I want to delete all entities from world. And if a tag or a group is registered for the entity, I want to remove them too. Like there was no such entity at all. It is much like World.delete function, but you should loop on all entities. I can't find a way. And can't believe the designers didn't prepare such functionality for clearing the world from entities. Do I miss something?
There's no default way of deleting all entities from the World - typically this is done by disposing and recreating the world - but it can be easily achieved by adding a custom manager:
public final class EntityTracker extends Manager {
private Bag<Entity> entities = new Bag<Entity>();
#Override
public void added(Entity e) {
entities.add(e);
}
#Override
public void deleted(Entity e) {
entities.remove(e);
}
public void deleteAllEntities() {
for (Entity e : entities)
e.deleteFromWorld();
}
}
In recent versions of artemis-odb it's easier to use the AspectSubscriptionManager:
IntBag entities = world.getAspectSubscriptionManager()
.get(Aspect.all())
.getEntities();
int[] ids = entities.getData();
for (int i = 0, s = entities.size(); s > i; i++) {
world.delete(ids[i]);
}
edit: The above code assumes artemis-odb; I'm not sure whether vanilla artemis' TagManager and GroupManager automatically removes entities upon deletion.
Related
I'm trying to implement a web application using ASP.NET MVC and the Microsoft Unity DI framework. The application needs to support multiple user sessions at the same time, each of them with their own connection to a separate database (but all users using the same DbContext; the database schemas are identical, it's just the data that is different).
Upon a user's log-in, I register the necessary type mappings to the application's Unity container, using a session-based lifetime manager that I found in another question here.
My container is initialized like this:
// Global.asax.cs
public static UnityContainer CurrentUnityContainer { get; set; }
protected void Application_Start()
{
// ...other code...
CurrentUnityContainer = UnityConfig.Initialize();
// misc services - nothing data access related, apart from the fact that they all depend on IRepository<ClientContext>
UnityConfig.RegisterComponents(CurrentUnityContainer);
}
// UnityConfig.cs
public static UnityContainer Initialize()
{
UnityContainer container = new UnityContainer();
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
GlobalConfiguration.Configuration.DependencyResolver = new Unity.WebApi.UnityDependencyResolver(container);
return container;
}
This is the code that's called upon logging in:
// UserController.cs
UnityConfig.RegisterUserDataAccess(MvcApplication.CurrentUnityContainer, UserData.Get(model.AzureUID).CurrentDatabase);
// UnityConfig.cs
public static void RegisterUserDataAccess(IUnityContainer container, string databaseName)
{
container.AddExtension(new DataAccessDependencies(databaseName));
}
// DataAccessDependencies.cs
public class DataAccessDependencies : UnityContainerExtension
{
private readonly string _databaseName;
public DataAccessDependencies(string databaseName)
{
_databaseName = databaseName;
}
protected override void Initialize()
{
IConfigurationBuilder configurationBuilder = Container.Resolve<IConfigurationBuilder>();
Container.RegisterType<ClientContext>(new SessionLifetimeManager(), new InjectionConstructor(configurationBuilder.GetConnectionString(_databaseName)));
Container.RegisterType<IRepository<ClientContext>, RepositoryService<ClientContext>>(new SessionLifetimeManager());
}
}
// SessionLifetimeManager.cs
public class SessionLifetimeManager : LifetimeManager
{
private readonly string _key = Guid.NewGuid().ToString();
public override void RemoveValue(ILifetimeContainer container = null)
{
HttpContext.Current.Session.Remove(_key);
}
public override void SetValue(object newValue, ILifetimeContainer container = null)
{
HttpContext.Current.Session[_key] = newValue;
}
public override object GetValue(ILifetimeContainer container = null)
{
return HttpContext.Current.Session[_key];
}
protected override LifetimeManager OnCreateLifetimeManager()
{
return new SessionLifetimeManager();
}
}
This works fine as long as only one user is logged in at a time. The data is fetched properly, the dashboards work as expected, and everything's just peachy keen.
Then, as soon as a second user logs in, disaster strikes.
The last user to have prompted a call to RegisterUserDataAccess seems to always have "priority"; their data is displayed on the dashboard, and nothing else. Whether this is initiated by a log-in, or through a database access selection in my web application that calls the same method to re-route the user's connection to another database they have permission to access, the last one to draw always imposes their data on all other users of the web application. If I understand correctly, this is a problem the SessionLifetimeManager was supposed to solve - unfortunately, I really can't seem to get it to work.
