Question

I have this class:

public class MyEntity
{
    public virtual int Id { get; set; }
    public virtual IList<Point> Vectors { get; set; }
}

How can I map the Vectors in Fluent NHibernate to a single column (as value)? I was thinking of this:

public class Vectors : ISerializable
{
    public IList<Point> Vectors { get; set; }

    /* Here goes ISerializable implementation */
}

public class MyEntity
{
    public virtual int Id { get; set; }
    public virtual Vectors Vectors { get; set; }
}

Is it possible to map the Vectors like this, hoping that Fluent NHibernate will initialize Vectors class as standard ISerializable?

Or how else could I map IList<Point> to a single column? I guess I will have to write the serialization/deserialization routines myself, which is not a problem, I just need to tell FNH to use those routines.

I guess I should use IUserType or ICompositeUserType, but I have no idea how to implement them, and how to tell FNH to cooperate.

Answer 1

Found an answer. 🙂

Heading UserTypeConvention<T> at:
http://wiki.fluentnhibernate.org/Available_conventions
for custom type conversions.

This is for implementing custom type convertors:
http://intellect.dk/post/Implementing-custom-types-in-nHibernate.aspx

Additional related links I’ve found:
http://www.lostechies.com/blogs/rhouston/archive/2008/03/23/mapping-strings-to-booleans-using-nhibernate-s-iusertype.aspx
http://www.martinwilley.com/net/code/nhibernate/usertype.html
Link
http://kozmic.pl/archive/2009/10/12/mapping-different-types-with-nhibernate-iusertype.aspx
Link

UserTypeConvention<T> usage:
http://jagregory.com/writings/fluent-nhibernate-auto-mapping-type-conventions/

The most important code in last link is this:

public class ReplenishmentDayTypeConvention : ITypeConvention
{
  public bool CanHandle(Type type)
  {
    return type == typeof(ReplenishmentDay);
  }

  public void AlterMap(IProperty propertyMapping)
  {
    propertyMapping
      .CustomTypeIs<ReplenishmentDayUserType>()
      .TheColumnNameIs("RepOn");
  }
}

Where ReplenishmentDayUserType is IUserType-derived class and ReplenishmentDay is the class, which should be converted using your user type converter.

And this:

autoMappings
  .WithConvention(convention =>
  {
    convention.AddTypeConvention(new ReplenishmentDayTypeConvention());
    // other conventions
  });