Binding singleton to multiple services in Ninject

Question

I have a problem which seems very similar to the one described in http://markmail.org/message/6rlrzkgyx3pspmnf which is about the singleton actually creating more than a sin

Answer 1

We used Ruben's method in our project, but found that it wasn't intuitive why you were going back to the Kernel in your binding. I created an extension method and helper class (below) so you can do this:

kernel.Bind().ToExisting().Singleton();

That seemed to express the intent more clearly to me.

public static class DIExtensions
{
    public static ToExistingSingletonSyntax ToExisting(this IBindingToSyntax binding)
    {
        return new ToExistingSingletonSyntax(binding);
    }
}

// Had to create this intermediate class because we have two type parameters -- the interface and the implementation,
// but we want the compiler to infer the interface type and we supply the implementation type.  C# can't do that.
public class ToExistingSingletonSyntax
{
    internal ToExistingSingletonSyntax(IBindingToSyntax binding)
    {
        _binding = binding;
    }

    public IBindingNamedWithOrOnSyntax Singleton() where TImplementation : T
    {
        return _binding.ToMethod(ctx => ctx.Kernel.Get()).InSingletonScope();
    }


    private IBindingToSyntax _binding;
}