BOSFetch - How to have DevForce find it...

I have implemented a BOF class as follows, but no matter what I set I cannot get this detected by the probe, and the log error is always:

IdeaBlade.EntityModel.Server

EntityServer::GetInstanceImplementing

Unable to locate an implementation of: IdeaBlade.EntityModel.IEntityServerFetching

I've even moved this code into a new assembly, included that reference in the web project, added to the <probeAssemblyNames> in web.config (and checked it is picked up by renaming it and I get an error), yet I always get this report in the log file.

Does the class require a specific namespace, must it be static, or what?

Can you please post a working example project so I (and presumably others) can work out how to implement this?

Cheers,
 Jason


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using IdeaBlade.EntityModel;
using System.Diagnostics;
using System.Linq.Expressions;

public class BOSFetch : IEntityServerFetching
{
    // EXAMPLE:
    //void OnFetching(object sender, EntityFetchingEventArgs e)
    //{
    //    if (e.Query.ReturnType == typeof(Product))
    //    {
    //        int wholesalerid = GetWhilesalerId(HttpContext.Current.User.Identity.Name);
    //        iRisk.DataModel.iRiskEntities de = new iRisk.DataModel.iRiskEntities();
    //        e.Query.Filter = new Filter(p => p.Wholesaler.WholesalerID == wholesalerid);
    //    }
    //}

    #region IEntityServerFetching Members

    public void OnFetching(EntityServerFetchingEventArgs args)
    {
        Debug.WriteLine("OnFetching - " + args.Query.ToString());
        //((EntityQuery)args.Query).Filter(
        ////args.Principal.Identity.Name
        //if (args.Query.ReturnType == typeof(Portfolio))
        //{
        //    string uname = args.Principal.Identity.Name;
        //    //var qry = ((IEntityQueryable<Portfolio>)args.Query).Where(p => true); //.Where(p => p.Client.Username == uname);
        //    //args.Query = (qry as IEntityQuery<Portfolio>);
        //}
    }

    #endregion

}

Since this class is in the main application, why would it require a fully qualified name and version?

Probing for an IEntityServerFetching implementation uses only the top level <probeAssemblyNames> in the ideablade.configuration section, not the probes defined for an EdmKey.  There are no other requirements for the implementation - it does not have to be a static class, in a specific namespace, etc.  The class just needs to implement the interface, and be found within one of the non-EdmKey probe assemblies in the web.config.   You can use the Config Editor if you're unsure of the elements available and their locations.

We plan to include a tutorial showing implementation of IEntityServerFetching, along with other "server side" interfaces, within the next few releases.  The next release will also include an IEntityServerFetching example as part of a Silverlight ASP.NET security sample, but as you'll soon see, there's really nothing complicated about this interface.

Hmm, I need to see why we don't provide an EntityManager as an argument to the method.

This should work:
   var em = EntityManager.DefaultManager;
   var dom = new DomainModelEntityManager(em);

Ah, I suspect the second SQL was a lazy load of a joined table row, as the following generates the SQL I would expect:

            args.Query = ((EntityQuery)args.Query).Filter(
                (IQueryable<dimStation> stat) =>
                    (from s in stat join p in dom.permissions on s.StationId equals p.StationId where p.Username == args.Principal.Identity.Name select s).AsQueryable());
Returns:
SELECT
[Extent1].[StationId] AS [StationId],
[Extent1].[Station] AS [Station]
FROM  [dbo].[dimStation] AS [Extent1]
INNER JOIN [dbo].[permissions] AS [Extent2] ON ([Extent1].[StationId] = [Extent2].[StationId]) OR (([Extent1].[StationId] IS NULL) AND ([Extent2].[StationId] IS NULL))
WHERE (N'Jason' = [Extent2].[Username]) AND ([Extent1].[StationId] < 100)

Perfect!
I'd still like to know how to use the SessionBundle though. Can I add data to it? I'd like to store an integer UserId somewhere in 'session' for these calls (instead of Username). Is this the right place?

Cheers,
 Jason