_modules/diagram-js/lib/core/EventBus.js:310:24)
    at CommandStack._fire (webpack-internal:///./node_modules/diagram-js/lib/command/CommandStack.js:356:29)
    at CommandStack._internalExecute (webpack-internal:///./node_modules/diagram-js/lib/command/CommandStack.js:398:10)
    at CommandStack.execute (webpack-internal:///./node_modules/diagram-js/lib/command/CommandStack.js:153:8)
    at Modeling.createShape (webpack-internal:///./node_modules/diagram-js/lib/features/modeling/Modeling.js:310:22) [ error ]

Steps to Reproduce

Set up some template for bpmn:Process:

[
  {
    "name": "KPI Template",
    "id": "kpi",
    "appliesTo": [
      "bpmn:Collaboration","bpmn:Process","bpmn:Task","bpmn:IntermediateCatchEvent"
    ],
    "properties": [
      {
        "label": "KPI Unit",
        "type": "Dropdown",
        "value": "ms",
        "choices": [
          {
            "name": "Milliseconds", "value": "ms"
          },
          {
            "name": "Seconds", "value": "s"
          },
          {
            "name": "Minutes", "value": "m"
          },
          {
            "name": "Hours", "value": "h"
          }
        ],
        "editable": true,
        "binding": {
          "type": "camunda:property",
          "name": "kpiunit"
        }
      },
      {
        "label": "KPI Threshold",
        "type": "String",
        "value": "",
        "editable": true,
        "binding": {
          "type": "camunda:property",
          "name": "kpi"
        }
      }
    ]
  }
]

Apply element template to bpmn:Process
Remove the element template again (by clicking on Remove)

Expected Behavior

Removal of element template from Process creates no error / diagram is still valid.

Environment

OS: Arch Linux
Camunda Modeler Version: 4.6.0 master branch on 2.March 2021
Note: this fix is a precondition so to be able to reproduce this error: https://github.com/camunda/camunda-modeler/issues/2125

Issue Analytics

State:
Created 3 years ago
Comments:10 (10 by maintainers)

Top GitHub Comments

2reactions

philippfrommecommented, Mar 4, 2021

As an alternative to this bug fix we could also keep applying any templates on root elements disabled, for example.

I’d disable templates for root elements for now. Supporting them e2e including removal is not trivial and exceeds the initial scope of fixing a bug.

1reaction

pinussilvestruscommented, Mar 4, 2021

Nice Investigations @MaxTru 👏

I’d second @philippfromme @nikku 's opinion, if it’s too much hustle to support it, let’s not do it now. Your findings are a good starting point when we tackle it in the future.

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