Join Multiple Transactions Across Instances of EF Connections - entity-framework-4

I have the following setup in my Data Layer
namespace DAL
{
public abstract class BaseDalObj:IDisposable
{
protected Auto.Entities entities;
public BaseDalObj()
{
entities= new Auto.Entities();
}
public void Dispose()
{
}
}
public class Class1: BaseDalObj
{
public void Save(object a)
{
entities.SaveItem(a);
}
}
public class Class2: BaseDalObj
{
public void Save(object b)
{
entities.SaveItem(b);
}
}
}
namespace Business
{
public class BusinessLL
{
public Object a,b;
public BusinessDAL()
{
a = new Object();
b = new Object();
}
public void Save()
{
using(var dbObj1 = new DAL.Class1())
{
dbObj1.Save(a);
using(var dbObj2 = new DAL.Class2())
{
dbObj2.Save(b);
}
}
}
}
}
what I would like is some way to call both Save functions but within the same TransactionScope.
I have no idea how i can do this using EF. I have looked into using the TransactionScope Class but I cannot get to grips with how it works.
I have been looking at using the entities.Connection.BeginTransaction() but that returns a DbTransaction and TransactionScope only accepts a type Transaction Class
Any help or pointers that can point me in the right way would really help.

If there is an ambient transaction present when opening a connection the connection will automatically enlist into this transaction. This applies to the ObjectContext too - when you call ObjectContext.SaveChanges it will automatically enlist the connection into the ambient transaction.
Therefore, I think this should work:
using(var transaction = new TransactionScope)
{
using(var class1 = new Class1())
{
class1.Save(x);
}
using(var class2 = new Class2())
{
class2.Save(y);
}
transaction.Complete();
}

