Background

Some fields in the chart definition json are optional like subtitle. The subtitle field accepts localized string values like:

{
  "subtitle": {
    "de": "Bevölkerung im Jahr 2025",
    "en": "Population in 2025",
  }
}

If subtitle is an empty object, then there are validation errors but perhaps the chart validation could handle this more gracefully and treat the value as missing or empty.

In the ChartWizard project, I was seeing:

Parameter "subtitle" must be an object that maps valid language codes to single line strings no longer than 400 characters, without tabs or trailing spaces, e.g. { "en":"String in English", ... } when the chart definition json had "subtitle": {}

Proposed solution

In JCChartContent, add handling for optional localized fields, and consider normalizing so that when the chart definition has, "subtitle": {} then it can be omitted.