isBefore function
check if the string is a date that's before the specified date
If date
is not passed, it defaults to now.
Implementation
bool isBefore(String? str, [date]) {
if (date == null) {
date = DateTime.now();
} else if (isDate(date as String)) {
date = DateTime.parse(date);
} else {
return false;
}
DateTime str_date;
try {
str_date = DateTime.parse(str!);
} catch (e) {
return false;
}
return str_date.isBefore(date as DateTime);
}