private bool Read()
{
if (!_isHeaderReaded)
{
ReadHeaderRow();
_isHeaderReaded = true;
}
if (Reader.EndOfStream)
{
return(false);
}
var fields = ReadRow();
if (fields.Length != _headers.Count)
{
throw new CsvReadingException("Invalid row. Fields are not accepts to headers");
}
CurrentRecord = new CsvRecord();
for (var i = 0; i < _headers.Count; i++)
{
CurrentRecord.Add(_headers.ElementAt(i), fields[i]);
}
return(true);
}
/// <summary>
/// Parses the line into a list of strings.
/// </summary>
/// <param name="line">The line.</param>
/// <returns></returns>
public static CsvRecord ParseLine(string line)
{
var values = new CsvRecord();
var currentValue = new StringBuilder(1024);
char currentChar;
Nullable <char> nextChar = null;
var currentState = ReadState.WaitingForNewField;
for (var charIndex = 0; charIndex < line.Length; charIndex++)
{
// Get the current and next character
currentChar = line[charIndex];
nextChar = charIndex < line.Length - 1 ? line[charIndex + 1] : new Nullable <char>();
// Perform logic based on state and decide on next state
switch (currentState)
{
case ReadState.WaitingForNewField:
{
currentValue.Clear();
if (currentChar == DoubleQuote)
{
currentState = ReadState.PushingQuoted;
continue;
}
else if (currentChar == Comma)
{
values.Add(currentValue.ToString());
currentState = ReadState.WaitingForNewField;
continue;
}
else
{
currentValue.Append(currentChar);
currentState = ReadState.PushingNormal;
continue;
}
}
case ReadState.PushingNormal:
{
// Handle field content delimiter by comma
if (currentChar == Comma)
{
currentState = ReadState.WaitingForNewField;
values.Add(currentValue.ToString().Trim());
currentValue.Clear();
continue;
}
// Handle double quote escaping
if (currentChar == DoubleQuote && nextChar == DoubleQuote)
{
// advance 1 character now. The loop will advance one more.
currentValue.Append(currentChar);
charIndex++;
continue;
}
currentValue.Append(currentChar);
break;
}
case ReadState.PushingQuoted:
{
// Handle field content delimiter by ending double quotes
if (currentChar == DoubleQuote && nextChar != DoubleQuote)
{
currentState = ReadState.PushingNormal;
continue;
}
// Handle double quote escaping
if (currentChar == DoubleQuote && nextChar == DoubleQuote)
{
// advance 1 character now. The loop will advance one more.
currentValue.Append(currentChar);
charIndex++;
continue;
}
currentValue.Append(currentChar);
break;
}
}
}
// push anything that has not been pushed (flush)
values.Add(currentValue.ToString().Trim());
return(values);
}
public static CsvRecord[] GetRecords(string content, string delimiter)
{
List <CsvRecord> records = new List <CsvRecord>();
//List<string> fields = new List<string>();
content = content + "\n";
var charArray = content.ToArray();
//the following variables are used in the for loop.
var currentField = string.Empty;
var concatenating = true; //meaning we are concatenating a field. or to say, we find the start but we are not at the end of a field yet.
var startWithDoubleQuote = false;
var startRecord = true;
var currentRecord = new CsvRecord();
records.Add(currentRecord);
for (int i = 0; i < charArray.Length; i++)
{
var currentChar = charArray[i];
var nextChar = i + 1 < charArray.Length? charArray[i + 1] : '\0';
if (startRecord)
{
switch (currentChar)
{
case '\r':
continue;
case '\n':
continue;
case ',':
currentRecord.Add(string.Empty);
concatenating = false;
break;
case '"':
startWithDoubleQuote = true;
concatenating = true;
break;
default:
currentField += currentChar;
startWithDoubleQuote = false;
concatenating = true;
break;
}
startRecord = false;
}
else if (concatenating)
{
if (startWithDoubleQuote)
{
if (currentChar == '"')
{
//if this is the last char
if (i + 1 == charArray.Length)
{
currentField += currentChar;
AddField(currentRecord, ref currentField, ref concatenating);
continue;
}
if (nextChar == '"')
{
currentField += currentChar;
i++;
}
else //nextChar != '"'
{
AddField(currentRecord, ref currentField, ref concatenating);
if (nextChar == ',')
{
i++;
}
}
}
else // currentChar!='"'
{
if (i + 1 == charArray.Length)
{
throw new CsvFormatException();
}
currentField += currentChar;
}
}
else //not startWithDoubleQuote
{
//if this is the last char
if (i + 1 == charArray.Length)
{
currentField += currentChar;
currentField = currentField.Trim();
currentRecord.Add(currentField);
continue;
}
switch (currentChar)
{
case '\r':
case '\n':
currentRecord.Add(currentField);
currentRecord = new CsvRecord();
currentField = string.Empty;
records.Add(currentRecord);
startRecord = true;
continue;
case ',':
AddField(currentRecord, ref currentField, ref concatenating);
break;
default:
currentField += currentChar;
break;
}
}
}
else // not concatenating
{
switch (currentChar)
{
case '\r':
case '\n':
var previousChar = i > 0? charArray[i - 1]:'\0';
if (previousChar == ',')
{
currentRecord.Add(string.Empty);
currentRecord = new CsvRecord();
records.Add(currentRecord);
startRecord = true;
}
else
{
currentRecord = new CsvRecord();
records.Add(currentRecord);
startRecord = true;
}
continue;
case ',':
currentRecord.Add(string.Empty);
break;
case '"':
startWithDoubleQuote = true;
concatenating = true;
break;
default:
startWithDoubleQuote = false;
concatenating = true;
currentField += currentChar;
break;
}
}
}
//checked if the last record is empty
var last = records.Last();
var isEmpty = false;
if (last.Count == 0)
{
isEmpty = true;
}
else
{
foreach (string s in last)
{
if (string.IsNullOrEmpty(s))
{
isEmpty = true;
break;
}
}
}
if (isEmpty)
{
records.Remove(last);
}
return(records.ToArray());
}
private static void AddField(CsvRecord currentRecord, ref string currentField, ref bool concatenating)
{
currentRecord.Add(currentField.Trim());
currentField = string.Empty;
concatenating = false;
}
