Telerik Openaccess & Linq compiled expression

[Matteo Ermidoro]

Hello, 

I'm trying to create a "generic" datalayer for my apps. At the moment I'm facing some issue creating a method with this sign :

public T GetSingle<T>(Expression<Func<T, bool>> filter)

I want to use Expression<Func<T, bool>> filter to pass "where" statement to my DAL. 

My code is : 

            var predicate = filter.Compile();

            var scope = ObjectScopeProvider.ObjectScope(ScopeContext.Application);           

            var obj1 = scope.Extent<T>().Where<T>(p => predicate(p));

but with no luck, last row throw this exeption :

System.NotSupportedException was unhandled

  Message="RegionExtent.OfType().Where(p => Invoke(value(OfeX.DataLayer.DatabaseServices.DataBaseServices+<>c__DisplayClass0`1[OfEx.PersistentClasses.Region]).predicate,p))"

  Source="Telerik.OpenAccess.Query"

  StackTrace:

       at Telerik.OpenAccess.Query.QueryContext.CreatedQuery(IQueryable x)

       at Telerik.OpenAccess.Query.QueryContext.CreatedQuery[T](IQueryable`1 x)

       at Telerik.OpenAccess.Query.ObjectScopeQuery`2.CreateQuery[TElement](Expression expressionParam)

       at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate)

       at OfeX.DataLayer.DatabaseServices.DataBaseServices.GetSingle[T](Expression`1 filter) in C:\Data\Visual Studio 2005\Projects\OfEx\Ofex\Ofex.DataLayer\DatabaseServices\DataBaseServices.cs:line 74

       at TestDataLayer.Form1.button3_Click(Object sender, EventArgs e) in C:\Data\Visual Studio 2005\Projects\OfEx\Ofex\TestDataLayer\Form1.cs:line 56

       at System.Windows.Forms.Control.OnClick(EventArgs e)

       at System.Windows.Forms.Button.OnClick(EventArgs e)

       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)

       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)

       at System.Windows.Forms.Control.WndProc(Message& m)

       at System.Windows.Forms.ButtonBase.WndProc(Message& m)

       at System.Windows.Forms.Button.WndProc(Message& m)

       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)

       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)

       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)

       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)

       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)

       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)

       at System.Windows.Forms.Application.Run(Form mainForm)

       at TestDataLayer.Program.Main() in C:\Data\Visual Studio 2005\Projects\OfEx\Ofex\TestDataLayer\Program.cs:line 18

       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)

       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)

       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()

       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)

       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

       at System.Threading.ThreadHelper.ThreadStart()

  InnerException: 

Anyone could help? 

Thanks a lot.

Matteo

-------------------------------------------------------

Solved : 

Seems to be a problem with OpenAccess & "var predicate = filter.Compile();".

I modified the last row in 

var obj1 = scope.Extent<T>().Where<T>(filter);

and now it works.

Thanks 

Matteo