Ninject Binding Constraint that searches up to find a type
I've got a class hierarchy like this (simplified):
class Connection
{
}
interface IService<T>
{
}
class ServiceImplementation : IService<int>
{
public ServiceImplementation(Connection)
{
}
}
interface IConnectionConfiguration
{
public void Configure(Connection c)
}
class ConnectionConfiguration : IConnectionConfiguration
{
public void Configure(Connection c)
}
Where I have multiple implementations of IConnectionConfiguration and IService. I am wanting to create a provider/bindings which:
- constructs a new instance of Connection.
- GetAll and applies that to the Connection.
- Bindings specify which IConnectionConfiguration implementations to be used, based on on the type of IService to be开发者_如何学JAVA constructed
Currently I have a provider implementation like this:
public Connection CreateInstance(IContext context)
{
var configurations = context.Kernel.GetAll<IConnectionConfiguration>()
var connection = new Connection();
foreach(var config in configurations)
{
config.Configure(connection);
}
return connection;
}
But when I try to make the contextual binding for IConnectionConfiguration it doesn't have a parent request or parent context...
Bind<IConnectionConfiguration>().To<ConcreteConfiguration>().When(ctx => {
// loop through parent contexts and see if the Service == typeof(IService<int>);
// EXCEPT: The ParentRequest and ParentContext properties are null.
});
What am I doing wrong here? Can I do this with ninject?
By calling kernel.GetAll
you are creating a new request. It has no information about the service context. There is an extension that allows you to create new requests that preserve the original context (Ninject.Extensions.ContextPreservation)
See also https://github.com/ninject/ninject.extensions.contextpreservation/wiki
context.GetContextPreservingResolutionRoot().GetAll<IConnectionConfiguration>();
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