ModuleManger, why no "UnloadModule(...)"?

[angelotrivelli]

I am new to both PRISM and Unity, this is just a basic conceptual question.

It looks like Modules are intended to be a "plug-in" mechanism. You can create a dll and then load it, on demand, any time after your application has started and even after it has been running for a while. In the docs it shows how I can configure a Module to be "OnDemand", for example...

protected override void ConfigureModuleCatalog()
{
    . . .
    Type moduleCType = typeof(ModuleC);
    this.ModuleCatalog.AddModule(new ModuleInfo()
    {
        ModuleName = moduleCType.Name,
        ModuleType = moduleCType.AssemblyQualifiedName,
        InitializationMode = InitializationMode.OnDemand
    });
    . . .
}

Once a module has been added as OnDemand to the ModuleCatalog, it can actually be loaded through the ModuleManager like this moduleManager.LoadModule("ModuleC");

Inside the Module class definition you may override a "RegisterTypes" method which gives you access to the DI Container Registry...

protected override void RegisterTypes(IContainerRegistry containerRegistry)
{
      // what can I do here? It appears I can **register** and work with Singleton/Scoped/Transient services 
     // that are from this module-- even after the application has started ?!
}

In the examples, I see how Modules can hold Views and ViewModels. That's cool, but I would like to have some business logic in the Modules as well. In particular, I got a Factory Service and I would like have a Module add an implementation to this Factory Service in it's RegisterTypes override. Can I do that? It seems that I can.

The next question is, since I "loaded" the Module, how come there's no way to "unload" the Module? The fact that I can't find a way to unload a module and that makes me think I am misunderstanding the intention of Modules.

[brianlagunas]

The answer to your question is yes, you can put custom logic in modules and register your factories with the container.

In the case of WPF, loading a module is the process of adding an assembly (DLL) into the app domain at runtime. You cannot remove a DLL from an app domain once loaded.

[angelotrivelli]

Super, thanks!

I see now there's complications to unloading an assembly, didn't know about that!