/*
* 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
}
