The ms doc says it should exist a Listeners property in Debug.Diagnostics.Debug in netstandard 2, but this is not the case in a real project. The Listeners property is undefined.
I tryed adding the System.Diagnostics.Debug nuget with no luck.
Any clue?
When you try to navigate to the page for Debug.Listeners Property for .NET Standard 2 the page clearly states:
The requested page is not available for .NET Standard 2.0. You have been redirected to the newest product version this page is available for.
Diving in a bit deeper, you can find all APIs implemented in .NET standard 2 on their github. Here you can see that the public static class Debug doesn't have a Listeners property.
However, the article on the Debug.Listeners Property I referred to above also states
The Listeners collection is shared by both the Debug and the Trace classes; adding a trace listener to either class adds the listener to both.
The .NET standard API's also learns us that the public sealed class Trace does implement public static TraceListenerCollection Listeners { get; }. This would lead me to believe you can access the Listeners through the Trace class.
Related
I want to create a controller based JavaFX GUI consisting of multiple controllers.
The task I can't accomplish is to pass parameters from one Scene to another AND back.
Or in other words:
The MainController loads SubController's fxml, passes an object to SubController, switches the scene. There shall not be two open windows.
After it's work is done, the SubController shall then switch the scene back to the MainController and pass some object back.
This is where I fail.
This question is very similar to this one but still unanswered. Passing Parameters JavaFX FXML
It was also mentioned in the comments:
"This work when you pass parameter from first controller to second but how to pass parameter from second to first controller,i mean after first.fxml was loaded.
– Xlint Xms Sep 18 '17 at 23:15"
I used the first approach in the top answer of that thread.
Does anyone have a clue how to achieve this without external libs?
There are numerous ways to do this.
Here is one solution, which passes a Consumer to another controller. The other controller can invoke the consumer to accept the result once it has completed its work. The sample is based on the example code from an answer to the question that you linked.
public Stage showCustomerDialog(Customer customer) {
FXMLLoader loader = new FXMLLoader(
getClass().getResource(
"customerDialog.fxml"
)
);
Stage stage = new Stage(StageStyle.DECORATED);
stage.setScene(
new Scene(
(Pane) loader.load()
)
);
Consumer<CustomerInteractionResult> onComplete = result -> {
// update main screen based upon result.
};
CustomerDialogController controller =
loader.<CustomerDialogController>getController();
controller.initData(customer, onComplete);
stage.show();
return stage;
}
...
class CustomerDialogController() {
#FXML private Label customerName;
private Consumer<CustomerInteractionResult> onComplete
void initialize() {}
void initData(Customer customer, Consumer<CustomerInteractionResult> onComplete) {
customerName.setText(customer.getName());
this.onComplete = onComplete;
}
#FXML
void onSomeInteractionLikeCloseDialog(ActionEvent event) {
onComplete.accept(new CustomerInteractionResult(someDataGatheredByDialog));
}
}
Another way to do this is to add a result property to the controller of the dialog screen and interested invokers could listen to or retrieve the result property. A result property is how the in-built JavaFX dialogs work, so you would be essentially imitating some of that functionality.
If you have a lot of this passing back and forth stuff going on, a shared dependency injection model based on something like Gluon Ignite, might assist you.
I've used AfterBurner.fx for dependency injection, which is very slick and powerful as long as you follow the conventions. It's not necessarily an external lib if you just copy the 3 classes into your structure. Although you do need the javax Inject jar, so I guess it is an eternal reference.
Alternately, if you have a central "screen" from which most of your application branches out you could use property binding probably within a singleton pattern. There are some good articles on using singleton in JavaFX, like this one. I did that for a small application that works really great, but defining all of those bindings can get out of hand if there are a lot of properties.
To pass data back, the best approach is probably to fire custom Events, which the parent controller subscribes to with Node::addEventHandler. See How to emit and handle custom events? for context.
In complex cases when the two controllers have no reference to each other, a Event Bus as #jewelsea mentioned is the superior option.
For overall architecture, this Reddit comment provides some good detail: https://www.reddit.com/r/java/comments/7c4vhv/are_there_any_canonical_javafx_design_patterns/dpnsedh/
Can someone please help me understand several things?
Do I still have to register PerRequestModule to use
LifeStylePerWebRequest? I use Castle.Windsor 3.2.0.0 and it seems
everything works without this module. I definetly remember that
there was an exception before that tells me "You forget to register
this module".
What "objects tracked by release policy" really
means? I use several Components with LifeStyleTransient but when I
Resolve one I get it in "objects tracked by release policy"
property, when I Resolve others I don't get them there.
How can I check the actual objects stored inside the container (and their
number)?
1) I guess since version 3.x PerRequestModule will be automatically registered by windsor.
2) An object will be tracked by windsor only if needed(for ex if its lifestyle is Transient and it implements IDisposable interface).
3) You can run unit tests checking for handlers or manually set a debug point once you registered all components and navigate with VS viewer container object: it has a property that lists all registered components.
I'm using NServiceBus (3.2.2), RavenDB (1.2.2017-Unstable) and Windsor (3.0.0.4001) in an MVC 4 project.
