write a space delimited file with csvhelper

Question

I did not see this option in CsvHelper, but does this library support space delimiters such that there is a predetermined number of characters like spaces or periods for each field?

example: firstname -len:10 lastname - len:15 would translate to this with periods

john......doe............
sam.......simpson........

Answer 1

CsvHelper doesn't currently support fixed width files. There is an open feature request to add fixed width support, but I don't think there are any plans to implement it anytime soon. https://github.com/CsvHelperContrib/CsvHelperContrib/issues/2

If you are writing a fixed width file, this should work. I don't have a way to read a fixed width file.

public class Program
{
    public static void Main(string[] args)
    {     
        var records = new List<Foo>
        {
            new Foo { FirstName = "john", LastName = "doe" },
            new Foo { FirstName = "sam", LastName = "simpson"}
        };

        using (CsvWriter csv = new CsvWriter(Console.Out))
        {
            csv.Configuration.RegisterClassMap<FooMap>();
            csv.Configuration.HasHeaderRecord = false;
            csv.Configuration.Delimiter = "";
            csv.Configuration.ShouldQuote = (field, context) => false;
            csv.WriteRecords(records);
        }

        Console.ReadLine();
    }
}

public class Foo
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public sealed class FooMap : ClassMap<Foo>
{
    public FooMap()
    {
        Map(m => m.FirstName).TypeConverter(new FixedWidthOutput(10, '.'));
        Map(m => m.LastName).TypeConverter(new FixedWidthOutput(15, '.'));
    }
}

public class FixedWidthOutput : DefaultTypeConverter
{
    private readonly int _fieldLength;
    private readonly char _paddingCharacter;

    public FixedWidthOutput(int fieldLength, char paddingCharacter = ' ')
    {
        _fieldLength = fieldLength;
        _paddingCharacter = paddingCharacter;
    }

    public override string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
    {
        return value.ToString().PadRight(_fieldLength, _paddingCharacter);
    }
}