Proxoft.ValueObjects 1.1.0

Value objects

What is and why should you use a value object: https://learn.microsoft.com/en-us/dotnet/architecture/microservices/microservice-ddd-cqrs-patterns/implement-value-objects

The library contains some base implementations of Int, String, NullableString, Decimal and Double value objects.

Usage

public class FooId: IntValueObject<FooId>
{
  public static readonly FooId None = new(0);
  
  public class FooId(int value) : base(value, minValue: 0)
  {
  }
  
  public FooId Next()
  {
    return new FooId(this + 1);
  }
}

public class Lat : DecimalValueObject<Lat>
{
    public static readonly Lat Undefined = new(-100); // whatever value outside of the range

    public Lat(decimal value) : base(
        value,
        Guard)
    {
    }

    private static void Guard(decimal value)
    {
        if(value == -100)
        {
            return;
        }

        GuardFunctions.ThrowIfNotInRange(value, -90m, 90m);
    }
}

For System.Text.Json use JsonConverters:

public class Foo(int value) : IntValueObject<Foo>(value, minValue: 5)
{
}

JsonSerializerOptions _options = new()
{
    Converters = {
        new IntValueObjectConverter<Foo>()
    }
};

// later in code
Foo f = new(15);
string json = JsonSerializer.Serialize(f, _options);
// json is "15"

Foo? deserialized = JsonSerializer.Deserialize<Foo>("25", _options);
// deserialized == new Foo(25)

of a generic approach

public class Foo(int value) : IntValueObject<Foo>(value, minValue: 5)
{
}

JsonSerializerOptions _options = new()
{
    Converters = {
        new DefaultValueObjectJsonConverter()
    }
};

// later in code
Foo f = new(15);
string json = JsonSerializer.Serialize(f, _options);
// json is "15"

Foo? deserialized = JsonSerializer.Deserialize<Foo>("25", _options);
// deserialized == new Foo(25)