I sincerely doubt that a simple and common use-case like this - multiple users logged into an MVC application who each are supposed to access their own, separate data - is beyond the abilities of Unity, so obviously, I must be doing something very wrong here. Having spent most of my day searching through depths of the internet I wasn't even sure truly existed, I must, unfortunately, now realize that I am at a total and utter loss here.
Has anyone dealt with this issue before? Has anyone dealt with this use-case before, and if yes, can anyone tell me how to change my approach to make this a little less headache-inducing? I am utterly desperate at this point and am considering rewriting my entire data access methodology just to make it work - not the healthiest mindset for clean and maintainable code.
Many thanks.
the issue seems to originate from your registration call, when registering the same type multiple times with unity, the last registration call wins, in this case, that will be data access object for whoever user logs-in last. Unity will take that as the default registration, and will create instances that have the connection to that user's database.
The SessionLifetimeManager is there to make sure you get only one instance of the objects you resolve under one session.
One option to solve this is to use named registration syntax to register the data-access types under a key that maps to the logged-in user (could be the database name), and on the resolve side, retrieve this user key, and use it resolve the corresponding data access implementation for the user
Thank you, Mohammed. Your answer has put me on the right track - I ended up finally solving this using a RepositoryFactory which is instantiated in an InjectionFactory during registration and returns a repository that always wraps around a ClientContext pointing to the currently logged on user's currently selected database.
// DataAccessDependencies.cs
protected override void Initialize()
{
IConfigurationBuilder configurationBuilder = Container.Resolve<IConfigurationBuilder>();
Container.RegisterType<IRepository<ClientContext>>(new InjectionFactory(c => {
ClientRepositoryFactory repositoryFactory = new ClientRepositoryFactory(configurationBuilder);
return repositoryFactory.GetRepository();
}));
}
// ClientRepositoryFactory.cs
public class ClientRepositoryFactory : IRepositoryFactory<RepositoryService<ClientContext>>
{
private readonly IConfigurationBuilder _configurationBuilder;
public ClientRepositoryFactory(IConfigurationBuilder configurationBuilder)
{
_configurationBuilder = configurationBuilder;
}
public RepositoryService<ClientContext> GetRepository()
{
var connectionString = _configurationBuilder.GetConnectionString(UserData.Current.CurrentPermission);
ClientContext ctx = new ClientContext(connectionString);
RepositoryService<ClientContext> repository = new RepositoryService<ClientContext>(ctx);
return repository;
}
}
// UserData.cs (multiton-singleton-hybrid)
public static UserData Current
{
get
{
var currentAADUID = (string)(HttpContext.Current.Session["currentAADUID"]);
return Get(currentAADUID);
}
}
public static UserData Get(string AADUID)
{
UserData instance;
lock(_instances)
{
if(!_instances.TryGetValue(AADUID, out instance))
{
throw new UserDataNotInitializedException();
}
}
return instance;
}
public static UserData Current
{
get
{
var currentAADUID = (string)(HttpContext.Current.Session["currentAADUID"]);
return Get(currentAADUID);
}
}
public static UserData Get(string AADUID)
{
UserData instance;
lock(_instances)
{
if(!_instances.TryGetValue(AADUID, out instance))
{
throw new UserDataNotInitializedException();
}
}
return instance;
}
After watching the "Enhancements to Code First Migrations: Using HasDefaultSchema and ContextKey for Multiple Model Support" section of Julie Lerman's PluralSite video, "Entity Framework 6: Ninija Edition-What's New in EF 6" (https://app.pluralsight.com/library/courses/entity-framework-6-ninja-edition-whats-new/table-of-contents), it seems there is a way to run multiple schemas under a single database in Entity Framwork 6 using Code First Migrations...
However, based on the video you still need to these package manager commands for each project that houses a separate context:
1. enable-migrations
2. add-migration [MIGRATION NAME]
3. update-database
This is fine and good if you actually care about maintaining migrations going forward, which is not a concern of mine.
What I'd like to do is have each of my Context's initializers set to DropCreateDatabaseAlways, and when I start up my client app (in this case, an MVC site), code first will create the database for the first context used, create the tables in with the correct schema for that context, and then create the tables for the rest of the contexts with the correct schema.
I don't mind if the whole database is dropped and recreated every time I hit F5.
What is happening now is the last context that is accessed in the client app is the only context tables that are created in the database... any contexts being accessed before the last get their tables blown away.
I am currently using two contexts, a Billing context and a Shipping context.
