How about a simple extension method for DateTime
. Run-time is probably not great, since we're iterating the string multiple times and iterating over each %
format option. Could probably walk through once and replace %
greedily.
extension DateTimeFormat on DateTime {
String format(String formatString) {
var hourString = hour.toString();
var dayString = day.toString();
var monthString = month.toString();
var minuteString = minute.toString();
var secondString = second.toString();
var yearString = year.toString();
var map = {
'%H': hourString.padLeft(3 - hourString.length, '0'),
'%d': dayString.padLeft(3 - dayString.length, '0'),
'%m': monthString.padLeft(3 - monthString.length, '0'),
'%M': minuteString.padLeft(3 - minuteString.length, '0'),
'%S': secondString.padLeft(3 - secondString.length, '0'),
'%Y': yearString.padLeft(5 - yearString.length, '0'),
};
return map.entries.fold(formatString, (acc, entry) => acc.replaceAll(entry.key, entry.value));
}
}
Usage:
print(DateTime(2021, 10, 16, 4, 4, 4, 4, 4).format('%Y-%m-%d-%H-%M-%S'));
// '2021-10-16-04-04-04'
Feel free to suggest changes.