Custom Converter

Explains how to extend the library with a new converter

For fixed length records where you need to read decimal data and you don't have an explicit decimal dot (because this isn't required or a Cobol layout). You read it with a customer converter.

If you want to parse a file with a field that has different parsing rules you can define a CustomConverter.For example, if you have the following source file:

Input.txt

0001250001458800013025
0001260012345600234567
0001270123456702345678
0001280087654300123456

RecordClass.cs

[FixedLengthRecord]
public class PriceRecord
{
    [FieldFixedLength(6)]
    public int ProductId;

    [FieldFixedLength(8)]
    [FieldConverter(typeof(MoneyConverter))]
    public decimal PriceList;

    [FieldFixedLength(8)]
    [FieldConverter(typeof(MoneyConverter))]
    public decimal PriceEach;
}

The last step is to define the converter, you must inherit from ConverterBase:

MoneyConverter.cs

public class MoneyConverter : ConverterBase
{
    public override object StringToField(string from)
    {
        return Convert.ToDecimal(Decimal.Parse(from) / 100);
    }

    public override string FieldToString(object fieldValue)
    {
        return ((decimal)fieldValue).ToString("#.##").Replace(".", "");
    }

}

Done !! You actually parse the file with:

RunEngine.cs

var engine = new FileHelperEngine<PriceRecord>();

var res = engine.ReadFile("Input.txt");

foreach (var product in res)
    Console.WriteLine("Product {0} price {1}", product.ProductId, product.PriceList);

Console

Product 125 price 145,88
Product 126 price 1234,56
Product 127 price 12345,67
Product 128 price 8765,43