Related

Error while creating plugin in Nop Commerce

This is my first demo project in Nopcommerce and i have tried to make my own plugin but during the time of Build some error is seen. Below are some codes.
namespace Nop.Plugin.Aowi.Testimonial.Data
{
public class TestimonialRecordObjectContext : DbContext , IDbContext
{
public TestimonialRecordObjectContext(string nameOrConnectionString) : base(nameOrConnectionString) { }
#region Implementation of IDbContext
#endregion
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new TestimonialRecordMap());
base.OnModelCreating(modelBuilder);
}
public string CreateDatabaseInstallationScript()
{
return ((IObjectContextAdapter)this).ObjectContext.CreateDatabaseScript();
}
public void Install()
{
//It's required to set initializer to null (for SQL Server Compact).
//otherwise, you'll get something like "The model backing the 'your context name' context has changed since the database was created. Consider using Code First Migrations to update the database"
Database.SetInitializer<TestimonialRecordObjectContext>(null);
Database.ExecuteSqlCommand(CreateDatabaseInstallationScript());
SaveChanges();
}
public void Uninstall()
{
var dbScript = "DROP TABLE Testimonial";
Database.ExecuteSqlCommand(dbScript);
SaveChanges();
}
public new IDbSet<TEntity> Set<TEntity>() where TEntity : BaseEntity
{
return base.Set<TEntity>();
}
public System.Collections.Generic.IList<TEntity> ExecuteStoredProcedureList<TEntity>(string commandText, params object[] parameters) where TEntity : BaseEntity, new()
{
throw new System.NotImplementedException();
}
public System.Collections.Generic.IEnumerable<TElement> SqlQuery<TElement>(string sql, params object[] parameters)
{
throw new System.NotImplementedException();
}
public int ExecuteSqlCommand(string sql, bool doNotEnsureTransaction = false, int? timeout = null, params object[] parameters)
{
throw new System.NotImplementedException();
}
}
}
This is the Dependency registrar part
namespace Nop.Plugin.Aowi.Testimonial.Infastructure
{
public class DependencyRegistrar: IDependencyRegistrar
{
private const string CONTEXT_NAME ="nop_object_context_product_view_tracker";
public virtual void Register(ContainerBuilder builder, ITypeFinder typeFinder, NopConfig config)
{
//data context
this.RegisterPluginDataContext<TestimonialRecordObjectContext>(builder, CONTEXT_NAME);
//override required repository with our custom context
builder.RegisterType<EfRepository<TestimonialRecord>>()
.As<IRepository<TestimonialRecord>>()
.WithParameter(ResolvedParameter.ForNamed<IDbContext>(CONTEXT_NAME))
.InstancePerLifetimeScope();
}
public int Order
{
get { return 1; }
}
}
}
Even after cleaning and Building i am getting this error.
Can anyone help me with this. I have done all of this by watching a tutorial so if anyone can help me correct my mistake i will be really greatful.
You just need to implement this method and properties of IDbContext interface, which are described in error log, in your custom context.
for example, how it is done in one of the existing plugin Tax.CountryStateZip:
public void Detach(object entity)
{
if (entity == null)
throw new ArgumentNullException("entity");
((IObjectContextAdapter)this).ObjectContext.Detach(entity);
}
public virtual bool ProxyCreationEnabled
{
get { return this.Configuration.ProxyCreationEnabled; }
set { this.Configuration.ProxyCreationEnabled = value; }
}
public virtual bool AutoDetectChangesEnabled
{
get { return this.Configuration.AutoDetectChangesEnabled; }
set { this.Configuration.AutoDetectChangesEnabled = value; }
}
I cannot get an idea from your code that where is actual issue. But i suggest by an example.
make your install method code like:
public void Install()
{
//create the table
var dbScript = CreateDatabaseScript();
Database.ExecuteSqlCommand(dbScript);
SaveChanges();
}
Add a new class called EfStartUpTask and paste following code:
public class EfStartUpTask : IStartupTask
{
public void Execute()
{
//It's required to set initializer to null (for SQL Server Compact).
//otherwise, you'll get something like "The model backing the 'your context name' context has changed since the database was created. Consider using Code First Migrations to update the database"
Database.SetInitializer<YourContext>(null);
}
public int Order
{
//ensure that this task is run first
get { return 0; }
}
}
And your DependencyRegistrar :
public class DependencyRegistrar : IDependencyRegistrar
{
public virtual void Register(ContainerBuilder builder, ITypeFinder typeFinder)
{
builder.RegisterType<YourService>().As<YourserviceInterface>().InstancePerLifetimeScope();
//data context
this.RegisterPluginDataContext<YourContext>(builder, "nop_object_context_product_view_tracker");
//override required repository with our custom context
builder.RegisterType<EfRepository<YourEntityClass>>()
.As<IRepository<YourEntityClass>>()
.WithParameter(ResolvedParameter.ForNamed<IDbContext>("nop_object_context_product_view_tracker"))
.InstancePerLifetimeScope();
}
public int Order
{
get { return 1; }
}
}
Note: you have to change YourContext to your context name and same as for entity class
Hope this helps!

Ninject Conditional Self bind to change scope (For Task-scheduler) not working properly?

