1-README.md

The following code is intended for use as an overloaded extension for the GetPropertyValue<T>(string alias, bool recurse) method when getting strongly typed values back.

This example uses Archetype where in Umbraco v7.1.8 calling such a property value recursively returns an ArchetypeModel with 0 fieldsets.

There could be other possible applications for allowing a developer to determine the logic when GetPropertyValue<T>(string alias, bool recurse) is trying to get a value recursively but accepts it.

2-MyPageController.cs

using Archetype.Models;
using My.Website.ExtensionMethods;
using System.Linq;
using System.Web.Mvc;
using Umbraco.Web.Models;
using Umbraco.Web.Mvc;

namespace My.Website.Controllers
{
	public class MyPageController : RenderMvcController
	{
		public override ActionResult Index(RenderModel model)
		{
			var propertyGotRecursively = model.Content
				.GetPropertyValue<ArchetypeModel>("archetypeBuiltProperty", true, x => x.Fieldsets.Any());

			var viewModel = new
			{
				MyValue = propertyGotRecursively
			};

			return View(viewModel);
		}
	}
}

3-ExtensionMethods.cs

using System;
using System.Linq.Expressions;
using Umbraco.Core.Models;
using Umbraco.Web;

namespace My.Website.ExtensionMethods
{
	public static class UmbracoExtensions
	{
		public static T GetPropertyValue<T>(this IPublishedContent content, string alias, bool recurse, Func<T, bool> isValid, T defaultValue = default(T))
		{
			if (content.HasProperty(alias))
			{
				var value = content.GetPropertyValue<T>(alias);

				if (isValid(value))
				{
					return value;
				}
			}

			if (content.Parent != null)
			{
				return content.Parent.GetPropertyValue(alias, true, isValid);
			}

			return defaultValue;
		}
	}
}