I have a IHandleMessages class that handles 3 different messages, and that needs an IDocumentSession, and therefore defines a property such as:
public IDocumentSession DocumentSession { get; set; }
I've copied the RavenDbUnitOfWork implementation from NServiceBus' website
I've registered IDocumentStore, IDocumentSession and IManageUnitsOfWork in my Windsor container as follow:
container.Register(
Component
.For<IManageUnitsOfWork>()
.ImplementedBy<RavenUnitOfWork>()
.LifestyleTransient()
);
container.Register(
Component
.For<IDocumentStore>()
.UsingFactoryMethod(k => DocumentStoreHolder.DocumentStore)
.LifestyleSingleton(),
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleTransient()
);
NServiceBus is configured to use my container:
Configure.With()
.CastleWindsorBuilder(container);
I'm encountering the problem that the UnitOfWork and the message handler receive different instances of the DocumentSession. This means that objects stored in the session in the message handler are not saved, since SaveChanges() is called on a different DocumentSession.
Removing the Transient lifestyle causes different kind of problems, that result in concurrency/conflicts when updating objects from RavenDb, since (probably) the message handler keeps getting the same instance of the DocumentSession, which holds a cached version of the updated object.
Update:
As suggested, I've tried changing the registration of the IDocumentSession in Windsor, to the Scope lifestyle, like this:
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleScope()
This causes exceptions when the container tries to resolve the MVC Controller, saying that the scope was not found, and asking if I forgot to call BeginScope().
You need to have a scope of Per Message, not transient or singleton.
I am assuming that your mvc controller has a direct dependency on the IDocumentStore. You need to call container.BeginScope() before each request from the web. You can either do this as an action filter attribute http://msdn.microsoft.com/en-us/library/system.web.mvc.actionfilterattribute.aspx or as an AOP aspect on the controller itself http://cangencer.wordpress.com/2011/06/02/asp-net-mvc-3-aspect-oriented-programming-with-castle-interceptors/.
The issue is you need different lifestyles when using nservicebus in an asp.net mvc website when sharing the IDocumentSession in the same container.
For ASP.NET MVC you need a PerWebRequest lifestyle and for NServiceBus you need the Scoped lifestyle.
To do that i've used the hybrid lifestyle code in the castle contrib project:
https://github.com/castleprojectcontrib/Castle.Windsor.Lifestyles/tree/master/Castle.Windsor.Lifestyles
When calling from an ASP.NET context, it uses the WebRequestScopeAccessor. For NServicebus you need the LifetimeScopeAccessor. This is not in the contrib project, but is easy to add:
public class HybridPerWebRequestLifetimeScopeScopeAccessor : HybridPerWebRequestScopeAccessor
{
public HybridPerWebRequestLifetimeScopeScopeAccessor()
: base(new LifetimeScopeAccessor())
{
}
}
And in your registration code you need something like:
container.Register(Component.For<IDocumentSession>().LifestyleScoped<HybridPerWebRequestLifetimeScopeScopeAccessor>().UsingFactoryMethod(() => RavenDbManager.DocumentStore.OpenSession()));
And here's an implementation for Rhino Service Bus i used before switching to nservicebus:
https://gist.github.com/4655544
Basically, I want to modify the constructor of the Object
class. Since every class extends Object, I hope whenever any
object of any class is instantiated, the modified function will
be called.
So I did this :
Object.prototype.constructor = function (){
trace("it was called;");
};
and put a breakpoint on the trace statement.
But it didn't stop there.
The trace statement did not get executed also.
Any solutions/suggestions?
In which context are you coding?
If you're using the Flex Compiler MXMLC (default, if you're in FlashBuilder), than you could add the compiler option -es. This should make AS3 feel more like AS2 and JS and support the prototype chain inheritance.
-compiler.es alias -es
"use the ECMAScript edition 3 prototype based object model to allow dynamic overriding of prototype properties. In the prototype based object model built-in functions are implemented as dynamic properties of prototype objects. (advanced)"
I don't know, if this plays well with all the extensions Adobe added to the ECMA Script standard, like packages, namespaces and classes. But you could give it a try.
I don't think it's possible in AS-3, but it was in AS-2.
In a multilayer application (ASP MVC: UI project, DAL project) i registered in web.config the components.
Now i have this problem: Unit of Work pattern has do be implemented and i need to get the current instance of a particular service. The registration of the services happened in the UI project, but i need to get the current instance of this service in the DAL project. How do i get this reference?
In the UI project i already needed a way to get something resolved:
container = new WindsorContainer(
new XmlInterpreter(new ConfigResource("castle"))
);
personRepository= container.Resolve<IPersonRepository>();
Would it be OK to use the same technique in the DAL project? If yes, should i write the configuration in a separate file, so that it can be accessed by all the layers(projects)?
Sorry for this (i think) naive question but it's my first project using Castle and i think i don't understand the big picture of it!
Code snippet would help a lot.
Thanks in advance!
In a nutshell: one container instance per application, one container configuration that has all the components you need for the application. If you need a service in your DAL, inject the appropriate service interface in your DAL class via constructor (if the dependency is required) or setter (if the dependency is optional).
Try really hard to avoid using a static IoC gateway, it hides the true dependencies of a component and it hampers testability.
See these related questions:
Usage of IoC Containers; specifically Windsor
Is it correct to have many Castle Windsor containers per application if those containers belong to different tiers?
Have a look at this article. It shows you how to write a static class that performs dependency resolution using Castle Windsor. You should consider putting this class in a separate project that can be referenced from both your UI and DAL projects to allow code reuse. As the article explains, your class should provide a bootstrapper facility that initializes your IoC container. In your case, this would look like:
public static class IoC
{
private WindsorContainer _container;
public static void Initialize()
{
_container = new WindsorContainer(
new XmlInterpreter(new ConfigResource("castle"))
);
}
}
The bootstrapper would be invoked from the application startup event in your UI projects Global.asax file.
The other methods for obtaining instances of objects from the container would be as per the article.