Umbraco GetPropertyValueRecursively with custom logic to determine if a recursive value is valid

Readme.txt

The following code is intended for use as a replacement for the GetPropertyValue<T>(string alias, bool recursive) method when getting strongly typed values back.

This example uses Archetype (https://github.com/imulus/Archetype/tree/master/app/Umbraco/Umbraco.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 recursive) is trying to get a value recursively but accepts it.

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 TPropertyValue GetPropertyValueRecursively<TPropertyValue>(this IPublishedContent content, string alias, Expression<Func<TPropertyValue, bool>> recursiveValueIsValidExpression, TPropertyValue defaultValue = default(TPropertyValue)) {
            if (content.HasProperty(alias)) {
                var value = content.GetPropertyValue<TPropertyValue>(alias);

                if (recursiveValueIsValidExpression.Compile().Invoke(value)) {
                    return value;
                }
            }

            if (content.Parent != null) {
                return content.Parent.GetPropertyValueRecursively(alias, recursiveValueIsValidExpression);
            }

            return defaultValue;
        }
    }
}

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.GetPropertyValueRecursively<ArchetypeModel>("archetypeBuiltProperty", x => x.Fieldsets.Any());

            var viewModel = new {
                MyValue = propertyGotRecursively
            };

            return View(viewModel);
        }
    }
}

So it walks up the tree until a content has the property with the proper alias, and a value satisfying the "is valid" method, correct?
Question: why use an Expression<Func> and compile it? And not directly a Func? Not sure there's a benefit, and here you're re-compiling the expression on each content.

Yeah you don't want to be compiling every time.

Can you post a sample of the ArchetypeModel?

@jamiepollock - I think it is a good and very useful extension method.

I did a fork and made some modifications:

• Made it an overload of the existing GetPropertyValue<T>.
• Replaced the Expression with a Func, (as noted by @zpqrtbnk)
• Included the defaultValue in the call to the parent content node.

https://gist.github.com/leekelleher/8e85a1020179edfad29a

Feel free to do what you want with it.