How I can load a service dependency based on the route parameter?
My requirement is different, but I'll try to use a simple example. A user can select the shipping provider (UPS, Fedex...) and the information is as part of the request model or route. Based on the route, I need to load the service class.
How it can be done in Autofac OWIN? Help on this will be appreciated
When you use the Autofac's OWIN integration, each request creates a new lifetime scope in which the current IOwinContext is registered, as you can see here.
You could then delegate the creation of your service to a factory that would take a dependency on IOwinContext.
public class MyServiceFactory
{
private readonly IOwinContext _context;
public MyServiceFactory(IOwinContext context)
{
_context = context;
}
public IService Create()
{
// inspect the context and determine which service you need
// you could return, dependending on, let's say, the URL
// - UpsService()
// - FedexService()
}
}
One thing you'll need to make sure is that you register your factory as InstancePerLifetimeScope since the IOwinContext will be different for each request.
Do you need to work at the OWIN layer, though? It will make things harder, and possibly a bit hacky, since OWIN is really just the HTTP layer, so there's no such thing as route data.
If you use ASP.NET Web API, you could base the factory on the current HttpRequestMessage if you use the RegisterHttpRequestMessage extension method.
You can then access route data through request.GetRequestContext().RouteData. Note that GetRequestContext is an extension method in the System.Net.Http namespace.
If you use ASP.NET MVC, you can register the AutofacWebTypesModule in the container, itself registering quite a few types in the container.
One of those is HttpRequestContext which has a RouteData property, so you can inject this one in the factory and apply your logic.
