Currently, the output of the checkbox dialogue is useless when trying to parse with any JSON parser as you can't loop over the array of strings with something such as JQ as it's not valid json. Checkbox dialog now returns a values array with objects containing the index and value of the selected item. The index is useful for keeping track of values.

{ "code": -1,
  "text": "[test1, test2]",
  "values": [
    {
      "index": 0,
      "text": "test1"
    },
    {
      "index": 1,
      "text": "test2"
    }
  ]
}

For other dialogs which only return a single value but you are able to choose from a list I added an index to the result.

{ "code": 0,
  "text": "test2",
  "index": 1
}