How can I get the sitecore field from an object property, mapped by glassmapper?

Question

We are using Glass Mapper with Sitecore, with our models we can get the values of sitecore fields. But I want to easily get the sitecore fields(sitecore field type) by using the model without hardcoding any strings (when using GetProperty(), you need the property name string ) into the method.

So I wrote this thing to achieve this, however I am not happy with 2 types need to be passed in when using it since it looks awful when you have a long model identifier.

   public static string SitecoreFieldName<T, TU>(Expression<Func<TU>> expr)
    {
         var body = ((MemberExpression)expr.Body);
         var attribute = (typeof(T).GetProperty(body.Member.Name).GetCustomAttributes(typeof(SitecoreFieldAttribute), false)[0]) as SitecoreFieldAttribute;
         return attribute.FieldName;
    }

The most ideal way is be able to get it like this Model.SomeProperty.SitecoreField(). However I can't figure out how to do the refection from there. Because that can will be a extension for any type.

Thanks!

Answer 1

public static string SitecoreFieldName<TModel>(Expression<Func<TModel, object>> field)
{
    var body = field.Body as MemberExpression;

    if (body == null)
    {
        return null;
    }

    var attribute = typeof(TModel).GetProperty(body.Member.Name)
        .GetCustomAttributes(typeof(SitecoreFieldAttribute), true)
        .FirstOrDefault() as SitecoreFieldAttribute;

    return attribute != null
        ? attribute.FieldName
        : null;
}

Note that I put inherit=true on the GetCustomAttributes method call.
Otherwise inherited attributes are ignored.