Deserialize json with auto-trimming strings

Question

I use Newtonsoft.Json library

Is there a way to trim spaces from any string data during deserialization?

class Program
{
    class Person
    {
              


        

Answer 1

The solution provide above didnt work for me. I modified Sam Fisher solution and combined it with Timmerz solution. how to get both fields and properties in single call via reflection?

public sealed class TrimAttribute : Attribute {
}

public static class TrimConverterExtension {
  public static void SetValue(this MemberInfo member, object property, object value) {
     switch (member.MemberType) {
        case MemberTypes.Property:
           ((PropertyInfo)member).SetValue(property, value, null);
           break;
        case MemberTypes.Field:
           ((FieldInfo)member).SetValue(property, value);
           break;
        default:
           throw new Exception("Property must be of type FieldInfo or PropertyInfo");
     }
  }

  public static object GetValue(this MemberInfo member, object property) {
     switch (member.MemberType) {
        case MemberTypes.Property:
           return ((PropertyInfo)member).GetValue(property, null);
        case MemberTypes.Field:
           return ((FieldInfo)member).GetValue(property);
        default:
           throw new Exception("Property must be of type FieldInfo or PropertyInfo");
     }
  }

  public static Type GetMemberType(this MemberInfo member) {
     switch (member.MemberType) {
        case MemberTypes.Field:
           return ((FieldInfo)member).FieldType;
        case MemberTypes.Property:
           return ((PropertyInfo)member).PropertyType;
        case MemberTypes.Event:
           return ((EventInfo)member).EventHandlerType;
        default:
           throw new ArgumentException("MemberInfo must be if type FieldInfo, PropertyInfo or EventInfo", "member");
     }
  }
}

public class TrimConverter : JsonConverter where T : new() {
  public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) {
  }

  public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) {
     var jObject = JObject.Load(reader);
     var obj = new T();
     serializer.Populate(jObject.CreateReader(), obj);

     //Looks for the trim attribute on the property
     const BindingFlags bindingFlags = BindingFlags.Public | BindingFlags.Instance;
     IEnumerable members = objectType.GetFields(bindingFlags).Cast()
         .Concat(objectType.GetProperties(bindingFlags))
         .Where(p => p.GetMemberType() == typeof(string))
         .Where(p => Attribute.GetCustomAttributes(p).Any(u => (Type)u.TypeId == typeof(TrimAttribute)))

         .ToArray();

     foreach (var fieldInfo in members) {
        var val = (string)fieldInfo.GetValue(obj);
        if (!string.IsNullOrEmpty(val)) {
           fieldInfo.SetValue(obj, val.Trim());
        }
     }

     return obj;
  }

  public override bool CanConvert(Type objectType) {
     return objectType.IsAssignableFrom(typeof(T));
  }
}