Ditto - Example of mapping an Archetype property to custom POCO model/type

1-README.md

Here is an example of using Ditto to map an Archetype property to custom POCO model/type.

---

Let's say that we have an Archetype to represent some SEO meta-data, and we'll call the DocType property "metaData".

We'd have 3 properties in the Archetype:

• metaTitle
• metaDescription
• metaKeywords

Then for our MyPoco POCO that we'd like to map to our content-node (DocumentType), we would have a property called MetaData (of a custom class/type also called MetaData).

Special note: On the custom class/type MetaData, we used the TypeConverter attribute to declare the custom converter. This means that whenever Umbraco's .GetPropertyValue<T> is called, the associated TypeConverter will be used.

So when Ditto attempts to map the "metaData" DocType property with the POCO's MetaData property - the MetaDataTypeConverter will be called.

Important note: Because Archetype comes with its own custom ValueConverter, the value type that is passed into our MetaDataTypeConverter will be of type ArchetypeModel (as opposed to a JSON string).

From there, our custom converter can use the ArchetypeModel to access its fieldsets and nested property values - see the ConvertFromArchetype method.

2-MyPoco.cs

namespace Our.Umbraco.Ditto.ArchetypeExamine
{
	public class MyPoco
	{
		//
		// other properties go here
		//
	  
		public MetaData MetaData { get; set; }
	}
}

3-MetaData.cs

using System.ComponentModel;

namespace Our.Umbraco.Ditto.ArchetypeExamine
{
	[TypeConverter(typeof(MetaDataTypeConverter))]
	public class MetaData
	{
		public string Description { get; set; }

		public string Keywords { get; set; }

		public string Title { get; set; }
	}
}

4-MetaDataTypeConverter.cs

using System;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using Archetype.Models;
using Umbraco.Core;

namespace Our.Umbraco.Ditto.ArchetypeExamine
{
	public class MetaDataTypeConverter : TypeConverter
	{
		public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
		{
			if (sourceType == typeof(ArchetypeModel))
				return true;

			return base.CanConvertFrom(context, sourceType);
		}

		public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
		{
			if (value is ArchetypeModel)
				return ConvertFromArchetype((ArchetypeModel)value);

			return base.ConvertFrom(context, culture, value);
		}

		private MetaData ConvertFromArchetype(ArchetypeModel value)
		{
			var fieldset = value.FirstOrDefault();
			if (fieldset == null)
				return null;

			return new MetaData()
			{
				Title = fieldset.GetValue<string>("metaTitle"),
				Description = fieldset.GetValue<string>("metaDescription"),
				Keywords = fieldset.GetValue<string>("metaKeywords")
			};
		}
	}
}