PropertyHandler

This attribute enables property handling on a class property. When present, the library compiler automatically invokes the property handler’s Get() and Set() methods during serialization, deserialization, and hydration.

Given a customized IPropertyHandler implementation:

private class PersonAddressHandler : IPropertyHandler<string, Address>
{
    public Address Get(string input, PropertyHandlerGetOptions options)
    {
        return JsonConvert.Deserialize<Address>(input);
    }

    public string Set(Address input, PropertyHandlerSetOptions options)
    {
        return JsonConvert.Serialize(input);
    }
}

Apply this attribute to the property to use PersonAddressHandler during transformation.

public class Person
{
    public long Id { get; set; }
    public string Name { get; set; }
    [PropertyHandler(typeof(PersonAddressHandler))]
    public Address Address { get; set; }
}

When reading records, the Address property is populated with the deserialized value of the Address column.

using (var connection = new SqlConnection(connectionString))
{
    var person = connection.Query<Person>(10045);
    Console.WriteLine($"Name: {person.Name}, Address: {person.Address.Street}, {person.Address.Region}, {person.Address.Country} ({person.Address.ZipCode})")
}

In this example, the Address property maps to an NVARCHAR(MAX) column in [dbo].[Person]. When this attribute is present, the library skips automatic conversion from TypeMapper and enumerations.