Within MVC Web Application DbContext binding work properly with InRequestScope()
kernel.Bind<DbContext>().ToSelf().InRequestScope();
kernel.Bind<IUnitOfWork<DbContext>>().To<UnitOfWork<DbContext>>();
But from a Task Scheduler call DbContext in InRequestScope() unable to update Db Table (without any error), until I change Binding to InSingletonScope() OR InThreadScope()
Question: So is their any way change scope to InSingletonScope() / InThreadScope() for a Task Scheduler Call. ?
// For Task Scheduler Call, I tried bellow bind, but not working properly
kernel.Bind<DbContext>().ToSelf()
.When(request => request.Target.Type.Namespace.StartsWith("NameSpace.ClassName"))
.InSingletonScope();
** And probably I miss some thing. Need help.
Code Snippet Updated
#region Commented Code
public EmailTask() : this
( DependencyResolver.Current.GetService<IMessageManager>(),
, DependencyResolver.Current.GetService<IUnitOfWork<DbContext>>()) { }
#endregion
public EmailTask(IMessageManager messageManager, IUnitOfWork<DbContext> unitOfWork)
{
this._messageManager = messageManager;
this._unitOfWork = unitOfWork;
ProcessEmail();
}
public class NonRequestScopedParameter : IParameter { ... }
public void ProcessEmail()
{
var temp = SomeRepository.GetAll();
SendEmail(temp);
temp.Date = DateTime.Now;
SomeRepository.Update(temp);
unitOfWork.Commit();
}
public class ExecuteEmailTask : ITask
{
private readonly IResolutionRoot _resolutionRoot;
private int _maxTries = 5;
public ExecuteEmailTask(IResolutionRoot resolutionRoot)
{
_resolutionRoot = resolutionRoot;
}
public void Execute(XmlNode node)
{
XmlAttribute attribute1 = node.Attributes["maxTries"];
if (attribute1 != null && !String.IsNullOrEmpty(attribute1.Value))
{
this._maxTries = int.Parse(attribute1.Value);
}
/// send email messages
var task = _resolutionRoot.Get<EmailTask>(new NonRequestScopedParameter());
}
}
In Web.Config
<ScheduleTasks>
<Thread seconds="60">
<task name="ExecuteEmailTask" type="namespace.ExecuteEmailTask, AssemblyName" enabled="true" stopOnError="false" maxTries="5"/>
</Thread>
</ScheduleTasks>
In Global.asax
protected void Application_Start()
{
/* intialize Task */
TaskConfig.Init();
TaskManager.Instance.Initialize(TaskConfig.ScheduleTasks);
TaskManager.Instance.Start();
}
Ninject Bind Syntax
kernel.Bind<DbContext>().ToSelf().InRequestScope(); // Default bind
kernel.Bind<DbContext>().ToSelf()
.When(x => x.Parameters.OfType<NonRequestScopedParameter>().Any())
.InCallScope(); // For Scheduler
Note: EmailTask class also have SomeReposity as a Constructor Argument.
Queries:-
But what is the bind syntax to resolve TaskScheduler(IResolutionRoot resolutionRoot) ?
What is the configuration code to run TaskScheduler ?
As say to put IFakeDbContext directly into constructor, can this work with IUnitOfWork<FakeDbContext> ?
Problem
Task unable to call with Overloaded Constructor , it is only able to call TaskScheduler default Constructor.
Question 4: Can any way to invoke TaskScheduler(IResolutionRoot resolutionRoot) from TaskScheduler default constructor ?
Sample Code Snippet to create Task & run using System.Threading.Timer
private ITask createTask()
{
if (this.Enabled && (this._task == null))
{
if (this._taskType != null)
{
this._task = Activator.CreateInstance(this._taskType) as ITask;
}
this._enabled = this._task != null;
}
return this._task;
}
Question 5: Can I resolve TaskScheduler(IResolutionRoot resolutionRoot) here ?
Solved
public ExecuteEmailTask() :
this(DependencyResolver.Current.GetService<IResolutionRoot>())
OR
public ExecuteEmailTask() : this(new Bootstrapper().Kernel) { }
public ExecuteEmailTask(IResolutionRoot resolutionRoot)
{
_resolutionRoot = resolutionRoot;
}
First of, you should note that InSingletonScope() is usually a bad idea for DbContext's/Sessions. What happens if some other service changes data in the meantime? I would recommend investigating what effects this has.
For the scenario you first described, a correctly formulated .When(...) should work.
As an alternative to the .When(...) binding you could also use a .Named("FooBar") binding.
