constructor<T> static method

FhirDateTimeBase constructor<T>(dynamic inValue, [ DateTimePrecision? precision ])

Trying to consolidate dynamic constructors into a single factory, that has now turned into a static method, but functions the same way. The input can be a String, a dart DateTime, a FhirDateTimeBase, or an other.

Implementation

static FhirDateTimeBase constructor<T>(
  dynamic inValue, [
  DateTimePrecision? precision,
]) {
  String? input;
  String? exception;
  Map<String, int?>? dateTimeMap;
  bool regexpValid = true;

  if (inValue is String) {
    input = _cleanInput(inValue);
    final String replaced = input.replaceAll(
        T == FhirDateTime
            ? dateTimeExp
            : T == FhirInstant
                ? instantExp
                : dateExp,
        '');
    if (replaced.isNotEmpty &&
        (replaced != 'T' || (T == FhirDate && replaced == 'T')) &&
        replaced.trim().isNotEmpty) {
      regexpValid = false;
    }
  } else if (inValue is DateTime) {
    input = inValue.toIso8601String();
    if (inValue.isUtc) {
      input += 'Z';
    } else if (inValue.timeZoneOffset.inHours != 0) {
      input += timeZoneOffsetToString(inValue.timeZoneOffset.inHours);
    } else {
      precision ??= DateTimePrecision.yyyy_MM_dd_T_HH_mm_ss_SSS;
    }
  } else if (inValue is FhirDateTimeBase) {
    return constructor<T>(inValue.input, precision);
  } else {
    exception =
        "$T cannot be constructed from '$inValue' (unsupported type).";
  }

  String? output;
  if (input != null) {
    dateTimeMap = formatDateTimeString<T>(input);
  }
  if (dateTimeMap != null) {
    if (precision == null) {
      precision = precisionFromMap(dateTimeMap);
    } else {
      output = precision.dateTimeMapToString<T>(dateTimeMap);
    }
  }

  return _constructor<T>(
      dateTimeMap, precision, exception, output ?? inValue, regexpValid);
}