Entity Framework 5 - Looking for Central Point to Execute Custom Code after Entity is Loaded from Database

Question

I am using Entity Framework 5 with Code First approach and using Fluent API for Entity configuration. My project has one particular Product Entity which gets half of its dat

Answer 1

Today I found an event in the Entity Framework that seems to be what I am looking for. ObjectContext.ObjectMaterialized Event. Apparently, DbContext implements IObjectContextAdapter which in-turn exposes the ObjectContext. From there I can subscribe to the ObjectMaterialized event.

MSDN Reads: Occurs when a new entity object is created from data in the data source as part of a query or load operation.

The following code demonstrates how I used the ObjectMaterialized event to solve my problem in which one of my preferences was to have a central point to place the WCF client access logic.

// seperate assembly - does not use Domain.Repositories assembly
namespace Domain.Models
{
    // the data contract
    [DataContract]
    public class ProductInventoryState
    {
        [DataMember]
        public int StockStatus { get; set; }

        [DataMember]
        public IEnumerable SerialNumbers { get; set; }

        // etc....
    }

    // the entity
    public class Product
    {
        public Guid Key { get; set; }
        public string ProductCode { get; set; }
        public ProductInventoryState InventoryState { get; set; }
        // etc....
    }
}

// seperate assembly - uses Domain.Models assembly
namespace Domain.Repositories
{
    public class MainRepository : DbContext
    {
        public MainRepository()
        {
            ((IObjectContextAdapter)this).ObjectContext.ObjectMaterialized += ObjectContext_ObjectMaterialized;
        }

        protected void ObjectContext_ObjectMaterialized(object sender, ObjectMaterializedEventArgs e)
        {
            if (e.Entity == null)
                return;

            if (e.Entity is Product)
            {
                Product product = (Product)e.Entity;

                // retrieve ProductInventoryState from 3rd party SOAP API
                using (ThirdPartyInventorySystemClient client = new ThirdPartyInventorySystemClient())
                {
                    // use ProductCode to retrieve the data contract
                    product.InventoryState = client.GetInventoryState(product.ProductCode);
                }
            }
        }    
    }
}