Dryioc and Microsoft Dependency injection with servicekey

[jfield-igniteous]

I have a Dryioc container into which I register a number of components. One of these registrations uses a servicekey lookup to resolve a dependency at runtime.

builder.Register<IErpData, ErpData>(Reuse.Singleton, serviceKey: "local");
var erpAccessParams = Parameters.Of
.Name("erpData", (request) =>
{
// Perform late lookup to determine which concrete instance to inject
var erpAccess = builder.Resolve(serviceKey:"local");
return erpAccess;
});

builder.Register(made: Made.Of(parameters: erpAccessParams));

A MS IHostBuilder instance is used to set up the initial container definition for MS registrations via a call to IHostBuilder.UseServiceProviderFactory(new DryIocServiceProviderFactory());

The odd behaviour I'm seeing is that the Parameters.Of.Name lambda is never called to revolve the constructor argument in some situations.

If I use the following:

builder.RegisterDelegate((context) =>
{
return context.Resolve();
});
builder.Register();

Then the resolution works. It seems to be an issue on matching parameters. How does this constructor parameter selection process work in combination with MS DI container?

[dadhi]

@jfield-igniteous

I would avoid this kind of context based resolutions:

builder.Register<IErpData, ErpData>(Reuse.Singleton, serviceKey: "local");
var erpAccessParams = Parameters.Of
.Name("erpData", (request) =>
{
// Perform late lookup to determine which concrete instance to inject
var erpAccess = builder.Resolve(serviceKey:"local");
return erpAccess;
});

builder.Register(made: Made.Of(parameters: erpAccessParams));

Here, you are actually resolving the parameter value of a specific key as a resolution root and then using it for injection.

Instead, it is much simpler to configure the injection of parameter erpData directly.

builder.Register<Foo>(made: Parameters.Of.Name("erpData", serviceKey: "local"));

If you need the Runtime based condition (do you really?), then add 2 registrations and selective condition:

builder.Register<Foo>(made: Parameters.Of.Name("erpData", serviceKey: "local"), setup: Setup.With(condition: _ => env.IsDev));
builder.Register<Foo>(made: Parameters.Of.Name("erpData", serviceKey: "prod"), setup: Setup.With(condition: _ => env.IsProd));

[jfield-igniteous]

Thank you for that feedback. I will adjust how I make these types of registrations . The resolution is based on configuration data that is read in at runtime to determine which of the data providers to use. E.g Sql or Access for example.

However the issue I am seeing is that the parameter selectors are not be executed at all when creating the components via a MS dependency injection container (via an external framework). I have a suspicion that the way the framework code is passing in an empty array of parameters for the constructor arguments is steering ctor resolution to a default ctor (without the parameter)

Is there a way to steer this resolution by ignoring the parameters being passed in from the framework? Or to arrange the priority of containers definitions over those passed in? If so, I'll try and see if this steers the ctor matcher correctly.

[dadhi]

The support for keyed services for MS.DI is not yet released. But it only matters if the client calls your code expecting a keyed service. If you register via DryIoc container and not via the ServiceCollection - it should work.

So to undertstand your particular issue I need more context.

[jfield-igniteous]

There might be an interception point within Akka.NET to reroute the request to create an actor away from the MS DI ActivatorUtulities, and direct to the ServiceProvider instance (Dryioc) in this case. I will try this today.

I would prefer to avoid tightly coupling my code with MS DI just to make it work with Dryioc.

[jfield-igniteous]

As an aside, I really appreciate the fantastic work you've done (and continue to do) with the DryIoc product. You're always very responsive and helpful. Thank you.

[dadhi]

Anyway, I have pushed DryIoc v6.0.0-preview-06 and DryIoc.Microsoft.DependencyInjection v8.0.0-preview-01 to NuGet.

[jfield-igniteous]

I'm working on a basic POC for Akka.NET that wraps DryIoc directly to perform resolutions, without using ServiceProvider wrapper. It seems to work so far with the original configuration (parameter section and servicekeys). I'll keep you posted if I find any issues.

[dadhi]

Great, if you will publish a repo please send me a link.