Fluent NHibernte Alterations / Conventions

Question

I like the pattern I saw in this blog post (http://marekblotny.blogspot.com/2009/04/conventions-after-rewrite.html), where the author is checking to see if a table name alteration has already been made before applying a convention.

public bool Accept(IClassMap target)
{
    //apply this convention if table wasn't specified with WithTable(..) method
    return string.IsNullOrEmpty(target.TableName);
}

The convention interface I'm using for a string length is IProperty:

public class DefaultStringLengthConvention: IPropertyConvention
{
    public bool Accept(IProperty property) {
        //apply if the string length hasn't been already been specified
        return ??; <------ ??
    }

    public void Apply(IProperty property) {
        property.WithLengthOf(50);
    }
}

I don't see where IProperty exposes anything that tells me if the property has already been set. Is this possible?

TIA, Berryl

Answer 1

To clarify in code what Stuart and Jamie are saying, here's what works:

public class UserMap : IAutoMappingOverride<User>
{
    public void Override(AutoMap<User> mapping) {
        ...
        const int emailStringLength = 30;
        mapping.Map(x => x.Email)
            .WithLengthOf(emailStringLength)                        // actually set it
            .SetAttribute("length", emailStringLength.ToString());  // flag it is set
        ...

    }
}

public class DefaultStringLengthConvention: IPropertyConvention
{
    public bool Accept(IProperty property) {
        return true;
    }

    public void Apply(IProperty property) {
        // only for strings
        if (!property.PropertyType.Equals(typeof(string))) return;

        // only if not already set
        if (property.HasAttribute("length")) return;

        property.WithLengthOf(50);
    }
}