Add dummy empty fields in CSVHelper

Question

I use the library CsvHelper to write CSV. I have object which doesn't contain all the records and I have to add empty fields to my CSV. For instance:

public class Example
{
   public string Test1 { get; set; }
   public string Test2 { get; set; }
}

with this map:

public class ExampleMap : ClassMap<Example>
{
    public ExampleMap()
    {
      Map(ex=>ex.Test1).Index(0);
      Map(ex=>ex.Test2).Index(4);
    }
}

and i'd like to have for this object

new Example() { Test1="dummy", Test2="field" };

this csv result:

dummy;;;field

I really struggle with this problem, if someone can help me :) Many thanks

Answer 1

Note: This might be superseded by the Constant() operator in newer versions.

A more API-consistent approach might be to use a custom ITypeConverter. Here is how I use it:

Map(i => i.SomeUnusedId).Name("SomeId").TypeConverter<EmptyConverter>(); //converst to an empty string

Then the converter might look like this:

public class EmptyConverter : ITypeConverter {
    /// <inheritdoc />
    public bool CanConvertFrom(Type type) {
        return true;
    }

    /// <inheritdoc />
    public bool CanConvertTo(Type type) {
        return true;
    }

    /// <inheritdoc />
    public object ConvertFromString(TypeConverterOptions options, string text) {
        return string.Empty;
    }

    /// <inheritdoc />
    public string ConvertToString(TypeConverterOptions options, object value) {
        return string.Empty;
    }
}