Nested Promise and Formatting Example

FormattingExample.ts

class Formatting {
  private getCountriesQuery(skip: number, limit: number, order: string, searchName: string) {
    const Continentscountriescities_Country = Parse.Object.extend('Continentscountriescities_Country');
    const query = new Parse.Query(Continentscountriescities_Country);
    query.limit(limit); // limit to at most 10 results
    query.skip(skip); // skip the first 10 results
    const orders: string[] = order.split(',');
    orders.map(o => {
      if (o.startsWith('-')) {
        query.descending(o.replace('-', '')); // Sorts the results in descending order by the views field
      } else {
        query.ascending(o); // Sorts the results in ascending order by the likes field
      }
    });
    if (searchName) {
      query.skip(0);
      query.limit(100);
      query.startsWith('name', searchName); // name starts with "search field2"
    }
    return query;
  }

  public fetchCountriesFromApiParser(skip = 0, limit = 10, order = 'code', searchName: string) {
    return new Promise<ICountry[]>((resolve, reject) => {
      const query = this.getCountriesQuery(skip, limit, order, searchName);

      function transformCountry(country: any) {
        return country.get('languages')
          .query()
          .find()
          .then(async language => {
            // Do lang.get(string) return promises?
            return await Promise.all(language.map(lang => `${lang.get('name')} [${lang.get('code')}]`));
          })
          .then(async languages => {
            return { languages, timezone: await country.get('timezones').query().find() };
          })
          .then(({languages, timezone}) => {
            return new Country(
              undefined, 
              country.id, 
              country.get('name'), 
              country.get('code'), 
              country.get('native'), 
              country.get('phone'), 
              country.get('capital'),
              country.get('currency'),
              country.get('emoji'), 
              country.get('emojiU'), 
              country.get('geonameid'), 
              languages.toString(), 
              JSON.stringify(timezone.map(tz => tz.get('TimeZone'))),
              country.get('continent'), 
              country.get('createdAt'),
              country.get('updatedAt'), 
              false, 
              country.get('provinces'));
          });
      }
      query.find().then(results => {
        Promise.all(results.map(country => transformCountry(country)))
          .then(res => resolve(res));
      }, error => {
        reject(error);
      });
    });
  }
}