/// ///////////////////////////////////////////////////////////////////////
/// ReadData
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="fileName">
/// Name of the file associated with the stream.
///
/// If this is not null, a file is opened with this name.
/// If this is null, the method attempts to read from the passed in stream.
/// </param>
/// <param name="stream">
/// All data is read from this stream, unless fileName is not null.
///
/// This is a StreamReader rather then a TextReader,
/// because we need to be able to seek back to the start of the
/// stream, and you can't do that with a TextReader (or StringReader).
/// </param>
/// <param name="fileDescription"></param>
/// <returns></returns>
private IEnumerable <T> ReadData <T>(
string fileName,
StreamReader stream,
CsvFileDescription fileDescription) where T : class, new()
{
// If T implements IDataRow, then we're reading raw data rows
bool readingRawDataRows = typeof(IDataRow).GetTypeInfo().IsAssignableFrom(typeof(T).GetTypeInfo());
// 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.
FieldMapper_Reading <T> fm = null;
if (!readingRawDataRows)
{
fm = new FieldMapper_Reading <T>(fileDescription, fileName, false);
}
// -------
// 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(
File.Open(fileName, FileMode.Open),
fileDescription.TextEncoding,
fileDescription.DetectEncodingFromByteOrderMarks);
}
else
{
// Rewind the stream
if ((stream == null) || (!stream.BaseStream.CanSeek))
{
throw new BadStreamException();
}
stream.BaseStream.Seek(0, SeekOrigin.Begin);
}
// ----------
CsvStream cs = new CsvStream(stream, null, fileDescription.SeparatorChar, fileDescription.IgnoreTrailingSeparatorChar);
// 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
{
List <int> charLengths = null;
if (!readingRawDataRows)
{
charLengths = fm.GetCharLengths();
}
bool firstRow = true;
while (cs.ReadRow(row, charLengths))
{
// 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;
}
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 (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 e)
{
// 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(e);
}
yield return(obj);
}
firstRow = false;
}
}
finally
{
if (readingFile)
{
stream.Dispose();
}
// 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();
}
}
/// ///////////////////////////////////////////////////////////////////////
/// ReadObject
///
/// <summary>
/// Creates an object of type T from the data in row and returns that object.
///
/// </summary>
/// <param name="row"></param>
/// <param name="firstRow"></param>
/// <returns></returns>
public T ReadObject(IDataRow row, AggregatedException ae)
{
//If there are more columns than the required
if (row.Count > m_IndexToInfo.Length)
{
//Are we ignoring unknown columns?
if (!m_fileDescription.IgnoreUnknownColumns)
{
// Too many fields
throw new TooManyDataFieldsException(typeof(T).ToString(), row[0].LineNbr, m_fileName);
}
}
// -----
T obj = new T();
//If we will be using the mappings, we just iterate through all the cells in this row
int maxRowCount = _mappingIndexes.Count > 0 ? row.Count : Math.Min(row.Count, m_IndexToInfo.Length);
for (int i = 0; i < maxRowCount; i++)
{
TypeFieldInfo tfi;
//If there is some index mapping generated and the IgnoreUnknownColums is `true`
if (m_fileDescription.IgnoreUnknownColumns && _mappingIndexes.Count > 0)
{
if (!_mappingIndexes.ContainsKey(i))
{
continue;
}
tfi = m_IndexToInfo[_mappingIndexes[i]];
}
else
{
tfi = m_IndexToInfo[i];
}
if (m_fileDescription.EnforceCsvColumnAttribute &&
(!tfi.hasColumnAttribute))
{
// enforcing column attr, but this field/prop has no column attr.
// So there are too many fields in this record.
throw new TooManyNonCsvColumnDataFieldsException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
// -----
if ((!m_fileDescription.FirstLineHasColumnNames) &&
(tfi.index == CsvColumnAttribute.mc_DefaultFieldIndex))
{
// First line in the file does not have field names, so we're
// depending on the FieldIndex of each field in the type
// to ensure each value is placed in the correct field.
// However, now hit a field where there is no FieldIndex.
throw new MissingFieldIndexException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
// -----
if (m_fileDescription.UseFieldIndexForReadingData && (!m_fileDescription.FirstLineHasColumnNames) &&
(tfi.index > row.Count))
{
// First line in the file does not have field names, so we're
// depending on the FieldIndex of each field in the type
// to ensure each value is placed in the correct field.
// However, now hit a field where the FieldIndex is bigger
// than the total number of items in a row generated by the separatorChar
throw new WrongFieldIndexException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
int index = m_fileDescription.UseFieldIndexForReadingData ? tfi.index - 1 : i;
// value to put in the object
string value = row[index].Value;
if (value == null)
{
if (!tfi.canBeNull)
{
ae.AddException(
new MissingRequiredFieldException(
typeof(T).ToString(),
tfi.name,
row[i].LineNbr,
m_fileName));
}
}
else
{
try
{
Object objValue = null;
// Normally, either tfi.typeConverter is not null,
// or tfi.parseNumberMethod is not null.
//
if (tfi.typeConverter != null)
{
objValue = tfi.typeConverter.ConvertFromString(
null,
m_fileDescription.FileCultureInfo,
value);
}
else if (tfi.parseExactMethod != null)
{
objValue =
tfi.parseExactMethod.Invoke(
tfi.fieldType,
new Object[] {
value,
tfi.outputFormat,
m_fileDescription.FileCultureInfo
});
}
else if (tfi.parseNumberMethod != null)
{
objValue =
tfi.parseNumberMethod.Invoke(
tfi.fieldType,
new Object[] {
value,
tfi.inputNumberStyle,
m_fileDescription.FileCultureInfo
});
}
else
{
// No TypeConverter and no Parse method available.
