Does anyone have an example of the new abstract method CreateContainerExtension that is in Prism.Wpf 7.1.0.172-pre? We are using the common service locator and have essentially bypassed IOC in Prism because we need to resolve things before the Bootstrapper has run.
You should remember that Prism is open source and the source code is in itself a form of documentation.
If you're using the classic Bootstrapper, you'll notice that it has been deprecated in favor of PrismApplication. Since your question is extremely vague as to what container you're even trying to use, it's impossible to tell exactly which Container Extension to use, but I will provide an example using Unity for your reference.
Whether you look at the UnityBootstraper or the Unity PrismApplication, you'll see that it simply returns an instance of the UnityContainerExtension.
protected override IContainerExtension CreateContainerExtension()
{
return new UnityContainerExtension();
}
Related
I am attempting to update a Prism 8.1 app to use Shiny v2.
In trying to turn one of my services into a Job I keep getting a container resolution error (using Unity). I am not sure what the pattern is for registering platform implementations of services. The Job has a service that is from my platform project but at the time the services.RegisterJob() is called I guess the platform initializer has not run.
Can someone post an example of how you are supposed to register platform implementations with Shiny?
Well, I'm not sure if this is the intended design but I solved the platform services this way.
I added a constructor parameter to my ShinyStartup like this:
public Startup(IPlatformInitializer platformInitializer) : base(PrismContainerExtension.Current)
{
_platformInitializer = platformInitializer;
}
and then in my AppDelegate I used this:
Shiny.ShinyHost.Init(new Shiny.ApplePlatform(), new Startup(new iOSInitializer()));
Where iOSInitializer is my Prism IPlatformInitializer.
Then in Startup I added:
protected override void RegisterServices(IContainerRegistry containerRegistry)
{
_platformInitializer.RegisterTypes(containerRegistry);
...
}
As far as the IJob not resolving dependencies when using RegisterJob, I moved job registration to App.OnStart using IJobManager.Register and it works. Also not sure if this is the intended design.
I did all my container wire up before calling RegisterJob and it still failed to resolve so there must be something under the covers that is happening in the Prism+Shiny world.
I always got problems with the private variable declaration.
For example FlatFileItemWrite. I would like to extend these class and overwrite the 'doRead' method. This would not work because some of the used variables are declared private. This leads to copying the complete code in an own class for overwriting one method.
Sometime even this does not work because the class extends an other class which has variables declared visible only for the same package. Then you need to copy this class also.
Then I will miss updates in the original classes with new versions. So would it not be better to use protected instead?
I can imaging only a very few reasons to use private instead of protected. For my own programs this is not an issue, I could change it on demand. But for a framework it is a pain.
with kind regards
Torsten
If something is declared private within the Spring framework (or any framework for that matter), it's not considered part of the public API. Because of that, you really shouldn't be looking to work with it directly. Doing so really means you're forking the framework and risking not being able to upgrade seamlessly.
As the project lead for Spring Batch, I'd be interested in hearing what you had to do with the FlatFileItemWriter that required you to change things that are marked private.
If the idea behind the framework was to override or extend these methods, they should have been written as being public. (be careful if a framework does not provide these methods or properties as public, since it might depend on them working in a specific way. this would be the primary reason for them being private i can think of. the secondary being that they don't matter outside that class.)
In some cases, you might not need to copy the entire class, but simply inheriting or extending it might be enough.
I'm also looking to extend certain ItemReaders/ItemWriters to support decryption/encryption on i/o. For example, I'd like to extend StaxEventItemReaderStaxEventItemReader in order to read an encrypted stream from the resource, but the FragmentEventReader is private, so I'm unable to wrap its XMLEventReader's InputStream in a decrypter.
I faced the same issue with FlatFileItemWriter.
I've decided to use custom template engine with Spring MVC framework.
my templates implemented in java and have method for rendering into String:
public String render(Map context);
how to configure spring to make them available in Controller beans as views, for example like:
ModelAndView modelAndView = new ModelAndView("activationPage"); // - view name which will actually be java class name reference.
modelAndView.addObject("validationResult", validationResult);
return modelAndView;
Model will be passed as context in code connecting spring and my template engine.
You need to implement org.springframework.web.servlet.View (which should be easy, you already have something very similar to the render method it needs), as well as org.springframework.web.servlet.ViewResolver, which maps the view names (e.g. "activationPage") on your custom views.
