/// <summary>
/// Parse a single row of data from a CSV line into an array of objects, while permitting embedded newlines
/// </summary>
/// <param name="inStream">The stream to read</param>
/// <param name="settings">The CSV settings to use for this parsing operation (Default: CSV)</param>
/// <returns>An array containing all fields in the next row of data, or null if it could not be parsed.</returns>
public static string[] ParseMultiLine(StreamReader inStream, CSVSettings settings = null)
{
StringBuilder sb = new StringBuilder();
string[] array = null;
while (!inStream.EndOfStream)
{
// Read in a line
sb.Append(inStream.ReadLine());
// Does it parse?
string s = sb.ToString();
if (TryParseLine(s, out array, settings))
{
return(array);
}
// We didn't succeed on the first try - our text must have an embedded newline in it.
// Let's assume that we were in the middle of parsing a field when we encountered a newline,
// and continue parsing.
sb.Append(settings.LineSeparator);
}
// Fails to parse - return the best array we were able to get
return(array);
}
/// <summary>
/// Appends a single object to a StringBuilder in CSV format as a single line
/// </summary>
/// <param name="sb">The stringbuilder to append data</param>
/// <param name="obj">The single object to append in CSV-line format</param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
/// <typeparam name="T">The 1st type parameter.</typeparam>
public static void AppendAsCSV <T>(this StringBuilder sb, T obj, CSVSettings settings = null) where T : class, new()
{
// Skip any null objects
if (obj == null)
{
return;
}
// Use CSV as default.
if (settings == null)
{
settings = CSVSettings.CSV;
}
// Retrieve reflection information
var type = typeof(T);
var filist = type.GetFields();
var pilist = type.GetProperties();
// Retrieve all the fields and properties
List <object> values = new List <object>();
foreach (var fi in filist)
{
values.Add(fi.GetValue(obj));
}
foreach (var pi in pilist)
{
values.Add(pi.GetValue(obj, null));
}
// Output one line of CSV
AppendCSVRow(sb, values, settings);
}
/// <summary>
/// Write the data table to a stream in CSV format
/// </summary>
/// <param name="dt">The data table to write</param>
/// <param name="sw">The stream where the CSV text will be written</param>
/// <param name="settings">The CSV settings to use when exporting this DataTable (Default: CSV)</param>
public static void WriteToStream(this DataTable dt, StreamWriter sw, CSVSettings settings = null)
{
using (CSVWriter cw = new CSVWriter(sw, settings))
{
cw.Write(dt);
}
}
/// <summary>
/// Serialize an array of objects to CSV format
/// </summary>
/// <typeparam name="T">The type of objects to serialize from this CSV</typeparam>
/// <param name="list">The array of objects to serialize</param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
/// <returns>The completed CSV string representing one line per element in list</returns>
public static string Serialize <T>(IEnumerable <T> list, CSVSettings settings = null) where T : class, new()
{
// Use CSV as default.
if (settings == null)
{
settings = CSVSettings.CSV;
}
// Okay, let's begin
StringBuilder sb = new StringBuilder();
// Did the caller want the header row?
if (settings.HeaderRowIncluded)
{
sb.AppendCSVHeader(typeof(T), settings);
sb.Append(settings.LineSeparator);
}
// Let's go through the array of objects
// Iterate through all the objects
var values = new List <object>();
foreach (T obj in list)
{
sb.AppendAsCSV <T>(obj, settings);
sb.Append(settings.LineSeparator);
}
// Here's your data serialized in CSV format
return(sb.ToString());
}
/// <summary>
/// Add a CSV Header line to a StringBuilder
/// </summary>
/// <param name="sb">The stringbuilder to append data</param>
/// <param name="type">The type of data to emit a header</param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
public static void AppendCSVHeader(this StringBuilder sb, Type type, CSVSettings settings = null)
{
// Use CSV as default.
