Introducing the Composite Data Service Framework

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Services.Providers;
using System.Data.Metadata.Edm;
using System.Data.Objects;

namespace CompositeDataServiceFramework.Server
{
    public static class EntityToResourceMapping
    {

        public static ResourceType MapEntityType(EntityType entityType, ObjectContext context, string namespaceName)
        {
            //  *** How do we get the CLR tye/
            string parentNamespace = context.GetType().Namespace;
            var ss = context.GetType().Assembly;
            var type = (from t in ss.GetTypes() where t.Name == entityType.Name select t).FirstOrDefault();

            //  Create the resource type.
            ResourceType resourceType = new ResourceType(
              type,
              ResourceTypeKind.EntityType,
              null, // base types not supported.
              namespaceName,
              entityType.Name,
              entityType.Abstract
              );

            //  Add each property.
            //  *** TODO ***
            //  Complex types are not supported. We assume the first property is the key.
            //  Navigation types are not supported.
            bool first = true;
            foreach (var propertyType in entityType.Properties)
            {
                ResourcePropertyKind kind = ResourcePropertyKind.Primitive;
                if (first)
                {
                    kind |= ResourcePropertyKind.Key;
                    first = false;
                }

                var resourceProperty = new ResourceProperty(
                       propertyType.Name,
                       kind,
                       MapEdmType(propertyType.TypeUsage.EdmType)
                    );
                resourceType.AddProperty(resourceProperty);
            }
            
            return resourceType;
        }

        private static ResourceType MapEdmType(EdmType edmType)
        {
            if (edmType is PrimitiveType)
                return ResourceType.GetPrimitiveResourceType(((PrimitiveType)edmType).ClrEquivalentType);
            throw new Exception("Don't know type " + edmType.Name);
        }
    }
}