Persistence Ignorance (POCO) Adapter for Entity Framework V1

Persistence Ignorance (POCO) Adapter for Entity Framework V1 : EasyCoded

Persistence Ignorance (POCO) Adapter for Entity Framework V1 : EasyCoded — Tue, 09 Sep 2008 20:01:26 GMT

PingBack from http://www.easycoded.com/persistence-ignorance-poco-adapter-for-entity-framework-v1/

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

rogerj — Tue, 09 Sep 2008 20:43:19 GMT

Does Astoria consider the POCO Adapter's EFPocoContext a first-class data source, that is, supports IQueryable<T> and induces the Astoria runtime to provide IUpdatable<T>.

In other words, can it be plugged into an Astoria project without adding a significant amount of code?

Thanks in advance,

--rj

Jarek publishes his excellent Entity Framework POCO Adapter

Diego Vega — Tue, 09 Sep 2008 20:50:07 GMT

I have been back from vacation for some time but I haven't had time to post anything (i.e. I was on vacation

Persistence Ignorance (POCO) Adapter for Entity Framework

BlogCoward — Tue, 09 Sep 2008 23:50:57 GMT

Persistence Ignorance (POCO) Adapter for Entity Framework

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Wed, 10 Sep 2008 02:23:41 GMT

Roger,

I'll investigate the Astoria question, but since EFPocoAdapter does not implement IUpdatable I don't think it works now.

Implementation of IUpdatable should be pretty straightforward, though.

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Wed, 10 Sep 2008 04:31:01 GMT

OK. I have played with Astoria and I was able to get a basic service to work. All you have to do is to derive from DataService<adapterContextType>, such as:

public class NorthwindEFService : DataService<NorthwindEntitiesAdapter>

{

}

This makes use of the "second face" of the object model, which is the EF-compatible adapter layer. Astoria doesn't have a clue that it is talking to POCO model, but the EF-POCO translation happens under the hood.

Jarek propose un adapter POCO pour EF

Matthieu MEZIL — Wed, 10 Sep 2008 09:00:30 GMT

Après avoir proposé une solution pour faire du Lazy Loading avec EF v1, Jarek propose maintenant une

Persistence Ignorance (POCO) Adapter for Entity Framework V1

DotNetKicks.com — Wed, 10 Sep 2008 10:03:08 GMT

You've been kicked (a good thing) - Trackback from DotNetKicks.com

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

Damon Wilder Carr — Wed, 10 Sep 2008 15:58:44 GMT

Nice.. We are finishing the same style of work that we have a large regression base for Linq to NHibernate, Linq to SQL and Linq to EF all via the same type of solution you've done here it appears.

Our design goal is to allow not only persistence ignorance for entities but also to allow transport ignorance for repository services. The two main scenarios we are testing is in-proc and WCF.

It does get interesting with serialization as moving say an NHibernate set over WCF to a presenter/controller and even using a cool TypeDescriptor technique we use for 'flattening' a one-many result into a grid (using ITypedList as a key piece) for 2-way data binding and then moving it back for updates is non-trivial and we're still deciding just how much we want to get involved with writing yet another sync solution for updates (we do not want to of course)...

Anyway, nice work again.

Damon

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

rogerj — Wed, 10 Sep 2008 18:37:23 GMT

Jarek,

Thanks for the Astoria test. I'll give it a try later this week or weekend.

--rj

Le POCO enfin disponible sur l'Entity Framework

WithArt Blog — Wed, 10 Sep 2008 19:50:49 GMT

Le POCO enfin disponible sur l'Entity Framework

Entity Framework enfin compatible POCO

WithArt Blog — Wed, 10 Sep 2008 21:32:09 GMT

Entity Framework enfin compatible POCO

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Wed, 10 Sep 2008 23:47:14 GMT

I've published a minor update (v1.01) to Code Gallery that fixes a problem where you cannot generate an adapter when you don't pass /ref: parameter and your model contains a collection.

Also, added caching of RelatedEnds in the generated code which will provide much faster DetectChanges() by eliminating metadata lookups.

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

CoreyGaudin — Sat, 13 Sep 2008 10:52:56 GMT

I noticed a problem on File EFPocoContext.cs Line 165:

You need to change that line to the following 2 lines (on grabbing the AdapterCreators cached on the function GetAdapterObject):

Type entityType = (entity is IEntityProxy ? entity.GetType().BaseType : entity.GetType());

Func<object, IPocoAdapter> adapterCreator = _queryTranslationCache.AdapterCreators[entityType];

The cache of Adapter Creators does not create an equivalent for the Proxies. So if you use a proxy to change one of its references, it will bomb with no key found. This change will see if it is a proxy, and get its base which will always be the model object (instead of creating n x 2 cache items - so that should be a faster way to tackle it).

