Is it possible to enforce a max length on a string with a mapping?

[R1Fo]

Hi,

I'm importing a string into a SQL table with a max length of 50. Is it possible to enforce a max length on a string value in one column with a mapping? If the string being imported is longer than 50 characters I would want to import the first 50 characters.

[JoshClose]

No. You could write a custom converter to do it though.

public class TruncateStringConverter : StringConverter
{
	public override object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
	{
		var s = base.ConvertFromString(text, row, memberMapData) as string;
		return s == null ? s : s.Substring(0, 50);
	}
}

You can apply that via a mapping like

Map(m => m.StringProperty).TypeConverter<TruncateStringConverter>();

Or globally for all strings like

csv.Context.TypeConverterCache.AddConverter<string>(new TruncateStringConverter());

[R1Fo]

Thanks for the advice.

For anyone else who might read this I tweaked the convert method slightly because the string doesn't always exceed 50 characters.

    public override object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
   {
      var s = base.ConvertFromString(text, row, memberMapData) as string;
      if (string.IsNullOrEmpty(s)) return s;
      return s.Length <= 50 ? s : s.Substring(0, 50);
   }