/// <summary>
/// Asynchronously writes all rows in <paramref name="this"/> to <paramref name="csvWriter"/>.
/// </summary>
/// <remarks>
/// </remarks>
/// <param name="this">
/// The <see cref="DataTable"/>.
/// </param>
/// <param name="csvWriter">
/// The <see cref="CsvWriter"/>.
/// </param>
/// <param name="writeHeaderRecord">
/// If <see langword="true"/>, a header record will also be written, which will be comprised of the column names defined for <paramref name="this"/>.
/// </param>
/// <param name="maximumRows">
/// The maximum number of rows from <paramref name="this"/> that should be written to <paramref name="csvWriter"/>.
/// </param>
/// <param name="objectToStringConverter">
/// Provides a means of converting values in the <see cref="DataRow"/>s to <see cref="String"/>s.
/// </param>
/// <returns>
/// The actual number of rows from <paramref name="this"/> written to <paramref name="csvWriter"/>.
/// </returns>
public async static Task <int> WriteCsvAsync(this DataTable @this, CsvWriter csvWriter, bool writeHeaderRecord, int?maximumRows, Func <object, string> objectToStringConverter)
{
@this.AssertNotNull("@this");
csvWriter.AssertNotNull("csvWriter");
objectToStringConverter.AssertNotNull("objectToStringConverter");
var num = 0;
if (writeHeaderRecord)
{
var columnNames = new string[@this.Columns.Count];
for (var i = 0; i < columnNames.Length; ++i)
{
columnNames[i] = @this.Columns[i].ColumnName;
}
await csvWriter.WriteRecordAsync(columnNames).ConfigureAwait(false);
}
var maximum = maximumRows.GetValueOrDefault(int.MaxValue);
var buffer = new DataRecord[16];
var bufferOffset = 0;
foreach (DataRow row in @this.Rows)
{
var record = new DataRecord();
for (var i = 0; i < row.ItemArray.Length; ++i)
{
record.Add(objectToStringConverter(row.ItemArray[i]));
}
buffer[bufferOffset++] = record;
if (bufferOffset == buffer.Length)
{
// buffer full
await csvWriter.WriteRecordsAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
bufferOffset = 0;
}
if (++num == maximum)
{
break;
}
}
// write any outstanding data in buffer
await csvWriter.WriteRecordsAsync(buffer, 0, bufferOffset).ConfigureAwait(false);
return(num);
}
/// <summary>
/// Asynchronously writes the items in <paramref name="this"/> to <paramref name="csvWriter"/>.
/// </summary>
/// <remarks>
/// <para>
/// This overload provides maximum flexibility in how items are written CSV.
/// </para>
/// </remarks>
/// <typeparam name="T">
/// The type of the items to be written to <paramref name="csvWriter"/>.
/// </typeparam>
/// <param name="this">
/// The items to write.
/// </param>
/// <param name="csvWriter">
/// The <see cref="CsvWriter"/>.
/// </param>
/// <param name="header">
/// If non-<see langword="null"/>, this will be written to <paramref name="csvWriter"/> before any data records are written.
/// </param>
/// <param name="objectToRecordConverter">
/// Converts an item in <paramref name="this"/> to a CSV record.
/// </param>
/// <returns>
/// The number of items written.
/// </returns>
public async static Task <int> WriteCsvAsync <T>(this IEnumerable <T> @this, CsvWriter csvWriter, IEnumerable <string> header, Func <T, IEnumerable <string> > objectToRecordConverter)
{
@this.AssertNotNull("@this");
csvWriter.AssertNotNull("csvWriter");
objectToRecordConverter.AssertNotNull("objectToRecordConverter");
HeaderRecord headerRecord = null;
if (header != null)
{
headerRecord = new HeaderRecord(header);
await csvWriter.WriteRecordAsync(headerRecord).ConfigureAwait(false);
}
var num = 0;
var buffer = new DataRecord[16];
var bufferOffset = 0;
foreach (var item in @this)
{
var record = new DataRecord(headerRecord, objectToRecordConverter(item));
buffer[bufferOffset++] = record;
if (bufferOffset == buffer.Length)
{
// buffer full
await csvWriter.WriteRecordsAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
bufferOffset = 0;
}
++num;
}
// write any outstanding data in buffer
await csvWriter.WriteRecordsAsync(buffer, 0, bufferOffset).ConfigureAwait(false);
return(num);
}
/// <summary>
/// Asynchronously copies all remaining records in <paramref name="this"/> to <paramref name="destination"/>.
/// </summary>
/// <param name="this">
/// The data source.
/// </param>
/// <param name="destination">
/// The data destination.
