The source of the output is not editable when using element template

Describe the bug

When trying to create a service task template with outputs, the output doesn’t appear correctly. The target is editable instead of the source.

The element template:

{
  "$schema": "https://unpkg.com/@camunda/zeebe-element-templates-json-schema/resources/schema.json",
  "name": "Example",
  "id": "Example",
  "description": "The output is not correct",
  "appliesTo": [
    "bpmn:ServiceTask"
  ],
  "groups": [
    {
      "id": "inputs",
      "label": "Inputs"
    },
    {
      "id": "outputs",
      "label": "Outputs"
    }
  ],
  "properties": [
    {
      "value": "example-v1",
      "binding": {
        "type": "zeebe:taskDefinition:type"
      },
      "editable": false
    },
    {
      "description": "Output value",
      "group": "outputs",
      "label": "myTarget",
      "value": "myTarget",
      "type": "String",
      "binding": {
        "type": "zeebe:output",
        "source": "=\"mySource\""
      },
      "constraints": {
        "notEmpty": true
      }
    }
  ]
}

When the element template is linked: In the XML: <zeebe:output source="=&#34;mySource&#34;" target="myTarget" />

When the element template is unlinked: In the XML: <zeebe:output source="=&#34;mySource&#34;" target="myTarget" />

Steps to reproduce

1. Create a task using the element template
2. Check that the source is not editable
3. Unlink the element template using the camunda modeler
4. Check that without the element template, the source is editable

Expected behavior

The output source is editable when the element template is linked

Environment

Environent:

• OS: Ubuntu 20.04.3 LTS
• Camunda Modeler Version: 5.5.0
• Execution Platform: Camunda 8 Platform Self Managed
• Installed plug-ins: None

Additional context

Summarized here.

[tkuy]

Thank you for your advice @nikku This solution is good to me, it solves our problem! I’m closing the issue.

[nikku]

Moving to backlog.

The essential requested feature is to be able to not only assign an output variable, but rather incorporate the output into the process context (add to a list) using an expression.