// Try direct approach.
objValue = value;
}
if (tfi.memberInfo is PropertyInfo)
{
((PropertyInfo)tfi.memberInfo).SetValue(obj, objValue, null);
}
else
{
((FieldInfo)tfi.memberInfo).SetValue(obj, objValue);
}
}
catch (Exception e)
{
if (e is TargetInvocationException)
{
e = e.InnerException;
}
if (e is FormatException)
{
e = new WrongDataFormatException(
typeof(T).ToString(),
tfi.name,
value,
row[i].LineNbr,
m_fileName,
e);
}
ae.AddException(e);
}
}
}
// Visit any remaining fields in the type for which no value was given
// in the data row, to see whether any of those was required.
// If only looking at fields with CsvColumn attribute, do ignore
// fields that don't have that attribute.
for (int i = row.Count; i < m_IndexToInfo.Length; i++)
{
TypeFieldInfo tfi = m_IndexToInfo[i];
if (((!m_fileDescription.EnforceCsvColumnAttribute) ||
tfi.hasColumnAttribute) &&
(!tfi.canBeNull))
{
ae.AddException(
new MissingRequiredFieldException(
typeof(T).ToString(),
tfi.name,
row[row.Count - 1].LineNbr,
m_fileName));
}
}
return(obj);
}
/// ///////////////////////////////////////////////////////////////////////
/// ReadObject
/// <summary>
/// Creates an object of type T from the data in row and returns that object.
/// </summary>
/// <param name="row"></param>
/// <param name="firstRow"></param>
/// <returns></returns>
public T ReadObject(IDataRow row, AggregatedException ae)
{
//If there are more columns than the required
if (row.Count > m_IndexToInfo.Length)
{
if (!m_fileDescription.IgnoreUnknownColumns)
{
throw new TooManyDataFieldsException(typeof(T).ToString(), row[0].LineNbr, m_fileName);
}
}
// -----
var obj = new T();
//If we will be using the mappings, we just iterate through all the cells in this row
var maxRowCount = _mappingIndexes.Count > 0 ? row.Count : Math.Min(row.Count, m_IndexToInfo.Length);
for (var i = 0; i < maxRowCount; i++)
{
TypeFieldInfo tfi;
//If there is some index mapping generated and the IgnoreUnknownColums is `true`
if (m_fileDescription.IgnoreUnknownColumns && _mappingIndexes.Count > 0)
{
if (!_mappingIndexes.ContainsKey(i))
{
continue;
}
tfi = m_IndexToInfo[_mappingIndexes[i]];
}
else
{
tfi = m_IndexToInfo[i];
}
if (m_fileDescription.EnforceCsvColumnAttribute &&
!tfi.hasColumnAttribute)
{
throw new TooManyNonCsvColumnDataFieldsException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
// -----
if (!m_fileDescription.FirstLineHasColumnNames &&
tfi.index == CsvColumnAttribute.mc_DefaultFieldIndex)
{
throw new MissingFieldIndexException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
// -----
if (m_fileDescription.UseFieldIndexForReadingData && !m_fileDescription.FirstLineHasColumnNames &&
tfi.index > row.Count)
{
throw new WrongFieldIndexException(typeof(T).ToString(), row[i].LineNbr, m_fileName);
}
var index = m_fileDescription.UseFieldIndexForReadingData ? tfi.index - 1 : i;
// value to put in the object
var value = row[index].Value;
if (value == null)
{
if (!tfi.canBeNull)
{
ae.AddException(
new MissingRequiredFieldException(
typeof(T).ToString(),
tfi.name,
row[i].LineNbr,
m_fileName));
}
}
else
{
try
{
object objValue = null;
// Normally, either tfi.typeConverter is not null,
// or tfi.parseNumberMethod is not null.
//
if (tfi.typeConverter != null)
{
objValue = tfi.typeConverter.ConvertFromString(
null,
m_fileDescription.FileCultureInfo,
value);
}
else if (tfi.parseExactMethod != null)
{
objValue =
tfi.parseExactMethod.Invoke(
tfi.fieldType,
new object[]
{
value,
tfi.outputFormat,
m_fileDescription.FileCultureInfo
});
}
else if (tfi.parseNumberMethod != null)
{
objValue =
tfi.parseNumberMethod.Invoke(
tfi.fieldType,
new object[]
{
value,
tfi.inputNumberStyle,
m_fileDescription.FileCultureInfo
});
}
else
{
objValue = value;
}
switch (tfi.memberInfo)
{
case PropertyInfo property:
property.SetValue(obj, objValue, null);
break;
case FieldInfo field:
field.SetValue(obj, objValue);
break;
}
}
catch (Exception e)
{
if (e is TargetInvocationException)
{
e = e.InnerException;
}
if (e is FormatException)
{
e = new WrongDataFormatException(
typeof(T).ToString(),
tfi.name,
value,
row[i].LineNbr,
m_fileName,
e);
}
ae.AddException(e);
}
}
}
// Visit any remaining fields in the type for which no value was given
// in the data row, to see whether any of those was required.
// If only looking at fields with CsvColumn attribute, do ignore
// fields that don't have that attribute.
for (var i = row.Count; i < m_IndexToInfo.Length; i++)
{
var tfi = m_IndexToInfo[i];
if ((!m_fileDescription.EnforceCsvColumnAttribute ||
tfi.hasColumnAttribute) &&
!tfi.canBeNull)
{
ae.AddException(
new MissingRequiredFieldException(
typeof(T).ToString(),
tfi.name,
row[row.Count - 1].LineNbr,
m_fileName));
}
}
return(obj);
}
