//CsvExport - V2.0
using System;
using System.Collections.Generic;
using System.Data.SqlTypes;
using System.IO;
using System.Linq;
using System.Text;
namespace Jitbit.Utils
{
/// <summary>
/// Simple CSV export
/// Example:
/// CsvExport myExport = new CsvExport();
///
/// myExport.AddRow();
/// myExport["Region"] = "New York, USA";
/// myExport["Sales"] = 100000;
/// myExport["Date Opened"] = new DateTime(2003, 12, 31);
///
/// myExport.AddRow();
/// myExport["Region"] = "Sydney \"in\" Australia";
/// myExport["Sales"] = 50000;
/// myExport["Date Opened"] = new DateTime(2005, 1, 1, 9, 30, 0);
///
/// Then you can do any of the following three output options:
/// string myCsv = myExport.Export();
/// myExport.ExportToFile("Somefile.csv");
/// byte[] myCsvData = myExport.ExportToBytes();
/// </summary>
public class CsvExport
{
/// <summary>
/// To keep the ordered list of column names
/// </summary>
List<string> _fields = new List<string>();
/// <summary>
/// The list of rows
/// </summary>
List<Dictionary<string, object>> _rows = new List<Dictionary<string, object>>();
/// <summary>
/// The current row
/// </summary>
Dictionary<string, object> _currentRow { get { return _rows[_rows.Count - 1]; } }
/// <summary>
/// The string used to separate columns in the output
/// </summary>
private readonly string _columnSeparator;
/// <summary>
/// Whether to include the preamble that declares which column separator is used in the output
/// </summary>
private readonly bool _includeColumnSeparatorDefinitionPreamble;
/// <summary>
/// Initializes a new instance of the <see cref="Jitbit.Utils.CsvExport"/> class.
/// </summary>
/// <param name="columnSeparator">
/// The string used to separate columns in the output.
/// By default this is a comma so that the generated output is a CSV file.
/// </param>
/// <param name="includeColumnSeparatorDefinitionPreamble">
/// Whether to include the preamble that declares which column separator is used in the output.
/// By default this is <c>true</c> so that Excel can open the generated CSV
/// without asking the user to specify the delimiter used in the file.
/// </param>
public CsvExport(string columnSeparator=",", bool includeColumnSeparatorDefinitionPreamble=true)
{
_columnSeparator = columnSeparator;
_includeColumnSeparatorDefinitionPreamble = includeColumnSeparatorDefinitionPreamble;
}
/// <summary>
/// Set a value on this column
/// </summary>
public object this[string field]
{
set
{
// Keep track of the field names, because the dictionary loses the ordering
if (!_fields.Contains(field)) _fields.Add(field);
_currentRow[field] = value;
}
}
/// <summary>
/// Call this before setting any fields on a row
/// </summary>
public void AddRow()
{
_rows.Add(new Dictionary<string, object>());
}
/// <summary>
/// Add a list of typed objects, maps object properties to CsvFields
/// </summary>
public void AddRows<T>(IEnumerable<T> list)
{
if (list.Any())
{
foreach (var obj in list)
{
AddRow();
var values = obj.GetType().GetProperties();
foreach (var value in values)
{
this[value.Name] = value.GetValue(obj, null);
}
}
}
}
/// <summary>
/// Converts a value to how it should output in a csv file
/// If it has a comma, it needs surrounding with double quotes
/// Eg Sydney, Australia -> "Sydney, Australia"
/// Also if it contains any double quotes ("), then they need to be replaced with quad quotes[sic] ("")
/// Eg "Dangerous Dan" McGrew -> """Dangerous Dan"" McGrew"
/// </summary>
/// <param name="columnSeparator">
/// The string used to separate columns in the output.
/// By default this is a comma so that the generated output is a CSV document.
/// </param>
public static string MakeValueCsvFriendly(object value, string columnSeparator=",")
{
if (value == null) return "";
if (value is INullable && ((INullable)value).IsNull) return "";
if (value is DateTime)
{
if (((DateTime)value).TimeOfDay.TotalSeconds == 0)
return ((DateTime)value).ToString("yyyy-MM-dd");
return ((DateTime)value).ToString("yyyy-MM-dd HH:mm:ss");
}
string output = value.ToString().Trim();
if (output.Contains(columnSeparator) || output.Contains("\"") || output.Contains("\n") || output.Contains("\r"))
output = '"' + output.Replace("\"", "\"\"") + '"';
if (output.Length > 30000) //cropping value for stupid Excel
{
if (output.EndsWith("\""))
{
output = output.Substring(0, 30000);
if(output.EndsWith("\"") && !output.EndsWith("\"\"")) //rare situation when cropped line ends with a '"'
output += "\""; //add another '"' to escape it
output += "\"";
}
else
output = output.Substring(0, 30000);
}
return output;
}
/// <summary>
/// Outputs all rows as a CSV, returning one string at a time
/// </summary>
private IEnumerable<string> ExportToLines()
{
if (_includeColumnSeparatorDefinitionPreamble) yield return "sep=" + _columnSeparator;
// The header
yield return string.Join(_columnSeparator, _fields.Select(f => MakeValueCsvFriendly(f, _columnSeparator)));
// The rows
foreach (Dictionary<string, object> row in _rows)
{
foreach (string k in _fields.Where(f => !row.ContainsKey(f)))
{
row[k] = null;
}
yield return string.Join(_columnSeparator, _fields.Select(field => MakeValueCsvFriendly(row[field], _columnSeparator)));
}
}
/// <summary>
/// Output all rows as a CSV returning a string
/// </summary>
public string Export()
{
StringBuilder sb = new StringBuilder();
foreach (string line in ExportToLines())
{
sb.AppendLine(line);
}
return sb.ToString();
}
/// <summary>
/// Exports to a file
/// </summary>
public void ExportToFile(string path)
{
File.WriteAllLines(path, ExportToLines(), Encoding.UTF8);
}
/// <summary>
/// Exports as raw UTF8 bytes
/// </summary>
public byte[] ExportToBytes()
{
var data = Encoding.UTF8.GetBytes(Export());
return Encoding.UTF8.GetPreamble().Concat(data).ToArray();
}
}
}