fromJson method
Implementation
@override
DateTime fromJson(Object timestamp) {
if (timestamp is Timestamp) {
return timestamp.toDate();
} else if (timestamp is Map) {
Map<Object?, Object?> timestampMap = timestamp;
int seconds = timestampMap['_seconds'] as int;
int nanoseconds = timestampMap['_nanoseconds'] as int;
return DateTime.fromMicrosecondsSinceEpoch(seconds * 1000000 + nanoseconds ~/ 1000);
}
return DateTime.fromMillisecondsSinceEpoch(0);
}