How to change the rendering for an object with "propertyNames" keys via custom widgets?

[eugeniumegherea]

Hello. So I have this challenge where I need to render custom component for the dynamic keys in an object. I know that we can easily define custom widget for array values via ui:widget, but how to do it for the keys?

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "bundles.recommendation",
  "type": "object",
  "description": "…",
  "propertyNames": {
    "pattern": "^[a-zA-Z0-9-]+$"
  },
  "additionalProperties": {
    "type": "object",
    "properties": {
      "fixed": {
        "type": "array",
        "items": {
          "type": "string"
        },
        "description": "Fixed bundle recommendations for this menu."
      },
      "random": {
        "type": "array",
        "items": {
          "type": "string"
        },
        "description": "Random bundle recommendations for this menu."
      }
    },
    "required": []
  }
}

and having this ui schema:

{
  "additionalProperties": {
    "fixed": {
      "items": {
        "ui:widget": "bundle-picker"
      }
    },
    "random": {
      "items": {
        "ui:widget": "bundle-picker"
      }
    }
  }
}

this is what I get as output

example correct object:

{
  "5980e379-186e-4180-aaf6-cbc724d9feac": {
    "random": [
      "f2d3b5ae-7f30-461f-8823-dd66a73d748d",
      "121a79f2-022a-4d78-86fd-cca78997ca6a",
      "2a24a318-e33a-4a8a-8594-f2187bb02811",
      "b73775f8-1dcb-46aa-96ff-1aa7cb684348",
      "75688058-55d9-4d72-aba3-8d95d04d05a9"
    ]
  }
}