parseTextString function

String parseTextString(String text, { String? locale, })

Expands Adaptive Cards {{DATE(...)}} and {{TIME(...)}} templates in display text.

Implementation

String parseTextString(String text, {String? locale}) {
  return text.replaceAllMapped(RegExp('{{.*}}'), (match) {
    final String? res = match.group(0);
    String? input = res?.substring(2, res.length - 2);
    input = input?.replaceAll(' ', '');

    final String? type = input?.substring(0, 4);
    if (type == 'DATE') {
      final String? dateFunction = input?.substring(5, input.length - 1);
      final List<String> items = dateFunction?.split(',') ?? [];
      if (items.length == 1) {
        items.add('COMPACT');
      }
      //if(items.length != 2) throw StateError('$dateFunction is not valid');
      // Wrong format
      if (items.length != 2) return res ?? '';

      final DateTime? dateTime = DateTime.tryParse(items[0]);

      DateFormat dateFormat;

      if (dateTime == null) return res ?? '';
      if (items[1] == 'COMPACT') {
        dateFormat = DateFormat.yMd(locale);
        return dateFormat.format(dateTime);
      } else if (items[1] == 'SHORT') {
        dateFormat = DateFormat('E, MMM d{n}, y', locale);
        return dateFormat
            .format(dateTime)
            .replaceFirst('{n}', getDayOfMonthSuffix(dateTime.day));
      } else if (items[1] == 'LONG') {
        dateFormat = DateFormat('EEEE, MMMM d{n}, y', locale);
        return dateFormat
            .format(dateTime)
            .replaceFirst('{n}', getDayOfMonthSuffix(dateTime.day));
      } else {
        // Wrong format
        return res ?? '';
      }
    } else if (type == 'TIME') {
      final String? time = input?.substring(5, input.length - 1);
      final DateTime? dateTime = DateTime.tryParse(time ?? '');
      if (dateTime == null) return res ?? '';

      final DateFormat dateFormat = DateFormat('jm', locale);

      return dateFormat.format(dateTime);
    } else {
      // Wrong format
      return res ?? '';
      //throw StateError('Function $type not found');
    }
  });
}