using System;

using Newtonsoft.Json;

using System.Linq;

using System.Collections.Generic;

using System.Dynamic;

public class Program

{

    public static void Main()

    {

        Test t = new Test();

        // create and serialise object

        var listing = t.CreateListingObject();

        var serialisedListing = JsonConvert.SerializeObject(listing);

        // deserialise and flatten object

        var deserialisedListing = JsonConvert.DeserializeObject<Listing>(serialisedListing);

        dynamic flattenedListing = t.FlattenObject(deserialisedListing);

        foreach(var item in flattenedListing) {

            Console.WriteLine(item);

        }

    }

}

​

public class Test {

​

    public Test () {}

    public Listing CreateListingObject() {

        var descriptors = new List<Descriptor>();

        var colourDescriptor = new Descriptor {

            Name = "Colour",

            Value = "Red",

            SearchableValue = "Red"

        };

        var sizeDescriptor = new Descriptor {

            Name = "Size",

            Value = "Large",

            SearchableValue = "Large"

        };

        descriptors.Add(colourDescriptor);

        descriptors.Add(sizeDescriptor);

        return new Listing {

            Id = 123,

            Title = "Something",

            Descriptors = descriptors

        };

    }

    public dynamic FlattenObject(Listing listing) {

        dynamic flattenedListing = new ExpandoObject();

        flattenedListing.Id = listing.Id;

        flattenedListing.Title = listing.Title;

        foreach (Descriptor descriptor in listing.Descriptors) {

            var formattedDescriptor = new ExpandoObject();

            var descriptorName = descriptor.Name.ToLower();

            AddProperty(flattenedListing, "d_k_" + descriptorName, descriptor.Value);

            AddProperty(flattenedListing, "d_t_"+ descriptorName +"_searchable_value", descriptor.SearchableValue);

        }

        return flattenedListing;

    }

    public void AddProperty(ExpandoObject expando, string propertyName, object propertyValue)

    {

        var expandoAsDictionary = expando as IDictionary<string, object>;

        if (expandoAsDictionary.ContainsKey(propertyName)) {

            expandoAsDictionary[propertyName] = propertyValue;  

        }

        else {

            expandoAsDictionary.Add(propertyName, propertyValue);

        }

    }

}

​

public class Listing {

    public long Id { get; set; }

    public string Title { get; set; }

    public IEnumerable<Descriptor> Descriptors { get; set; }

}

​

public class Descriptor {

    public string Name { get; set; }

    public string Value { get; set; }

    public string SearchableValue { get; set; }

}