if (settings == null)
{
settings = CSVSettings.CSV;
}
// Retrieve reflection information
var filist = type.GetFields();
var pilist = type.GetProperties();
// Gather information about headers
var headers = new List <object>();
foreach (var fi in filist)
{
headers.Add(fi.Name);
}
foreach (var pi in pilist)
{
headers.Add(pi.Name);
}
AppendCSVRow(sb, headers, settings);
}
/// <summary>
/// Read in a single CSV file into a datatable in memory
/// </summary>
/// <param name="stream">The stream source from which to load the datatable.</param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
/// <returns>An data table of strings that were retrieved from the CSV file.</returns>
public static DataTable FromStream(StreamReader stream, CSVSettings settings = null)
{
using (CSVReader cr = new CSVReader(stream, settings))
{
return(cr.ReadAsDataTable());
}
}
/// <summary>
/// Serialize a sequence of objects into a CSV string
/// </summary>
/// <returns>A single line of CSV encoded data containing these values</returns>
/// <param name="row">A list or array of objects to serialize</param>
/// <param name="settings">The field delimiter character (Default: comma)</param>
public static string ToCSVString(this IEnumerable <object> row, CSVSettings settings = null)
{
StringBuilder sb = new StringBuilder();
AppendCSVRow(sb, row, settings);
return(sb.ToString());
}
/// <summary>
/// Read in a single CSV file into a datatable in memory
/// </summary>
/// <param name="filename"></param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
/// <returns>An data table of strings that were retrieved from the CSV file.</returns>
public static DataTable FromFile(string filename, CSVSettings settings = null)
{
using (var sr = new StreamReader(filename))
{
return(FromStream(sr, settings));
}
}
/// <summary>
/// Read in a single CSV file as an array of objects
/// </summary>
/// <typeparam name="T">The type of objects to deserialize from this CSV.</typeparam>
/// <param name="stream">The stream to read.</param>
/// <param name="settings">The CSV settings to use when loading this array (Default: CSV)</param>
/// <returns>An array of objects that were retrieved from the CSV file.</returns>
public static List <T> LoadArray <T>(StreamReader stream, CSVSettings settings) where T : class, new()
{
using (CSVReader cr = new CSVReader(stream, settings))
{
return(cr.Deserialize <T>());
}
}
/// <summary>
/// Write a data table to disk at the designated file name in CSV format
/// </summary>
/// <param name="dt"></param>
/// <param name="filename"></param>
/// <param name="settings">The CSV settings to use when exporting this DataTable (Default: CSV)</param>
public static void WriteToFile(this DataTable dt, string filename, CSVSettings settings = null)
{
using (StreamWriter sw = new StreamWriter(filename))
{
WriteToStream(dt, sw, settings);
}
}
/// <summary>
/// Construct a new CSV writer to produce output on the enclosed StreamWriter
/// </summary>
/// <param name="dest">The stream where this CSV will be outputted</param>
/// <param name="settings">The CSV settings to use when writing to the stream (Default: CSV)</param>
public CSVWriter(StreamWriter dest, CSVSettings settings = null)
{
_outstream = dest;
_settings = settings;
if (_settings == null)
{
_settings = CSVSettings.CSV;
}
}
/// <summary>
/// Deserialize a CSV string into a list of typed objects
/// </summary>
/// <typeparam name="T">The type of objects to deserialize</typeparam>
/// <param name="settings">The CSV settings to use when parsing the source (Default: CSV)</param>
/// <param name="source">The source CSV to deserialize</param>
/// <returns></returns>
public static List <T> Deserialize <T>(string source, CSVSettings settings = null) where T : class, new()
{
byte[] byteArray = Encoding.UTF8.GetBytes(source);
using (var stream = new MemoryStream(byteArray))
{
using (CSVReader cr = new CSVReader(new StreamReader(stream), settings))
{
return(cr.Deserialize <T>());
}
}
}
/// <summary>
/// Convert a CSV file (in string form) into a data table
/// </summary>
/// <param name="source"></param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
/// <returns></returns>
public static DataTable FromString(string source, CSVSettings settings = null)
{
byte[] byteArray = Encoding.UTF8.GetBytes(source);
using (MemoryStream stream = new MemoryStream(byteArray))
{
using (CSVReader cr = new CSVReader(new StreamReader(stream), settings))
{
return(cr.ReadAsDataTable());
}
}
}
/// <summary>
/// Add a single token to the list
/// </summary>
/// <param name="list">List.</param>
/// <param name="work">Work.</param>
/// <param name="settings">Settings.</param>
private static void AddToken(List <string> list, StringBuilder work, CSVSettings settings)
{
var s = work.ToString();
if (settings.AllowNull && String.Equals(s, settings.NullToken, StringComparison.Ordinal))
{
list.Add(null);
}
else
{
list.Add(s);
}
work.Length = 0;
}
/// <summary>
/// Convert a CSV file (in string form) into a list of string arrays
/// </summary>
/// <param name="source_string"></param>
/// <param name="settings">The CSV settings to use when loading this array (Default: CSV)</param>
/// <returns></returns>
public static List <string[]> LoadString(string source_string, CSVSettings settings = null)
{
byte[] byteArray = Encoding.UTF8.GetBytes(source_string);
MemoryStream stream = new MemoryStream(byteArray);
var results = new List <string[]>();
using (CSVReader cr = new CSVReader(new StreamReader(stream))) {
foreach (var line in cr)
{
results.Add(line);
}
}
return(results);
}
/// <summary>
/// Write a DataTable to a string in CSV format
/// </summary>
/// <param name="dt">The datatable to write</param>
/// <param name="settings">The CSV settings to use when exporting this DataTable (Default: CSV)</param>
/// <returns>The CSV string representing the object array.</returns>
public static string WriteToString(this DataTable dt, CSVSettings settings = null)
{
using (var ms = new MemoryStream())
{
var sw = new StreamWriter(ms);
var cw = new CSVWriter(sw, settings);
cw.Write(dt);
sw.Flush();
ms.Position = 0;
using (var sr = new StreamReader(ms))
{
return(sr.ReadToEnd());
}
}
}
/// <summary>
/// Construct a new CSV reader off a streamed source
/// </summary>
/// <param name="source">The stream source</param>
/// <param name="settings">The CSV settings to use for this reader (Default: CSV)</param>
public CSVReader(StreamReader source, CSVSettings settings = null)
{
_instream = source;
_settings = settings;
if (_settings == null)
{
_settings = CSVSettings.CSV;
}
// Do we need to parse headers?
