Fluent NHibernate conventions II – example for enumerations

Most of the time I do not have to touch Fluent NHibernate conventions I have created some time ago. But from time to time I find in mappings some common scenario which is a good candidate to become a convention. This time I found that every time I am mapping a property of enumeration type I have to specify its length manually.

Because I hate redundant work I have defined a Fluent NHibernate convention presented below.

using System;
using System.Linq;
using FluentNHibernate.Conventions;
using FluentNHibernate.Conventions.AcceptanceCriteria;
using FluentNHibernate.Conventions.Inspections;
using FluentNHibernate.Conventions.Instances;

namespace ExampleConventions
{
    public class EnumColumnLengthConvention
        : IPropertyConvention, IPropertyConventionAcceptance
    {
        public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria)
        {
            criteria.Expect(x => x.Property.PropertyType.IsEnum)
                .Expect(x => x.Length == 0);
        }

        public void Apply(IPropertyInstance instance)
        {
            var names = Enum.GetNames(instance.Property.PropertyType);
            instance.Length(names.Max(name => name.Length));
        }
    }
}

The convention is really simple. Its whole logic can be found in Apply method and I think it is self explanatory so there is nothing to describe here.