public Onix5SchemaConverter(IEPubIdentifier identifier) { // if isbn bool bISBN = false; if (string.Compare(identifier.Scheme, "isbn", CultureInfo.InvariantCulture, CompareOptions.IgnoreCase) == 0) { string stripped = identifier.ID.Replace("-", string.Empty); if (stripped.Length == 13) { _type = OnixType.ISBN_13; bISBN = true; } else if (stripped.Length == 10) { _type = OnixType.ISBN_10; bISBN = true; } } else if (string.Compare(identifier.Scheme, "uri", CultureInfo.InvariantCulture, CompareOptions.IgnoreCase) == 0) { _type = OnixType.URN; _parsedId = string.Format("{0}", identifier.ID); } if (bISBN) { _parsedId = string.Format("urn:isbn:{0}", identifier.ID.Replace("-", string.Empty)); } if (_type == OnixType.Proprietary) { _parsedId = identifier.ID; } }