The constructor of the scheduled task would then need to look like:
ctor(Named["FooBar"] DbContext dbContext);
However, note, that this only (easily) works in case you need to inject the DbContext into a single constructor. If the task features dependencies and these need the same DbContext instance, too, it gets a bit tricker.
Since you updated your answer and say that this is the case, i would recommend an entirely different approach: Using a request parameter as basis for the When(...) condition combined with InCallScope binding. See below for an example.
Brace yourself, this is ab it of code :) The implementation requires the ninject.extensions.NamedScope extension (nuget).
I've also used xUnit and FluentAssertions nuget packages to execute the tests.
public class Test
{
// the two implementations are just for demonstration and easy verification purposes. You will only use one DbContext type.
public interface IFakeDbContext { }
public class RequestScopeDbContext : IFakeDbContext { }
public class CallScopeDbContext : IFakeDbContext { }
public class SomeTask
{
public IFakeDbContext FakeDbContext { get; set; }
public Dependency1 Dependency1 { get; set; }
public Dependency2 Dependency2 { get; set; }
public SomeTask(IFakeDbContext fakeDbContext, Dependency1 dependency1, Dependency2 dependency2)
{
FakeDbContext = fakeDbContext;
Dependency1 = dependency1;
Dependency2 = dependency2;
}
}
public class Dependency1
{
public IFakeDbContext FakeDbContext { get; set; }
public Dependency1(IFakeDbContext fakeDbContext)
{
FakeDbContext = fakeDbContext;
}
}
public class Dependency2
{
public IFakeDbContext FakeDbContext { get; set; }
public Dependency2(IFakeDbContext fakeDbContext)
{
FakeDbContext = fakeDbContext;
}
}
public class TaskScheduler
{
private readonly IResolutionRoot _resolutionRoot;
public TaskScheduler(IResolutionRoot resolutionRoot)
{
_resolutionRoot = resolutionRoot;
}
public SomeTask CreateScheduledTaskNow()
{
return _resolutionRoot.Get<SomeTask>(new NonRequestScopedParameter());
}
}
public class NonRequestScopedParameter : Ninject.Parameters.IParameter
{
public bool Equals(IParameter other)
{
if (other == null)
{
return false;
}
return other is NonRequestScopedParameter;
}
public object GetValue(IContext context, ITarget target)
{
throw new NotSupportedException("this parameter does not provide a value");
}
public string Name
{
get { return typeof(NonRequestScopedParameter).Name; }
}
// this is very important
public bool ShouldInherit
{
get { return true; }
}
}
[Fact]
public void FactMethodName()
{
var kernel = new StandardKernel();
// this is the default binding
kernel.Bind<IFakeDbContext>().To<RequestScopeDbContext>();
// this binding is _only_ used when the request contains a NonRequestScopedParameter
// in call scope means, that all objects built in the a single request get the same instance
kernel.Bind<IFakeDbContext>().To<CallScopeDbContext>()
.When(x => x.Parameters.OfType<NonRequestScopedParameter>().Any())
.InCallScope();
// let's try it out!
var task = kernel.Get<SomeTask>(new NonRequestScopedParameter());
// verify that the correct binding was used
task.FakeDbContext.Should().BeOfType<CallScopeDbContext>();
// verify that all children of the task get injected the same task instance
task.FakeDbContext.Should()
.Be(task.Dependency1.FakeDbContext)
.And.Be(task.Dependency2.FakeDbContext);
}
}
Since, as you say, the task scheduler does not make use of the IoC to create the task, it only supports a parameterless constructor. In that case you can make use DependencyResolver.Current (however, note that i'm in no way an expert on asp.net /MVC so i'm not making any claims that this is thread safe or working 100% reliably):
public class TaskExecutor : ITask
{
public TaskExecutor()
: this(DependencyResolver.Current.GetService<IResolutionRoot>())
{}
internal TaskExecutor(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public void Execute()
{
IFooTask actualTask = this.resolution.Get<IFooTask>(new NonRequestScopedParameter());
actualTask.Execute();
}
}

