Question

I have an existing NHibernate application that was created in .NET 2, it’s a WinForms app that has a separate DLL compiled for the data classes & all the hbm.xml files.

What I want to do now is show on the form which fields are not nullable, by changing the border to red.

Problem is I can’t seem to find anywhere where I can cycle through the bound fields (that I can do) on the form, and read the not-null=”false” (or true) parameter.

Any thoughts?

I am open to Fluent NHibernate, however this is a VB.NET app, and I am a Fluent Nhibernate noob 🙂

Also open to other ways of doing this, as long as I can make them fit into the app reasonably well 🙂

Thanks!

Answer 1

You don’t need to read the hbm.XML files directory as the SessionFactory contains MetaData regarding all mapped entities. One way to find all meta data for a entity is as follows;

After the SessionFactory has been built:-

var metaData = SessionFactory.GetClassMetadata(typeof(Model.Entities.Client));
for (int i = 0; i < metaData.PropertyNames.Length -1; i++)
{
    System.Diagnostics.Debug.Print(metaData.PropertyNames[i]);
    System.Diagnostics.Debug.Print(metaData.PropertyNullability[i].ToString());
}

In my case I get the following:-

Name
False
Address1
False
Address2
True
...
Postcode
True

Remember FALSE means NOT-NULL that is the property expects an entry

Another way is to add DataAnnotations to your model properties.

[Required(ErrorMessage = "You must supply a postcode")]
public virtual string Postcode { get; set; }

There are good articles on the internet to show you how to use this in a winforms project.