async/await in service registration or service resolution. #2353
Description
From @Antaris on Wednesday, October 14, 2015 3:10:50 AM
Is it possible to support async/await and Task based service resolution? I'll walk you through an example:
public class WorkContext : IWorkContext
{
public WorkContext(ISecurityContext securityContext)
{
SecurityContext = securityContext;
}
public ISecurityContext SecurityContext { get; private set; }
}
public class WorkContextFactory : IWorkContextFactory
{
private readonly ISecurityContextFactory _securityContextFactory;
public WorkContextFactory(ISecurityContextFactory securityContextFactory)
{
_securityContextFactory = securityContextFactory;
}
public async Task<IWorkContext> CreateWorkContext(CancellationToken cancellationToken = default(CancellationToken))
{
// Get the security context for the current user
var securityContext = await _securityContextFactory.GetForCurrentUser(cancellationToken);
return new WorkContext(securityContext);
}
}
In my example above, I'm defining some implementations of abstractions provided by my framework. In a dependency, the ISecurityContextFactory I implement a Task-based async/await model because I don't know that the actual implementation might do some DB work to say load the current user information.
When I come to wire up my services, I want to utilise my WorkContextFactory to build my type (seperation of concerns), so I might do something like the following:
yield return ServiceDescriptor.Scoped<IWorkContextFactory, WorkContextFactory>();
yield return ServiceDescriptor.Scoped<IWorkContext>(sp => sp.GetService<IWorkContextFactory>().CreateWorkContext().Result);
Obviously at the moment, I'm having to block until I get the result of Task<IWorkContext>, but it would be great if I could do something like:
yield return ServiceDescriptor.Scoped<IWorkContext>(sp => sp.GetService<IWorkContextFactory>().CreateWorkContext());
And have the DI system understand the Task result and await.
Is this possible?
Copied from original issue: aspnet/DependencyInjection#303