buildSimpleLocationFieldOptions.js

/**
 * Combines indexed entries in the parallel arrays of a given location object.
 * Expects the same number of entries in each array.
 * 
 * @param data Object with parallel values in arrays.
 * @param separator String to use as a separator in the raw values.
 * @param display_separator String to use as a separator in the display values.
 * @param bottom_to_top Boolean to indicate if the values should be hierarchically displayed from bottom to top or top to bottom in the display values.
 * @returns Object with raw and display values in parallel arrays.
 * // The data is in the form:
 * {
 *   "country": ["USA", "USA", "USA", null, "USA", "France"],
 *     "state": ["CA", "CA", "NY", null, "TX", null],
 *       "city": ["Los Angeles", "San Francisco", "New York", "Abidjan", null, "Paris"]
 * }
 *
 * // The output should be:
 * {
 *   "display": ["USA", "CA, USA", "Los Angeles, CA, USA", "San Francisco, CA, USA", "NY, USA", "New York, NY, USA", "Abidjan", "TX, USA", "France", "Paris, France"],
 *     "raw": ["USA", "USA|CA", "USA|CA|Los Angeles", "USA|CA|San Francisco", "USA|NY", "USA|NY|New York", "||Abidjan", "USA|TX", "France", "France||Paris"]
 * }
 */
function buildSimpleLocationFieldOptions(data, separator = "|", display_separator = ', ', bottom_to_top = true) {
  let display = [];
  let raw = [];
  let visitedCountries = {};
  let visitedStates = {};
  for (let i = 0; i < data.country.length; i++) {
    const [country, state, city] = [data.country[i], (data.state ? data.state[i] : null), (data.city ? data.city[i] : null)];
    // add the country if it's not been seen before
    if (country && !(country in visitedCountries)) {
      display.push(country);
      raw.push(country);
      visitedCountries[country] = 1;
    }
    // add the state if it's not been seen before
    let stateKey = (country || '') + separator + state;
    if (state && !(stateKey in visitedStates)) {
      if (bottom_to_top)
        display.push(country ? (state + display_separator + country) : state);
      else
        display.push(country ? (country + display_separator + state) : state);
      raw.push(stateKey);
      visitedStates[stateKey] = 1;
    }
    // all 3 fields at the same time
    if (country && state && city) {
      if (bottom_to_top)
        display.push(city + display_separator + state + display_separator + country);
      else
        display.push(country + display_separator + state + display_separator + city);
      raw.push(country + separator + state + separator + city);
    }
    // 2 fields at a time
    else if (country && state) {
      // case covered above
    } else if (state && city) {
      if (bottom_to_top)
        display.push(state + display_separator + country);
      else
        display.push(country + display_separator + state);
      raw.push(country + separator + state);
    } else if (country && city) {
      if (bottom_to_top)
        display.push(city + display_separator + country);
      else
        display.push(country + display_separator + city);
      raw.push(country + separator + separator + city);
    }
    // individual fields
    else if (country) {
      // already covered above
    } else if (state) {
      // also covered above
    } else if (city) {
      display.push(city);
      raw.push(separator + separator + city);
    }

  }
  return { "display": display, "raw": raw };
}