{
  "title": "Custom Input",
  "type": "custom",
  "attribute": {
    "optional": {
      "style": "string inline stylesheet",
      "help": "string help-block",
      "placeholder": "string placeholder",
      "readonly": "boolean",
      "disabled": "boolean"
    },
    "required": {
      "html": "string html"
    }
  }
}