How to sort list of object by ISO8601

Question

I've got a list of object which after looping I'm trying to sort the final list by given ISO8601 format favouriteDateTime: 2022-12-16T10:46:55.551Z. There are mutiple sorting method but which one to use and how to sort it.

List<Movies> get Movies{
List<Movies> favMoviesList = <Movies>[];
for (final category in _appData.categories) {
  for (final series in category.series!) {
    final favMovies = series.movie!
        .where((movie) =>
            movie.stats != null && movie.stats!.isFavourite == true)
        .toList();

    if (favMovies.length > 0) {
     
    List<Movies> sorted = favMovies
       ..sort((a, b) => b.stats!.favoriteDateTime!
            .compareTo(a.stats!.favoriteDateTime!));
      favMoviesList.addAll(sorted);
    }}}

return favMoviesList;
}

Answer 1

Looks like you've already got a working implementation here. ISO8601 timestamps can just be sorted with string comparison - for two ISO strings a and b, a > b will always be true if time a is after time b, and the inverse is also true.

As far as the actual sorting method goes, you've got the right idea here with using sort(). Just make sure you only have one period -- favMovies.sort(), not favMovies..sort().

Also, List.sort() does not return the sorted list, it sorts the list in place. So your sorting code should be:

favMovies.sort((a, b) => 
  b.stats!.favoriteDateTime!.compareTo(a.stats!.favoriteDateTime!)
);
favMoviesList.addAll(favMovies);