parseFieldData = (tiddler, field = 'text', data) => {

  const tObj = getTiddler(tiddler);

  if (!tObj) {
    return data;
  }

  return basicUtils.parseJSON(tObj.fields[field], data);

}
Parse json from field or return default value on error.

@param {Tiddler} tiddler - The tiddler containing the json.
@param {string} field - The field with the json data.
@param {Object} [data] - An optional default value.
@return {*} Either the parsed data or the default data.