Autofac, multiple interfaces to same implementation per HTTP request in ASP.NET MVC

My DbContext implementation implements two interfaces.
I'm trying to follow best practices and instantiate one DbContext instance per HTTP request.
However, I have a controller action where I need to instantiate two classes, each of which takes different interface in constructor.
I am worried if in that scenario, for that specific action, two DbContext instances would be raised.
I've setup my ContainerBuilder like this:
builder.RegisterType<MyDbContext>()
.As<IWorkflowPersistenceStore>()
.As<IDocumentPersistenceStore>()
.InstancePerHttpRequest();
builder.RegisterType<WorkflowManager>().As<IWorkflowManager>().InstancePerHttpRequest();
builder.RegisterType<DocumentManager>().As<IDocumentManager>().InstancePerHttpRequest();
public class OperationController : Controller
{
private IWorkflowManager _workflowManager;
private IDocumentManager _documentManager;
public OperationController(IWorkflowManager workflowManager, IDocumentManager documentManager)
{
_workflowManager = workflowManager;
_documentManager = documentManager;
}
public ActionResult SaveWorkflowDocument(...)
{
// will my managers point to same DbContext?
_workflowManager.DoSomething(...);
_documentManager.DoSomethingElse(...);
return View();
}
}
public class WorkflowManager : IWorkflowManager
{
private IWorkflowPersistenceStore _store;
public WorkflowManager(IWorkflowPersistenceStore store)
{
_store = store;
}
}
public class DocumentManager : IDocumentManager
{
private IDocumentPersistenceStore _store;
public DocumentManager (IDocumentPersistenceStore store)
{
_store = store;
}
}
Is this good enough?
Do I have to add .SingleInstance()? I'm worried that it might create singleton for whole application.
I think you're ok with what you have. Test passes:
using Autofac;
using NUnit.Framework;
namespace AutofacTest
{
[TestFixture]
public class ScopeTest
{
[Test]
public void Test()
{
var builder = new ContainerBuilder();
builder.RegisterType<Component>()
.As<IServiceA>()
.As<IServiceB>()
.InstancePerLifetimeScope();
using (var container = builder.Build())
using (var scope = container.BeginLifetimeScope())
{
var a = scope.Resolve<IServiceA>();
var b = scope.Resolve<IServiceB>();
Assert.AreEqual(a, b);
}
}
}
public interface IServiceA { }
public interface IServiceB { }
public class Component : IServiceA, IServiceB { }
}

Unit Testing a mock WCF client

I'm having serious issues in how to deploy a WCF client in a MVC site which is easily testable. I'm struggling to set up a mock of the service without actually accessing a endpoint.
Example Controller of site under test
public class ProfileController : ControllerExtended
{
public ProfileController(IUserService membershipService, IDropDownService dropdownService, ISiteService siteService)
{
WCFService.Instance.Client = siteService; //Should maybe be a serpate service.
_membershipService = membershipService;
_dropDownService = dropdownService;
_siteService = siteService;
}
public ActionResult Index()
{
UserComp profile = _siteService.ProfileGet(_sharedContext.CurrentUser.id);
return View(new ProfileViewModel { Profile = profile });
}
}
WCF Singleton (I think my implementation of WCF is my issue, should it be in a interface?)
public sealed class WCFService
{
public SiteServiceI Client { get; set; }
#region Singleton
static readonly WCFService query = new WCFService();
static WCFService()
{
}
WCFService()
{
}
public static WCFService Instance
{
get { return query; }
}
#endregion
}
UnitTest
[TestFixture]
public class UnitTest1
{
private Mock<SiteService> mockSiteService;
private Mock<IUserService> mockMembershipService;
private Mock<IDropDownService> mockDropDown;
private Mock<SiteServiceIClient> mockServiceClient; //new Mock<SiteServiceIClient>();
//private Mock<WebService> mockWebService;
[SetUp]
public void SetUp()
{
mockSiteService = new Mock<ISiteService>();
mockMembershipService = new Mock<IUserService>();
mockDropDown = new Mock<IDropDownService>();
mockServiceClient = new Mock<SiteServiceIClient>();
mockWebService = new Mock<WebService>(mockServiceClient);
}
[Test]
public void CheckHomeIndex_Controller()
{
var controller = new HomeController(mockMembershipService.Object, mockDropDown.Object, mockPTSearch.Object, mockServiceClient.Object); // mockServiceClient times out.
Assert.AreEqual("this", "this");
}
}
I assume the errors are occurring because the singleton sets the service up as soon as it is initialised. I've tried to implement a separate service purely for called to WCF but not had success in implementing it in a testable manner. Not too sure if this is to vague but I've read a lot on it and not an closer.
The singleton is definitely your problem - testing with singletons is entering a world of pain. You should implement a facade pattern to make this testing friendly. Something like this:
public interface IServiceFacade
{
Profile ProfileGet(int id);
}
public class ServiceFacade : IServiceFacade
{
private WCFService _theRealService = new WCFService();
public Profile ProfileGet(int id)
{
return _theRealService.ProfileGet(id);
}
}
public class Some_Tests()
{
public void Test_Stuff_Whatever()
{
Mock<IServiceFacade> _facade = new Mock<IServiceFacade>();
_facade.SetUp(Whatever.....);
}
}
Your problem is that your service is singleton. The problem of singleton pattern is that it is not testable. You should use Dependency injection to get service.

