Dynamic Sort expression issue - sorting

Question

Let say I have classes hierarchy like
public class A
{
public int AMember { get; set; }
}
public class B
{
public int BMember { get; set; }
public virtual A AasMember { get; set; }
}
public static class OrderByUtility
{
public static bool PropertyExists<T>(string propertyName)
{
return typeof(T).GetProperty(propertyName, BindingFlags.IgnoreCase |
BindingFlags.Public) != null;
}
}
From main class whenever I use this Utility
OrderByUtility.PropertyExists BClass>("BMember");
This works fine and returns TRUE. But whenever I use
OrderByUtility.PropertyExists BClass> ("AMember"); returns False
I want same PropertyExist function work for all Composed Object. Please suggest resolving this issue. Thanks

Answer 1

Here is a really naive implementation of it. You could make it recursive to keep checking nested types. It also keeps a cache so it doesn't do the expensive processing on each lookup.
public class A
{
public int AMember { get; set; }
}
public class B
{
public int BMember { get; set; }
public virtual A AasMember { get; set; }
}
public static class OrderByUtility
{
private static readonly Dictionary<Type, Dictionary<string, bool>> Seen =
new Dictionary<Type, Dictionary<string, bool>>();
public static bool PropertyExists<T>(string propertyName)
{
var type = typeof(T);
if (!Seen.TryGetValue(type, out var props))
{
props = new Dictionary<string, bool>();
Seen[type] = props;
}
if (props.ContainsKey(propertyName))
{
return props[propertyName];
}
var prop = GetPropertyByName(type, propertyName);
if (prop == null)
{
foreach (var p in type.GetProperties())
{
var propType = p.PropertyType;
if (!propType.IsClass && !propType.IsInterface) continue;
prop = GetPropertyByName(propType, propertyName);
if (prop != null)
{
break;
}
}
}
props[propertyName] = prop != null;
return props[propertyName];
}
private static PropertyInfo GetPropertyByName(Type t, string name)
{
return t.GetProperty(name, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance);
}
}
Usage:
bool exists = OrderByUtility.PropertyExists<B>("AMember");