Column Name Convention

Question

I want to specify a column name convention that basically takes a pascal cased field and converts it to all uppercase with underscores. So property OrderId becomes column "ORDER_ID". I also want this convention to be applied only if I don't already specify one in the mapping. So far I have the skeleton below:

public class PascalCaseColumnNameConvention : IPropertyConvention
{
    public bool Accept(IPropertyInstance instance)
    {
        //Not sure what I should have here
    }
    public void Apply(IPropertyInstance instance)
    {
        instance.Column(instance.Property.Name.ChangePascalCaseToUnderscore());
    }
}

Also is there a better way of channging the case besides an string extension method? Any libraries that already do this sort of thing?

Answer 1

In Accept method in this case you should just return true. This method is to decide whether your convention should apply for a given instance, for example you might want to change the default name only for your int-typed fields etc. If you're defining a general convention, true means just "accept all instances". It can be still overriden by specyfying the column name in the mapping, though.

About changing the case - I don't know such a library, either. But the task is quite simple, so your solution seems very reasonable here.

EDIT

Well, what FNH version are you using? I can't see IPropertyConvention to have bool Accept method.

What you can do here is to implement both IPropertyConvention (with void Apply only) and IPropertyConventionAcceptance (with Accept method working a bit differently). Try something like that (haven't tested):

public class PascalCaseColumnNameConvention : IPropertyConvention, IPropertyConventionAcceptance
{
    public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria)
    {
        criteria.Expect(x => !x.Columns.HasUserDefined());
    }

    public void Apply(IPropertyInstance instance)
    {
        instance.Column(instance.Property.Name.ChangePascalCaseToUnderscore());
    }
}

I've also found a neat class doing lot of useful string conversions - see Inflector. But anyway, if you need only this particular conversion, I would stay with own simple solution.