/* * public void Write<T>( * IEnumerable<T> values, * string fileName, * ExportFileDescription fileDescription) * { * using (StreamWriter sw = new StreamWriter( * fileName, * false, * fileDescription.TextEncoding)) * { * WriteData<T>(values, fileName, sw, fileDescription); * } * } * * * public void Write<T>( * IEnumerable<T> values, * TextWriter stream) * { * Write<T>(values, stream, new ExportFileDescription()); * } * * public void Write<T>( * IEnumerable<T> values, * string fileName) * { * Write<T>(values, fileName, new ExportFileDescription()); * } * * public void Write<T>( * IEnumerable<T> values, * TextWriter stream, * ExportFileDescription fileDescription) * { * WriteData<T>(values, null, stream, fileDescription); * } * */ private void WriteData <T>( IEnumerable <T> values, string fileName, TextWriter stream, ExportFileDescription fileDescription, Func <int, bool> myMethodName = null) { FieldMapper <T> fm = new FieldMapper <T>(fileDescription, fileName, true, Key); ExportStream cs = new ExportStream(null, stream, fileDescription); List <string> row = new List <string>(); // If first line has to carry the field names, write the field names now. if (fileDescription.FirstLineHasColumnNames) { fm.WriteNames(ref row); cs.WriteRow(row); } // ----- int i = 0; foreach (T obj in values) { i++; if (myMethodName != null) { myMethodName(i); } // Convert obj to row fm.WriteObject(obj, ref row); cs.WriteRow(row); } }
public IEnumerable <T> ReadData <T>( string fileName, StreamReader stream, ExportFileDescription fileDescription) where T : class, new() { // If T implements IDataRow, then we're reading raw data rows bool readingRawDataRows = typeof(IDataRow).IsAssignableFrom(typeof(T)); #if DEBUG List <T> ret = new List <T>(); #endif // The constructor for FieldMapper_Reading will throw an exception if there is something // wrong with type T. So invoke that constructor before you open the file, because if there // is an exception, the file will not be closed. // // If T implements IDataRow, there is no need for a FieldMapper, because in that case we're returning // raw data rows. FieldMapperReading <T> fm = null; if (!readingRawDataRows) { fm = new FieldMapperReading <T>(fileDescription, fileName, false, Key); } // ------- // Each time the IEnumerable<T> that is returned from this method is // accessed in a foreach, ReadData is called again (not the original Read overload!) // // So, open the file here, or rewind the stream. bool readingFile = !string.IsNullOrEmpty(fileName); if (readingFile) { stream = new StreamReader( fileName, fileDescription.TextEncoding, fileDescription.DetectEncodingFromByteOrderMarks); } else { // Rewind the stream if ((stream == null) || (!stream.BaseStream.CanSeek)) { // throw new BadStreamException(); throw new Exception(); } stream.BaseStream.Seek(0, SeekOrigin.Begin); } // ---------- ExportStream cs = new ExportStream(stream, null, fileDescription); // If we're reading raw data rows, instantiate a T so we return objects // of the type specified by the caller. // Otherwise, instantiate a DataRow, which also implements IDataRow. IDataRow row = null; if (readingRawDataRows) { row = new T() as IDataRow; } else { row = new DataRow(); } AggregatedException ae = new AggregatedException(typeof(T).ToString(), fileName, fileDescription.MaximumNbrExceptions); try { bool firstRow = true; while (cs.ReadRow(ref row)) { // Skip empty lines. // Important. If there is a newline at the end of the last data line, the code // thinks there is an empty line after that last data line. if ((row.Count == 1) && ((row[0].Value == null) || (string.IsNullOrEmpty(row[0].Value.Trim())))) { continue; } fm.CheckValid(row, ae); if (firstRow && fileDescription.FirstLineHasColumnNames) { if (!readingRawDataRows) { fm.ReadNames(row); } } else { T obj = default(T); try { if (readingRawDataRows) { obj = row as T; } else { obj = fm.ReadObject(row, ae); } } catch (FatalFormatException fex) { throw fex; } catch (AggregatedException ae2) { // Seeing that the AggregatedException was thrown, maximum number of exceptions // must have been reached, so rethrow. // Catch here, so you don't add an AggregatedException to an AggregatedException throw ae2; } catch (Exception ex) { // Store the exception in the AggregatedException ae. // That way, if a file has many errors leading to exceptions, // you get them all in one go, packaged in a single aggregated exception. ae.AddException(ex); } #if DEBUG ret.Add(obj); #else yield return(obj); #endif } firstRow = false; } } finally { if (readingFile) { stream.Close(); } // If any exceptions were raised while reading the data from the file, // they will have been stored in the AggregatedException ae. // In that case, time to throw ae. //ae.ThrowIfExceptionsStored(); } #if DEBUG return(ret); #endif }