PropertyDataDataSource.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using Umbraco.Community.Contentment.DataEditors;
using Umbraco.Core.PropertyEditors;
using Umbraco.Web;

namespace MyWebsite.DataSources
{
    public class PropertyDataDataSource : IDataListSource
    {
        public string Name => "Umbraco Property Data";

        public string Description => "Data source for umbraco property data coming from the website root node.";

        public string Icon => "icon-globe";

        public OverlaySize OverlaySize => OverlaySize.Small;

        public Dictionary<string, object> DefaultValues => new Dictionary<string, object>();

        public IEnumerable<ConfigurationField> Fields => new ConfigurationField[]
        {
            new ConfigurationField
            {
                Key = "propAlias",
                Name = "Property alias",
                Description = "The property alias",
                View = "textstring"
            }
        };

        public IEnumerable<DataListItem> GetItems(Dictionary<string, object> config)
        {

            var items = new List<DataListItem>();

            using (UmbracoContextReference umbracoContextReference = DependencyResolver.Current.GetService<IUmbracoContextFactory>().EnsureUmbracoContext())
            {

                var content = umbracoContextReference.UmbracoContext.Content.GetAtRoot().First();

                var propertyAlias = config["propAlias"].ToString();


                var prop = content.GetProperty(propertyAlias);
                if (prop == null)
                    throw new NullReferenceException("Property not found on node");


                foreach (var value in content.GetProperty(propertyAlias).GetValue() as String[])
                {
                    items.Add(new DataListItem
                    {
                        Name = value,
                        Value = value
                    });
                }
            }


            return items;
        }
    }
}