if (_settings.HeaderRowIncluded)
{
Headers = NextLine();
}
else
{
Headers = _settings.AssumedHeaders?.ToArray();
}
}
/// <summary>
/// Append an array of objects to a StringBuilder in CSV format
/// </summary>
/// <param name="sb">The StringBuilder to append</param>
/// <param name="row">The list of objects to append</param>
/// <param name="settings">The CSV settings to use when exporting this array (Default: CSV)</param>
private static void AppendCSVRow(this StringBuilder sb, IEnumerable <object> row, CSVSettings settings = null)
{
// Use CSV as default.
if (settings == null)
{
settings = CSVSettings.CSV;
}
var q = settings.TextQualifier.ToString();
// Okay, let's begin
foreach (object o in row)
{
// If this is null, check our settings for what they want us to do
if (o == null)
{
if (settings.AllowNull)
{
sb.Append(settings.NullToken);
sb.Append(settings.FieldDelimiter);
}
continue;
}
// Okay, let's handle this value normally
string s = o.ToString();
if (s.Length > 0)
{
// Does this string contain any risky characters? Risky is defined as delim, qual, or newline
if (settings.ForceQualifiers || (s.IndexOf(settings.FieldDelimiter) >= 0) || (s.IndexOf(settings.TextQualifier) >= 0) || s.Contains(settings.LineSeparator))
{
sb.Append(q);
// Double up any qualifiers that may occur
sb.Append(s.Replace(q, q + q));
sb.Append(q);
}
else
{
sb.Append(s);
}
}
// Move to the next cell
sb.Append(settings.FieldDelimiter);
}
// Subtract the trailing delimiter so we don't inadvertently add an empty column at the end
sb.Length -= 1;
}
/// <summary>
/// Read in a single CSV file as an array of objects
/// </summary>
/// <typeparam name="T">The type of objects to deserialize from this CSV.</typeparam>
/// <param name="filename">The path of the file to read.</param>
/// <param name="settings">The CSV settings to use when loading this array (Default: CSV)</param>
/// <returns>An array of objects that were retrieved from the CSV file.</returns>
public static List <T> LoadArray <T>(string filename, CSVSettings settings = null) where T : class, new()
{
return(LoadArray <T>(new StreamReader(filename), settings));
}
/// <summary>
/// Serialize an object array to a stream in CSV format
/// </summary>
/// <param name="list">The object array to write</param>
/// <param name="filename">The stream where the CSV text will be written</param>
/// <param name="settings">The CSV settings to use when writing the output (Default: CSV)</param>
public static void WriteToStream <T>(this IEnumerable <T> list, string filename, CSVSettings settings = null) where T : class, new()
{
using (StreamWriter sw = new StreamWriter(filename))
{
WriteToStream <T>(list, sw, settings);
}
}
/// <summary>
/// Serialize an object array to a stream in CSV format
/// </summary>
/// <param name="list">The object array to write</param>
/// <param name="sw">The stream where the CSV text will be written</param>
/// <param name="settings">The CSV settings to use (Default: CSV)</param>
public static void WriteToStream <T>(this IEnumerable <T> list, StreamWriter sw, CSVSettings settings = null) where T : class, new()
{
using (CSVWriter cw = new CSVWriter(sw, settings))
{
cw.WriteArray <T>(list);
}
}
/// <summary>
/// Parse a line from a CSV file and return an array of fields, or null if
/// </summary>
/// <param name="line">One line of text from a CSV file</param>
/// <param name="settings">The CSV settings to use for this parsing operation (Default: CSV)</param>
/// <returns>An array containing all fields in the next row of data, or null if it could not be parsed.</returns>
public static string[] ParseLine(string line, CSVSettings settings = null)
{
TryParseLine(line, out string[] row, settings);
return(row);
}
/// <summary>
/// Take a CSV file and chop it into multiple chunks of a specified maximum size.
