How to replace chars/symbols in a process of writing of csv string/file with CsvHelper? - export-to-csv

Question

I need to get rid of some symbols from each column in a row in a process of writing of csv string but I can't find such feature in CsvHelper.CsvWriter.Configuration nor CsvHelper.CsvWriter.Context or somewhere else.
As an acceptable for me workaround I tried to override method ConvertUsing of class MemberMap<TClass, TMember> and it didn't work correctly:
public class CustomMemberMap < TClass, TMember >: MemberMap < TClass, TMember > {
public CustomMemberMap(MemberInfo member): base(member) {}
public override MemberMap < TClass, TMember > ConvertUsing(Func < TClass, string > convertExpression) => base.ConvertUsing(row => convertExpression(row).Replace("\r", "").Replace("\n", ""));
}
public class CustomClassMap < TClass >: ClassMap < TClass > where TClass: new() {
public override MemberMap < TClass, TMember > Map < TMember > (Expression < Func < TClass, TMember >> expression, bool useExistingMap = true) => new CustomMemberMap < TClass, TMember > (base.Map(expression, useExistingMap).Data.Member);
}
public sealed class CsvFileMapperAccommodation: CustomClassMap < Accommodation > {
public CsvFileMapperAccommodation() {
Map(m => m.Name).Name($ "AccommodationName").ConvertUsing(x => $ "{x.Name}");
Map(m => m.ExternalKey).Name($ "AccommodationExternalKey").ConvertUsing(x => $ "{x.ExternalKey}");
Map(m => m.Pension).Name($ "AccommodationPension").ConvertUsing(x => $ "{x.Pension}");
Map(m => m.Category).Name($ "AccommodationCategory").ConvertUsing(x => $ "{x.Category}");
Map(m => m.BuyingPrice).Name($ "AccommodationBuyingPrice").ConvertUsing(x => $ "{x.BuyingPrice}");
Map(m => m.Margin).Name($ "AccommodationMargin").ConvertUsing(x => $ "{x.Margin}");
Map(m => m.Price).Name($ "AccommodationPrice").ConvertUsing(x => $ "{x.Price}");
Map(m => m.Quantity).Name($ "AccommodationQuantity").ConvertUsing(x => $ "{x.Quantity}");
Map(m => m.Supplier).Name($ "AccommodationSupplier").ConvertUsing(x => $ "{x.Supplier}");
}
}
The object (which I try to map) contains a lot of properties so in an output I have about 300 fields per row, therefore, it's too complicated and not elegant to change manually the object data in the beginning and the value for each of the fields in the end. So I only try to map this object into a csv string hoping that it's possible to change it on the fly.

Answer 1

I think creating a custom StringConverter might meet your needs.
public class Program
{
public static void Main(string[] args)
{
var records = new List<Foo>()
{
new Foo {Property1 = "Property 1 with \r\n \\r\\n", Property2 = "Property2 with \n \\n"}
};
using (var csv = new CsvWriter(Console.Out, CultureInfo.InvariantCulture))
{
csv.Configuration.TypeConverterCache.AddConverter<string>(new FooStringConverter());
csv.WriteRecords(records);
}
Console.ReadKey();
}
}
public class Foo
{
public string Property1 { get; set; }
public string Property2 { get; set; }
}
public class FooStringConverter: StringConverter
{
public override string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
{
var stringValue = (string)value;
if (stringValue != null)
{
stringValue = stringValue.Replace("\r", "").Replace("\n", "");
}
return base.ConvertToString(stringValue, row, memberMapData);
}
}