Nested property in Expression tree

Question

I want to write an expression that will retrieve a property within a property. My 2 classes:

public class BusinessType
{
    public string Proprietor
    {
        get { return "Proprietor"; }
    }
}

public class VendorApplicationViewModel
{
    public List<BusinessType> BusinessClassification { get; set; }
}

public static IHtmlString RadioListForIEnum<TModel, TProperty>(this HtmlHelper<TModel> htmlhelper, 
                                                               Expression<Func<TModel, TProperty>> expression)
{
    var prop = ModelMetadata.FromLambdaExpression(expression, htmlhelper.ViewData);
    //Func<TModel2, TProperty2> nestedProperty = 
    return null;
}

I'm rather lost as to how I can achieve this. Also I'm fairly new to expression trees any good recommendations on tutorials and the likes would be greatly appreciated. Thanks

Its extremely difficult to decipher what you're asking here. — nawfal, Jun 02 '13 at 15:52

score 1 · Answer 1 · answered Jul 15 '13 at 16:42

I think you're simply trying to get a property within a property.

You could have the following.

 Expression<Func<VendorApplicationViewModel, string>> lambda1 = model => model.BusinessClassification[0].Proprietor;

which can be recreated in code as

 ParameterExpression param = Expression.Parameter(typeof(VendorApplicationViewModel));
 Expression<Func<VendorApplicationViewModel, string>> lambda2 = Expression.Lambda<>(
      Expression.Property(
           Expression.Property(
                param,
                "BusinessClassification",
                Expression.Constant(0)
           ),
           "Proprietor"
      ),
      param
 );

Nested property in Expression tree

1 Answers1