tryParse in DateFormat in dart flutter-CodePudding

Hi I want to tryParse multiple date formats. tryParse method is available in DateTime but not in DateFormat. I want to use DateFormat as I want to parse multiple format. If I use Parse method then I have to use a try catch block.

Currently I am parsing a single date format below. For parsing another date format I have to add it in the catch block.

try {
  print(DateFormat('MM/dd/yyyy').parse(line.text));
      scannedString = line.text;
} catch (e) {
  // parse another date format
}

I am searching for a more convenient way for parsing multiple date formats. Feel free to share your insights and I plan to share if I find any. Thanks for reading!

CodePudding user response：

If you want, you can easily add your own tryParse function or extension method that operates on a DateFormat:

extension DateFormatTryParse on DateFormat {
  DateTime? tryParse(String inputString, [bool utc = false]) {
    try {
      return parse(inputString, utc);
    } on FormatException {
      return null;
    }
  }
}

If you have a number of different formats that you'd like to try, you also could process them in a loop:

/// Attempts to parse a [String] to a [DateTime].
///
/// Attempts to parse [dateTimeString] using each [DateFormat] in [formats].
/// If none of them match, falls back to parsing [dateTimeString] with
/// [DateTime.tryParse].
///
/// Returns `null` if [dateTimeString] could not be parsed.
DateTime? tryParse(
  Iterable<DateFormat> formats,
  String dateTimeString, {
  bool utc = false,
}) {
  for (var format in formats) {
    try {
      return format.parse(dateTimeString, utc);
    } on FormatException {
      // Ignore.
    }
  }

  return DateTime.tryParse(dateTimeString);
}