Asp.net core rc1, dbcontext connection is closed in IStringLocalizer GetString method - entity-framework

Question

Asp.net core rc1, dbcontext connection is closed in IStringLocalizer GetString method. Happening only when VS2015 is on Debug mode and only once at start up.
I am using Autofac DI, but same issue (without autofac) using the buildin DI.
When I am running the App in debug mode and only at start up, producing the following error. When I refresh the browser all fine, no errors. If I run the App without debugging, no errors, everything runs normally.
Something's wrong with the debugging threat and the DI? Any ideas?
Error on browser:
A database operation failed while processing the request.
InvalidOperationException: ExecuteReader requires an open and
available Connection. The connection's current state is closed.
Output window:
Microsoft.Data.Entity.Storage.Internal.RelationalCommandBuilderFactory: Information: Executed DbCommand (55ms) [Parameters=[#___cultureName_0='?', #__name_1='?'], CommandType='Text', CommandTimeout='30']
SELECT TOP(1) [l].[CultureId], [l].[Name], [l].[Value]
FROM [UIResources] AS [l]
WHERE ([l].[CultureId] = #___cultureName_0) AND ([l].[Name] = #__name_1)
Microsoft.Data.Entity.Query.Internal.QueryCompiler: Error: An exception occurred in the database while iterating the results of a query.
System.NullReferenceException: Not Specified object reference to an instance object.
σε System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
σε System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
σε System.Data.SqlClient.SqlConnection.Open()
σε Microsoft.Data.Entity.Storage.RelationalConnection.Open()
σε Microsoft.Data.Entity.Query.Internal.QueryingEnumerable.Enumerator.MoveNext()
σε System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
σε System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
σε lambda_method(Closure , QueryContext )
σε Microsoft.Data.Entity.Query.Internal.QueryCompiler.<>c__DisplayClass18_1`1.<CompileQuery>b__1(QueryContext qc)
Microsoft.Data.Entity.Query.Internal.QueryCompiler: Error: An exception occurred in the database while iterating the results of a query.
System.InvalidOperationException: ExecuteReader requires an open and available Connection. The connection's current state is closed.
at System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite)
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
at Microsoft.Data.Entity.Storage.Internal.RelationalCommand.<>c__DisplayClass17_0.<ExecuteReader>b__0(DbCommand cmd, IRelationalConnection con)
at Microsoft.Data.Entity.Storage.Internal.RelationalCommand.Execute[T](IRelationalConnection connection, Func`3 action, String executeMethod, Boolean openConnection, Boolean closeConnection)
at Microsoft.Data.Entity.Storage.Internal.RelationalCommand.ExecuteReader(IRelationalConnection connection, Boolean manageConnection)
at Microsoft.Data.Entity.Query.Internal.QueryingEnumerable.Enumerator.MoveNext()
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
at lambda_method(Closure , QueryContext )
at Microsoft.Data.Entity.Query.Internal.QueryCompiler.<>c__DisplayClass18_1`1.<CompileQuery>b__1(QueryContext qc)
Exception thrown: 'System.NullReferenceException' in EntityFramework.Core.dll
Exception thrown: 'System.InvalidOperationException' in EntityFramework.Core.dll
This is my startup:
public IServiceProvider ConfigureServices(IServiceCollection services)
{
// Add framework services.
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
services.AddIdentity<ApplicationUser, ApplicationRole>()
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
services.AddMvc().AddViewLocalization();
services.AddMvc().AddDataAnnotationsLocalization();
services.AddLocalization();
// Create the Autofac container builder.
var builder = new ContainerBuilder();
// Populate the services from the collection.
// This have to come First.
builder.Populate(services);
// Register dependencies.
builder.RegisterType<AuthMessageSender>().As<IEmailSender>().InstancePerLifetimeScope();
builder.RegisterType<AuthMessageSender>().As<ISmsSender>().InstancePerLifetimeScope();
builder.RegisterType<DataInitializer>().As<IDataInitializer>().InstancePerLifetimeScope();
builder.RegisterType<CultureHelper>().As<ICultureHelper>().InstancePerLifetimeScope();
builder.RegisterType<RouteRequestCultureProvider>().InstancePerLifetimeScope();
builder.RegisterType<CultureActionFilter>().InstancePerLifetimeScope();
builder.RegisterType<DbStringLocalizerFactory>().As<IStringLocalizerFactory>().InstancePerLifetimeScope();
// DbStringLocalizer registers with InstancePerDependency,
// because localization requires a new instance of IStringLocalizer created in the IStringLocalizerFactory.
builder.RegisterType<DbStringLocalizer>().As<IStringLocalizer>().InstancePerDependency();
// Build the container.
var container = builder.Build();
// Return the IServiceProvider resolved from the container.
return container.Resolve<IServiceProvider>();
}
This is Localization implementation:
public class DbStringLocalizerFactory : IStringLocalizerFactory
{
private IServiceProvider _serviceProvider;
public DbStringLocalizerFactory(IServiceProvider serviceProvider)
{
_serviceProvider = serviceProvider;
}
public IStringLocalizer Create(Type resourceSource)
{
return _serviceProvider.GetService<IStringLocalizer>();
}
public IStringLocalizer Create(string baseName, string location)
{
return _serviceProvider.GetService<IStringLocalizer>();
}
}
public class DbStringLocalizer : IStringLocalizer
{
private ApplicationDbContext _db;
private string _cultureName;
public DbStringLocalizer(ApplicationDbContext db)
: this(db, CultureInfo.CurrentCulture)
{
}
public DbStringLocalizer(ApplicationDbContext db, CultureInfo cultureInfo)
{
_db = db;
_cultureName = cultureInfo.Name;
}
public LocalizedString this[string name]
{
get
{
var value = GetString(name);
return new LocalizedString(name, value ?? name, resourceNotFound: value == null);
}
}
public LocalizedString this[string name, params object[] arguments]
{
get
{
var format = GetString(name);
var value = string.Format(format ?? name, arguments);
return new LocalizedString(name, value, resourceNotFound: format == null);
}
}
private string GetString(string name)
{
//try
//{
var query = _db.UIResources.Where(l => l.CultureId == _cultureName);
var value = query.FirstOrDefault(l => l.Name == name);
return value?.Value;
//}
//catch
//{
// return null;
//}
}
public IEnumerable<LocalizedString> GetAllStrings(bool includeAncestorCultures)
{
return _db.UIResources.Where(l => l.CultureId == _cultureName)
.Select(l => new LocalizedString(l.Name, l.Value, true));
}
public IStringLocalizer WithCulture(CultureInfo culture)
{
return new DbStringLocalizer(_db, culture);
}
}

Answer 1

The IDataInitializer registration as scoped service in
builder.RegisterType<DataInitializer>().As<IDataInitializer>().InstancePerLifetimeScope();
seems odd, as a data initializer is expected to be called only once, when the application starts to ensure the database is created and filled with data required to run the application or after an update.
I suspect you dispose the scoped db context somewhere inside your DataInitializer class, so it becomes unavailable during your request because your IoC container will always return the same instance for the duration of the request.