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Sat, 13 Sep 2008 17:51:28 GMT

CoreyGaudin:

I was able to reproduce the bug with the following simple test, which is failing on v1.01:

[TestMethod]

public void GetAdapterObjectDoesNotWorkForProxiesBug()

{

using (NorthwindEntities context = new NorthwindEntities())

{

var customerProxy = context.CreateObject<Customer>();

Assert.IsTrue(context.IsProxy(customerProxy));

var adapterObject = context.GetAdapterObject(customerProxy);

Assert.AreSame(customerProxy, adapterObject.PocoEntity);

}

Is this your scenario?

I have a fix for it (different than you suggested - I'm basically making sure that the situation where you have a proxy, but its adapter is not cached is not possible).

I will add a bunch of asserts and tests to verify this, would you be interested in verifying the fix with your application before I make it public? If so, please drop me a line at jaroslaw dot kowalski at microsoft dot com.

Create a proxy object doesnt work correctly.

CoreyGaudin — Sat, 13 Sep 2008 23:44:52 GMT

Your create proxy object doesnt work correctly if that object has a reference objects and entities.

In the example you used above:

context.CreateObject<Customer>();

If customer had a related object Orders, then if you try to set that to a new Order for that customer, the Order throws an error, because it cant find a order (even though its a new customer and shouldnt have an order).

Is there any way around this? I want a Proxy object so I can manipulate it and in the end save it without doing a massive attach at the end which would be expensive.

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Sun, 14 Sep 2008 03:06:01 GMT

Both issues reported by Corey have been resolved in a new release of EFPocoAdapter v1.02:

http://blogs.msdn.com/jkowalski/archive/2008/09/13/ef-poco-adapter-updated-v1-02.aspx

Mehr POCO (Plain Old CLR Objects) UND Entity Framework - Der "Persistence Ignorance (POCO) Adapter for Entity FRAMEWORK V1" ...

Mostly Technical Content — Fri, 24 Oct 2008 13:58:30 GMT

In diesem Blogs habe ich schon 2-mal über die Themen Entity Framework und POCO geschrieben. Aus

Entities as interfaces vs. Linq to Entities revisited and lost

Lars-Erik's blog — Mon, 19 Jan 2009 22:06:23 GMT

I'm following up on that case here, still clinging to some hope: http://forums.microsoft.com/MSDN

#.think.in infoDose #19 (23rd Feb - 27th Feb)

#.think.in — Mon, 02 Mar 2009 05:07:09 GMT

#.think.in infoDose #19 (23rd Feb - 27th Feb)

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

Tanveer Badar — Fri, 06 Mar 2009 18:26:30 GMT

It is great work Jaroslaw. I appreciate if from the depths of my heart.

But if everyone is trying to improve EF v1 in some way, adding obvious features like proper change tracking, PI etc. doesn't it say a lot about how half-baked solution EF is?

Most of these problems will still remain in v2, why should anyone use EF when there are better, more complete ORM solutions out there.

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

jkowalski — Fri, 06 Mar 2009 19:14:17 GMT

Lack of POCO support was probably the biggest pain point of the first release of Entity Framework.

Let me assure you that we are addressing that problem in the next version by supporting pure POCO objects. We are also making big investments in other areas, such as N-tier support, lazy loading and many others which will greatly improve developer experience. EF Design Blog (http://blogs.msdn.com/efdesign) has lots of information about new features coming in EF v4.0 and many more exciting posts will be published there.

re: Persistence Ignorance (POCO) Adapter for Entity Framework V1

Courtois — Fri, 17 Apr 2009 18:24:35 GMT

Nice job !

but i have a quesstion how can i execute "import function" via the adapter ?

I would like something like that:

IList<T> ExecuteFunction<T>("MyFunction", myObjectParameter)

What is POCO - Entity Framework

Sriram's WebLog on ASP.NET VB.NET C# — Wed, 13 May 2009 04:57:38 GMT

Ever wondered about what is POCO? POCO stands for Plain Old CLR Object which does not have any persistence

Problem with POCO Adapter for Entity Framework V1

gutemberg.ribeiro — Fri, 19 Jun 2009 02:09:36 GMT

Hi Joraslaw!

Thanks for the great post about this great EF v1 extension.

So, I had some problems with it and posted into discussion list of MSDN Code portal.

Above the link direct for the discussion I really appreciate if you can take a look and see if u can help me.

Best regards...

http://code.msdn.microsoft.com/EFPocoAdapter/Thread/View.aspx?ThreadId=1893

Gutemberg Ribeiro