/// </param>
/// <returns>
/// The number of records written to <paramref name="destination"/>.
/// </returns>
public async static Task<int> CopyToAsync(this CsvReader @this, CsvWriter destination)
{
@this.AssertNotNull("@this");
destination.AssertNotNull("destination");
var num = 0;
var buffer = new DataRecord[16];
var read = 0;
while ((read = await @this.ReadDataRecordsAsync(buffer, 0, buffer.Length).ConfigureAwait(false)) != 0)
{
await destination.WriteRecordsAsync(buffer, 0, read).ConfigureAwait(false);
num += read;
}
return num;
}
/// <summary>
/// Asynchronously copies all remaining records in <paramref name="this"/> to <paramref name="destination"/>.
/// </summary>
/// <param name="this">
/// The data source.
/// </param>
/// <param name="destination">
/// The data destination.
/// </param>
/// <returns>
/// The number of records written to <paramref name="destination"/>.
/// </returns>
public async static Task <int> CopyToAsync(this CsvReader @this, CsvWriter destination)
{
@this.AssertNotNull("@this");
destination.AssertNotNull("destination");
var num = 0;
var buffer = new DataRecord[16];
var read = 0;
while ((read = await @this.ReadDataRecordsAsync(buffer, 0, buffer.Length).ConfigureAwait(false)) != 0)
{
await destination.WriteRecordsAsync(buffer, 0, read).ConfigureAwait(false);
num += read;
}
return(num);
}
/// <summary>
/// Asynchronously writes all rows in <paramref name="this"/> to <paramref name="csvWriter"/>.
/// </summary>
/// <remarks>
/// </remarks>
/// <param name="this">
/// The <see cref="DataTable"/>.
/// </param>
/// <param name="csvWriter">
/// The <see cref="CsvWriter"/>.
/// </param>
/// <param name="writeHeaderRecord">
/// If <see langword="true"/>, a header record will also be written, which will be comprised of the column names defined for <paramref name="this"/>.
/// </param>
/// <param name="maximumRows">
/// The maximum number of rows from <paramref name="this"/> that should be written to <paramref name="csvWriter"/>.
/// </param>
/// <param name="objectToStringConverter">
/// Provides a means of converting values in the <see cref="DataRow"/>s to <see cref="String"/>s.
/// </param>
/// <returns>
/// The actual number of rows from <paramref name="this"/> written to <paramref name="csvWriter"/>.
/// </returns>
public async static Task<int> WriteCsvAsync(this DataTable @this, CsvWriter csvWriter, bool writeHeaderRecord, int? maximumRows, Func<object, string> objectToStringConverter)
{
@this.AssertNotNull("@this");
csvWriter.AssertNotNull("csvWriter");
objectToStringConverter.AssertNotNull("objectToStringConverter");
var num = 0;
if (writeHeaderRecord)
{
var columnNames = new string[@this.Columns.Count];
for (var i = 0; i < columnNames.Length; ++i)
{
columnNames[i] = @this.Columns[i].ColumnName;
}
await csvWriter.WriteRecordAsync(columnNames).ConfigureAwait(false);
}
var maximum = maximumRows.GetValueOrDefault(int.MaxValue);
var buffer = new DataRecord[16];
var bufferOffset = 0;
foreach (DataRow row in @this.Rows)
{
var record = new DataRecord();
for (var i = 0; i < row.ItemArray.Length; ++i)
{
record.Add(objectToStringConverter(row.ItemArray[i]));
}
buffer[bufferOffset++] = record;
if (bufferOffset == buffer.Length)
{
// buffer full
await csvWriter.WriteRecordsAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
bufferOffset = 0;
}
if (++num == maximum)
{
break;
}
}
// write any outstanding data in buffer
await csvWriter.WriteRecordsAsync(buffer, 0, bufferOffset).ConfigureAwait(false);
return num;
}
private async static Task ReadCSVFromFileAndWriteToTabDelimitedFile()
{
#region ReadCSVFromFileAndWriteToTabDelimitedFile
using (var streamReader = new StreamReader("PlanetaryData.csv"))
using (var reader = new CsvReader(streamReader))
using (var streamWriter = new StreamWriter("PlanetaryData_Modified.csv"))
using (var writer = new CsvWriter(streamWriter))
{
writer.ValueSeparator = '\t';
writer.ValueDelimiter = '\'';
// realistically, you'll probably want a larger buffer, but this suffices for demonstration purposes
var buffer = new DataRecord[4];
while (reader.HasMoreRecords)
{
var read = await reader.ReadDataRecordsAsync(buffer, 0, buffer.Length);
await writer.WriteRecordsAsync(buffer, 0, read);
}
}
#endregion
}