How to avoid repositories that duplicate code

I have successfully setup a simple mvc application that lists teams. I'm using Ninject to inject the appropriate repository depending on the controller (thanks to stack overflow ;). All looks good, except that the repository code looks exactly the same. And I know that's wrong. So my TeamRepository has two classes (for now).
public class SwimTeamRepository : ITeamRepository<SwimTeam>
{
private readonly Table<SwimTeam> _teamTable;
public SwimTeamRepository(string connectionString)
{
_teamTable = (new DataContext(connectionString).GetTable<SwimTeam>());
}
public IQueryable<SwimTeam> Team
{
get { return _teamTable; }
}
}
public class SoccerTeamRepository : ITeamRepository<SoccerTeam>
{
private readonly Table<SoccerTeam> _teamTable;
public SoccerTeamRepository(string connectionString)
{
_teamTable = (new DataContext(connectionString).GetTable<SoccerTeam>());
}
public IQueryable<SoccerTeam> Team
{
get { return _teamTable; }
}
}
They look exactly the same except for the Class and Table name, so clearly I need to re-factor this. What would be the best approach here? Singleton? Factory Method?
Thanks in advance!
You could use generics:
public interface ITeamRepository<T>
{
}
public class TeamRepository<TTeam> : ITeamRepository<TTeam>
where TTeam : Team
{
private readonly Table<TTeam> _teamTable;
public TeamRepository(string connectionString)
{
_teamTable = (new DataContext(connectionString).GetTable<TTeam>());
}
public IQueryable<TTeam> Team
{
get { return _teamTable; }
}
}
public class Team
{
}
public class SwimTeam : Team
{
}
Then use it like so...
public void MyMethod()
{
var repository = new TeamRepository<SwimTeam>();
}
...and set up your IoC container w/ Ninject like so...
public class MyModule : NinjectModule
{
public override void Load()
{
Bind<ITeamRepository<SwimTeam>>
.To<TeamRepository<SwimTeam>>();
}
}
public void MyMethod()
{
var repository = kernel.Get<ITeamRepository<SwimTeam>>();
}
If you want to get REAL generic and have a single repository for ALL of your mapped classes, you can do something like this:
public interface IRepository
{
IQueryable<T> Get<T>() where T : class, new();
}
public class Repository : IRepository, IDisposable
{
private DataContext _dataContext;
public Repository(string connectionString)
{
_dataContext = new DataContext(connectionString);
}
public IQueryable<T> Get<T>()
where T : class, new()
{
return _dataContext.GetTable<T>().AsQueryable();
}
public void Dispose()
{
if (_dataContext != null)
{
_dataContext.Dispose();
_dataContext = null;
}
}
}
...which you could call like so (after setting up your Ninject container)...
using (var repository = kernel.Get<IRepository>())
{
var swimTeam = repository.Get<SwimTeam>();
}
Since Ninject takes care of the life-cycle management of your objects, you don't HAVE to wrap the repository in a using statement. In fact, you don't want to use a using statement there at all if you plan to use the repository more than once within the scope of its lifetime. Ninject will automatically dispose of it when it's life-cycle ends.
Here's a good article by Rob Conery on using this kind of technique to reduce the friction of using different ORMs.
EDIT by keeg:
I Think
public class TeamRepository<TTeam> : ITeamRepository<TTeam> where TTeam : Team {}
Should be
public class TeamRepository<TTeam> : ITeamRepository<TTeam> where TTeam : class {}
Please correct if I'm wrong.
Is this what you want?
public class TeamRepository : ITeamRepository<T>
{
private readonly Table<T> _teamTable;
public TeamRepository(string connectionString)
{
_teamTable = (new DataContext(connectionString).GetTable<T>());
}
public IQueryable<T> Team
{
get { return _teamTable; }
}
}

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