Extending ResourceManagerStringLocalizer functionality - asp.net-core

Question

I am fairly new to .net core and I want to implement localization in my application. The built in ResourceManagerStringLocalizer service satisfies almost all my requirements and works great out of the box, but I want to add some custom functionality to it, without copy pasting all of the class' code and adding some to it in my own localizer. Currently I have tried deriving from the class in my own Localizer and injecting that as my IStringLocalizer:
services.AddTransient<IStringLocalizer<MyApp.SharedResource>, MyLocalizer<MyApp.SharedResource>>();
...
public class MyLocalizer<T> : ResourceManagerStringLocalizer, IStringLocalizer<T> {
public MyLocalizer(ResourceManager resourceManager, IResourceStringProvider resourceStringProvider, string baseName, IResourceNamesCache resourceNamesCache, ILogger logger) : base(resourceManager, resourceStringProvider, baseName, resourceNamesCache, logger) {
}
public override LocalizedString this[string name] {
get {
//do some custom functionality
return base[name];
}
}
public override LocalizedString this[string name, params object[] arguments] {
get {
//do some custom functionality
return base[name, arguments];
}
}
}
But this gives the following exception when trying to use it:
System.InvalidOperationException: 'Unable to resolve service for type 'System.Resources.ResourceManager' while attempting to activate 'MyApp.Services.MyLocalizer`1[MyApp.SharedResource]'.'
My question is, what's the best way to this? And whats best practice for doing things like this? I feel like this sort of stuff may come up more often in the future of this application and all help will be appreciated.

Answer 1

You don't have to override the built-in localizer, just implement your custom one:
public class MyLocalizer
{
private readonly IStringLocalizer _localizer;
public MyLocalizer(IStringLocalizerFactory factory)
{
var type = typeof(MyResourceType);
var assemblyName = new AssemblyName(type.GetTypeInfo().Assembly.FullName);
_localizer = factory.Create("MyResourceType", assemblyName.Name);
}
public LocalizedString this[string name]
{
get
{
// ...
return _localizer[name];
}
}
public LocalizedString this[string name, params object[] arguments]
{
get
{
// ...
return _localizer[name, arguments];
}
}
}
Then you can simple inject it to the views:
#inject MyLocalizer _loc;
<h1>#_loc["Hellow"]</h1>
or to the backend:
public class HomeController : Controller
{
private readonly MyLocalizer _loc;
public HomeController(MyLocalizer loc)
{
_loc = loc;
}
public IActionResult Index()
{
var msg = _loc["Welcome"];
//...
}
}