/// </summary>
/// <param name="filename">The input filename to chop</param>
/// <param name="out_folder">The folder where the chopped CSV will be saved</param>
/// <param name="maxLinesPerFile">The maximum number of lines to put into each file</param>
/// <param name="settings">The CSV settings to use when chopping this file into chunks (Default: CSV)</param>
/// <returns>Number of files chopped</returns>
public static int ChopFile(string filename, string out_folder, int maxLinesPerFile, CSVSettings settings = null)
{
// Default settings
if (settings == null)
{
settings = CSVSettings.CSV;
}
// Let's begin parsing
int file_id = 1;
int line_count = 0;
string file_prefix = Path.GetFileNameWithoutExtension(filename);
string ext = Path.GetExtension(filename);
CSVWriter cw = null;
StreamWriter sw = null;
// Read in lines from the file
using (var sr = new StreamReader(filename))
{
using (CSVReader cr = new CSVReader(sr, settings))
{
// Okay, let's do the real work
foreach (string[] line in cr.Lines())
{
// Do we need to create a file for writing?
if (cw == null)
{
string fn = Path.Combine(out_folder, file_prefix + file_id.ToString() + ext);
sw = new StreamWriter(fn);
cw = new CSVWriter(sw, settings);
if (settings.HeaderRowIncluded)
{
cw.WriteLine(cr.Headers);
}
}
// Write one line
cw.WriteLine(line);
// Count lines - close the file if done
line_count++;
if (line_count >= maxLinesPerFile)
{
cw.Dispose();
cw = null;
file_id++;
line_count = 0;
}
}
}
}
// Ensore the final CSVWriter is closed properly
if (cw != null)
{
cw.Dispose();
cw = null;
}
return(file_id);
}
/// <summary>
/// Try to parse a line of CSV data. Can only return false if an unterminated text qualifier is encountered.
/// </summary>
/// <returns>False if there was an unterminated text qualifier in the <paramref name="line"/></returns>
/// <param name="line">The line of text to parse</param>
/// <param name="settings">The CSV settings to use for this parsing operation (Default: CSV)</param>
/// <param name="row">The array of fields found in the line</param>
public static bool TryParseLine(string line, out string[] row, CSVSettings settings = null)
{
// Ensure settings are non-null
if (settings == null)
{
settings = CSVSettings.CSV;
}
// Okay, let's begin parsing
List <string> list = new List <string>();
var work = new StringBuilder();
for (int i = 0; i < line.Length; i++)
{
char c = line[i];
// If we are starting a new field, is this field text qualified?
if ((c == settings.TextQualifier) && (work.Length == 0))
{
int p2;
while (true)
{
p2 = line.IndexOf(settings.TextQualifier, i + 1);
// If no closing qualifier is found, this string is broken; return failure.
if (p2 < 0)
{
work.Append(line.Substring(i + 1));
list.Add(work.ToString());
row = list.ToArray();
return(false);
}
// Append this qualified string
work.Append(line.Substring(i + 1, p2 - i - 1));
i = p2;
// If this is a double quote, keep going!
if (((p2 + 1) < line.Length) && (line[p2 + 1] == settings.TextQualifier))
{
work.Append(settings.TextQualifier);
i++;
// otherwise, this is a single qualifier, we're done
}
else
{
break;
}
}
// Does this start a new field?
}
else if (c == settings.FieldDelimiter)
{
// Is this a null token, and do we permit null tokens?
AddToken(list, work, settings);
// Test for special case: when the user has written a casual comma, space, and text qualifier, skip the space
// Checks if the second parameter of the if statement will pass through successfully
// e.g. "bob", "mary", "bill"
if (i + 2 <= line.Length - 1)
{
if (line[i + 1].Equals(' ') && line[i + 2].Equals(settings.TextQualifier))
{
i++;
}
}
}
else
{
work.Append(c);
}
}
AddToken(list, work, settings);
// Return the array we parsed
row = list.ToArray();
return(true);
}