Here is my code:
My client app is an MVC website, and its HomeController's Index method looks like this:
public ActionResult Index()
{
List<Shipping.Customer>
List<Billing.Customer> billingCustomers;
using (var shippingContext = new Shipping.ShippingContext())
{
shippingCustomers = shippingContext.Customers.ToList();
}
using (var billingContext = new Billing.BillingContext())
{
billingCustomers = billingContext.Customers.ToList();
}
}
Here is my DbMigrationsConfigurationClass and ShippingContext class for the Shipping Context:
internal sealed class Configuration : DbMigrationsConfiguration<ShippingContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(ShippingContext context)
{
}
}
public class ShippingContext : DbContext
{
public ShippingContext() : base("MultipleModelDb")
{
}
static ShippingContext()
{
Database.SetInitializer(new ShippingContextInitializer());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.HasDefaultSchema("Shipping");
base.OnModelCreating(modelBuilder);
}
public DbSet<Customer> Customers { get; set; }
class ShippingContextInitializer : DropCreateDatabaseAlways<ShippingContext>
{
}
}
Likewise, here is the DbMigrationConfiguration class for the Billing Context and the BillingContext class:
internal sealed class Configuration : DbMigrationsConfiguration<BillingContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(BillingContext context)
{
}
}
public class BillingContext : DbContext
{
public BillingContext() : base("MultipleModelDb")
{
}
static BillingContext()
{
Database.SetInitializer(new BillingContextInitializer());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.HasDefaultSchema("Billing");
base.OnModelCreating(modelBuilder);
}
public DbSet<Customer> Customers { get; set; }
class BillingContextInitializer : DropCreateDatabaseAlways<BillingContext>
{
}
}
based on the order that the contexts are being called in the controller's action method, whichever context is accessed last is the only context that is created... the other context is wiped out.
I feel like what I'm trying to do is very simple, yet code first migrations, as well as trying to "shoehorn" Entity Framework to represent multiple contexts as separate schemas in the same physical database seems a bit "hacky"...
I'm not that versed with migrations to begin with, so what I'm trying to do might not make any sense at all.
Any feedback would be helpful.
Thanks,
Mike
I'm using EF 5 with Web Forms (ASP.NET 4.5), with the "one DbContext instance per request" approach.
But this situation is a bit complicated: I have a multi-step create/edit screen, and I store the current entity in Session, then I manipulate it and in the final step, I commit it to the Database.
Creating a new instance was fine, but I can't for the life of me edit an existing entity... Because it's another request, my original DbContext instance was lost and when I attach it to a new one, I get the An entity object cannot be referenced by multiple instances of IEntityChangeTracker error.
My code is far too complex to post here, but I'll try and summarize it accurately:
My DbContext:
public class AppContext : DbContext
{
// DbSet declarations...
public static AppContext Current {
get { var context = HttpContext.Current.Items["Contexts.AppContext"] as AppContext;
if (context == null)
{
context = new AppContext();
HttpContext.Current.Items["Contexts.AppContext"] = context;
}
return context;
}
}
}
An example of what the page code looks like:
protected void Page_Load(object sender, EventArgs e)
{
int? id = null; // After this, I try to get it from the QueryString, parse it, etc.. Omitted for sake of brevity
// If I have an ID, it means I'm editing...
Session["Product"] = id.HasValue ? new Product() : AppContext.Current.Products.Find(id));
MethodToPopulateFields(); // Internally, it uses the Session variable
}
protected void Step1(){ // through n
// Manipulates the Session["Product"] based on page input...
}
protected void Save(){
var product = Session["Product"] as Product;
if(product.ID == 0)
product = AppContext.Current.Products.Add(product);
// throws an exception:
// AppContext.Current.Entry(product).State = EntityState.Modified;
// this too:
// AppContext.Products.Attach(product);
AppContext.Current.SaveChanges();
}
I know I can get the old entity from the database, update it manually and save, all in the last step, but I really don't want to do that...
Thank you.
Try calling
AppContext.Current.Entry(product).State = EntityState.Detached;
in the first method.
I'm coding a business layer for an ASP.NET application. I've created database methods in my BLL as static. I've created public static Func variables to be compiled and used in several different methods, like this:
namespace BLL
public class User
{
public static Func<Context, variable, result> selectUser;
private static void CompileQuery()
{
if(selectUser == null)
{
selectUser = CompiledQuery.Compile......
}
}
public static UserClass Select(int id)
{
CompileQuery();
//uses selectUser
}
public static SomethingElse DoSomethingElse()
{
CompileQuery();
//also uses selectUser
}
}
It'll be used in ASP.NET layer like this:
using BLL;
private void AddUser()
{
UserClass user = User.Select(id);
}
My question is, since static variables are not thread-safe, is this a bad design decision? I'm thinking of either implementing a locking mechanism, which makes me think if it'd slow down the application, or using instantiated class approach which makes me wonder if query compiling would be beneficial. I'd appreciate any advice on this.
