A simple data resolver for the Umbraco Similarity package

SimilarityDataResolver.cs

using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Umbraco.Courier.Core;
using Umbraco.Courier.Core.Logging;
using Umbraco.Courier.DataResolvers;
using Umbraco.Courier.ItemProviders;
using System.Collections.Generic;

namespace Project.BusinessLogic.Data_Resolvers
{
    public class SimilarityDataResolver : PropertyDataResolverProvider
    {
        public override string EditorAlias
        {
            get
            {
                return "Similarity";
            }
        }

        private enum Direction
        {
            Extracting,
            Packaging
        }

        public override void PackagingProperty(Item item, ContentProperty propertyData)
        {
            UpdateContentIdentifiers(item, propertyData, Direction.Packaging);
        }

        public override void ExtractingProperty(Item item, ContentProperty propertyData)
        {
            UpdateContentIdentifiers(item, propertyData, Direction.Extracting);
        }

        private void UpdateContentIdentifiers(Item item, ContentProperty propertyData, Direction direction)
        {
            if (propertyData.Value == null) return;
            var contentIds = propertyData.Value.ToString().Split(',');
            var newIds = new List<string>();
            foreach (var contentId in contentIds)
            {
                string contentIdentifier = null;
                switch (direction)
                {
                    case Direction.Packaging:
                        contentIdentifier = ExecutionContext.DatabasePersistence.GetUniqueId(int.Parse(contentId), UmbracoNodeObjectTypeIds.Document).ToString();
                        item.Dependencies.Add(contentIdentifier, ItemProviderIds.documentItemProviderGuid);
                        break;
                    case Direction.Extracting:
                        contentIdentifier = ExecutionContext.DatabasePersistence.GetNodeId(Guid.Parse(contentId), UmbracoNodeObjectTypeIds.Document).ToString();
                        break;
                }
                newIds.Add(contentIdentifier);
            }
            propertyData.Value = String.Join(",", newIds);
        }


    }

}