Once you have that, drop a bean of your ViewResolver class into the context, and (unless you've done something else that gets in the way) it should automatically be picked up by Spring and should just work. if you have other ViewResolvers already in there, they may get into a fight over who gets to resolve the view, in which case ask a new question.
Hi I am the author of Rythm template engine, about half year ago I am having the same requirement like you. What I did is to read the source code of Velocity and Freemarker view of SpringFramework. And then create the Rythm view for spring following their approach.
It's easy to follow something that is already there, and it makes your implementation in good quality to follow the official module. Good luck on you :-)
all. I am getting started with NServiceBus and have a pretty good handle on the basics thanks to Pluralsight and the internet. I have an stock MVC 4 project and I have setup dependency injection for my controllers (thanks to this blog post).
Here is how I have my bus setup in Global.asax:
_bus = Configure.With()
.DefaultBuilder()
.ForMVC()
.Log4Net()
.XmlSerializer()
.MsmqTransport()
.UnicastBus()
.SendOnly();
I am assigning it to a local private variable because I need access to the bus in Global so I can do some stuff on Session_End. However, when I run, I get the following error:
The requested service 'System.Web.Mvc.IControllerFactory' has not been
registered. To avoid this exception, either register a component to
provide the service, check for service registration using
IsRegistered(), or use the ResolveOptional() method to resolve an
optional dependency.
According to my stack trace, the failure point is when Autofac tries to resolve the type. For the sake of sanity, I removed the private variable and used just the Configure statement, same thing. I also have Ninject wired up in this app because that is my IoC of choice. Thinking that it was interfering with Autofac in some way, I removed Ninject from the equation, still not working.
So my question is, what am I doing wrong? Am I missing something? This is my first time with NServiceBus, but from everything I've seen, this should just work. Any info would be super helpful. Thanks.
Have a look at our MVC4 sample (this is running against v4, the next major release):
https://github.com/NServiceBus/NServiceBus/tree/develop/Samples/Messaging.Msmq/MyWebClient
I found the solution from your code, John! Here was my issue. This is what I had in my Dependency Resolver Adapter:
public object GetService(Type serviceType)
{
_builder.Build(serviceType);
}
What I needed to do was what you did in your MVC4 example:
public object GetService(Type serviceType)
{
return (Configure.Instance.Configurer.HasComponent(serviceType)) ? _builder.Build(serviceType) : null;
}
Once I did that, it all sorted itself out. Thanks again for the help!
I'm trying to get myself familiar with MVC3 and autofac but I've encountered small problem that I'm having trouble resolving.
I am using autofac integrated with MVC3 and all works well, pages are loading correctly, dependencies are being injected and that's cool. What's bugging me is how to use autofac's Container or MVC's DependencyResover in class library project.
I'm trying to create static class that will help me handle domain events. I simply want to be able to call the method with event parameter and everything should be handeled by this class. Here is code:
public static IContainer Container { get; set; }
public static void Raise<T>(T e) where T : IDomainEvent
{
foreach (var eventHandler in DomainEventManager.Container.Resolve<IEnumerable<EventHandlers.Handles<T>>>())
{
eventHandler.Handle(e);
}
}
As you can see it's pretty straightforward and everything would work great if it wasn't MVC approach. Some of my dependencies are registeres as InstancePerHttpRequest (NHibernate' session), while other are registered as InstancePerDependency or SingleInstance. Thus when I try to use container created in my UI project, I get exception that there is no httpRequest tag available.
How can i reuse the Container created in web project to get access to all of it's features, including InstancePerHttpRequest and httpRequest tag?
Or maybe there is other solution to my problem? I was thinking about using delegate function to obtain event handlers, but I cannot (can I?) create generic delegate that I would not need to initialize with concrete type at time of assignment.
Why I want to do this using static class is basically every entity and aggregate or service needs to be able to raise domain event. Injecting EventManager into every one of these would be troublesome and static class is exactly what would resolve all my problems.
If anyone could help me get my head around it I would be grateful.
Cheers, Pako
You shouldn't be referencing your container directly from your app code. This looks like the Service Locator anti-pattern. The correct action is to pass your objects the services they need to do their jobs, usually done through constructor parameters. BUT... if you are going to insist on depending on a global static, then at least model EventManager as a singleton, such that usage would look like:
EventManager.Current.Raise<SomeEvent>(someObject);
and then you can set EventManager.Current equal to a properly constructed instance when your app is initialized.