It should at least be read-only - and initialized on type load, like this:
public static readonly Func<Context, variable, result> selectUser =
CompileQuery(); // Or inline this...
private static Func<Context, variable, result> CompileQuery()
{
return CompiledQuery.Compile(...);
}
I'd probably make it a property myself, but otherwise it should be okay. Delegates themselves are immutable and threadsafe, so that shouldn't be a problem.
Doing it on type initialization means you don't need to worry about locking: the CLR guarantees that a type initializer is executed once and only once.
Being new to RhinoMocks and Unit Testing, I have come accross an issue that I cannot seem to find a resolution to (no matter how much documentation I read).
The issue is this: I have created an Interface that exposes 5 Events (to be used for a view in ASP.NET and the MVP Supervisory Controller pattern..... I know, I should be using MVC, but that's a whole other issue). Anyway, I want to test that when a certain event fires on the view, we'll call it "IsLoaded", that a method inside of my Presenter is called and, using Dependency Injection, a value is returned from the Dependency and set to the view. Here is where the problem starts: when I use Expect.Call(Dependency.GetInfo()).Return(SomeList), the Call never executes (without the mock.ReplayAll() method being invoked). Well, when I invoke the ReplayAll method, I get ExpectationExceptions because of the Subscription by the Presenter object to the other Events exposed by the View Interface.
So, for me to test that IView.IsLoaded has fired, I want to verify that IView.ListOfSomething has been updated to match the list I passed in via the Expect.Call(). However, when I set the expectation, the other Event subscriptions (which occur straight out of the constructor for the Presenter) fail the #0 Expectations of the test. What I get is, view.Save += this.SaveNewList tosses up a RhinoMocks ExpectationViolationException.
My million dollar question is this: Is it necessary I set expectations for ALL of my events (via [Setup]), or is there something that I'm missing/not understanding about how Unit Testing or RhinoMocks works?
Please bear in mind I am extremely new to Unit Testing, and therefore RhinoMocks. If it appears I don't know what I'm talking about, please feel free to point that out.
I'm working on a project where we used MVP and rhino mocks as well. What we did was simply expect all event subscriptions in every test.
private void SetupDefaultExpectations()
{
_mockView.Initializing += null; LastCall.IgnoreArguments();
_mockView.SavingChanges += null; LastCall.IgnoreArguments();
}
Then we built a extension method on IMockedObject (from RhinoMocks) to trigger events in the unit tests and un-wrap exceptions so that they can be expected in the standard NUnit way.
static class IMockedObjectExtension
{
public static void RaiseEvent(this IMockedObject mockView, string eventName, EventArgs args)
{
EventRaiser eventraiser = new EventRaiser(mockView, eventName);
try
{
eventraiser.Raise(mockView, args);
}
catch (TargetInvocationException ex)
{
throw ex.InnerException;
}
}
public static void RaiseEvent(this IMockedObject mockView, string eventName)
{
RaiseEvent(mockView, eventName, EventArgs.Empty);
}
}
This could then be used from the unit test like this
using(_mocks.Record())
{
Expect.Call(dependency.GetInfo()).Return(someList);
}
using(_mocks.Playback())
{
Presenter presenter = new Presenter(_mockView, dependency);
(_mockView as IMockedObject).RaiseEvent("SavingChanges");
}
To eliminate duplication between presenter tests we have refactored this to a BasePresenterTest base class which sets up this basic structure for all presenter tests and exposes helper methods to the sub class.
public abstract class BasePresenterTest<VIEW> where VIEW : IBaseView
{
protected MockRepository _mocks;
protected VIEW View { get; private set; }
protected abstract void SetUp();
protected abstract void TearDown();
protected abstract void SetupDefaultExpectations();
[SetUp]
public virtual void BaseSetUp()
{
_mocks = new MockRepository();
View = _mocks.CreateMock<VIEW>();
SetUp();
}
[TearDown]
public virtual void BaseTearDown()
{
TearDown();
View = null;
_mocks = null;
}
protected virtual void BaseSetupDefaultExpectations()
{
//Setup default expectations that are general for all views
SetupDefaultExpectations();
}
protected virtual IDisposable Record()
{
IDisposable mocksRecordState = _mocks.Record();
BaseSetupDefaultExpectations();
return mocksRecordState;
}
protected virtual IDisposable Playback()
{
return _mocks.Playback();
}
protected void RaiseEventOnView(string eventName)
{
(View as IMockedObject).RaiseEvent(eventName);
}
}
This eliminates alot of code from the tests in our project.
We still use a old version of RhinoMocks but I will try to update this once we move to a later version.