Optional zeebe:input and zeebe:output

[pinussilvestrus]

Closes #559

Script to try it out

npx @bpmn-io/sr bpmn-io/bpmn-js-properties-panel#559-optional-inputs-outputs -c "npm run start:cloud-templates"

[nikku]

I can confirm it works, I did not check the implementation.

[pinussilvestrus]

Please note, that optional is a normal property here, no constraint, since it has no real UI validation usage.

{
  "value": "input-1-source",
  "type": "String",
  "optional": true,
  "binding": {
    "type": "zeebe:input",
    "name": "input-1-target"
  }
}

[marstamm]

Trying to wrap my head around what's checked here. My assumption would be we always want to update when the property changes and when it is not optional.

I'm wondering if isOptional is needed here. shouldUpdate returns false when the value is empty and optional. For the second condition, isOptional should always be true when we reach it, or am I missing something?

[pinussilvestrus]

You are totally right, the second isOptional does not make sense here, also syntax-wise: If the property is optional (and has an empty value), the old input/output should be cleaned up (unless changed).

[marstamm]

Looks good to me!