Smart.Resolver .NET - resolver library for .NET

What is this?

Smart.Resolver .NET is simplified resolver library, degradation version of Ninject.

• ASP.NET Core / Generic Host support
• Xamarin support (Code generation mode and Reflection mode both supported)
• Transient, Singleton, Container(child) and custom scope supported
• Callback, Constant provider supported
• Property injection supported (optional)
• Custom initialize processor supported
• Construct with parameter supported
• Constraint supported (like named)
• Missing handler supported (For automatic registration, Xamarin integration, open generic type, ...)
• Customization-first implementation, but not too late (see benchmark)

Usage example

public interface IService
{
}

public class Service : IService
{
}

public class Controller
{
    private IService Service { get; }

    public Controller(IService service)
    {
        Service = service;
    }
}

// Usage 
var config = new ResolverConfig();
config.Bind<IService>().To<Service>().InSingletonScope();
config.Bind<Controller>().ToSelf();

var resolver = config.ToResolver();

var controller = resolver.Get<Controller>();

NuGet

Id	Note
Usa.Smart.Resolver	Core libyrary
Usa.Smart.Resolver.Extensions.DependencyInjection	Microsoft.Extensions.DependencyInjection integration
Usa.Smart.Resolver.Xamarin	Xamarin DependencyService integration

Bindings

Supported binding syntax.

• Bind
• To

// Type IService to Service Type instance
config.Bind<IService>().To<Service>();

• ToSelf

// Type Controller to Controller Type instance
config.Bind<Controller>().ToSelf();

• ToMethod

// Type IScheduler to factory method
config.Bind<IScheduler>().ToMethod(x => x.Get<ISchedulerFactory>().GetScheduler());

• ToConstant

// Type Messenger to instance
config.Bind<Messenger>().ToConstant(Messenger.Default);

• InTransientScope
• InSingletonScope
• InScope
• Named
• WithConstructorArgument
• WithPropertyValue
• WithMetadata

Scope

Supported scope.

Transient (default)

• New instance created each time
• Lifecycle is not managed by resolver

config.Bind<TransientObject>().ToSelf().InTransientScope();

or

config.Bind<TransientObject>().ToSelf();

Singleton

• Single instance created and same instance returned
• Lifecycle managed by resolver (IScopeStorage) and Dispose called when resolver disposed

config.Bind<SingletonObject>().ToSelf().InSingletonScope();

Container

• Single instance created and same instance returned per child container
• Lifecycle managed by child container and Dispose called when resolver disposed

config.Bind<ScopeObject>().ToSelf().InContainerScope();

Custom

• You can create a custom scope

config.Bind<CustomeScopeObject>().ToSelf().InScope(new CustomeScope());

Attribute

Prepared by standard.

NamedAttribute

Naming constraint for lookup binding.

public class Child
{
}

public class Parent
{
    pulbic Child Child { get; }

    public Parent([Named("foo")] Child child)
    {
        Child = child;
    }
}

// Usage
var config = new ResolverConfig();
config.Bind<Child>().ToSelf().InSingletonScope().Named("foo");
config.Bind<Child>().ToSelf().InSingletonScope().Named("bar");
config.Bind<Parent>().ToSelf();

var resolver = config.ToResolver();

var parent = resolver.Get<Parent>();
var foo = resolver.Get<Child>("foo");
var bar = resolver.Get<Child>("bar");

Debug.Assert(parent.Child == foo);
Debug.Assert(parent.Child != bar);

InjectAttribute

Mark of property injection target or select constructor.

public class HasPropertyObject
{
    [Inject]
    public Target Target { get; set; }
}

Parameter

Set constructor argument or property value.

public class Sceduler
{
    public Sceduler(ITimer timer, int timeout)
    {
    }
}

// Usage
config.Bind<ITimer>().To<Timer>().InSingletonScope();
config.Bind<Sceduler>().ToSelf().InSingletonScope().WithConstructorArgument("timeout", 30);

Configuration

StandardResolver is constructed from sub-components. Change the sub-components in ResolverConfig, can be customized StandardResolver.

// Add custom processor to pipeline
public sealed class CustomInitializeProcessor : IProcessor
{
    public void Initialize(object instance)
    {
...
    }
}

config.UseProcessor<CustomInitializeProcessor>();

// Add custome scope
public sealed class CustomScope : IScope
{
    private static readonly ThreadLocal<Dictionary<IBinding, object>> Cache =
        new ThreadLocal<Dictionary<IBinding, object>>(() => new Dictionary<IBinding, object>());

    public IScope Copy(IComponentContainer components)
    {
        return this;
    }

    public Func<IResolver, object> Create(IBinding binding, Func<object> factory)
    {
        return resolver =>
        {
            if (Cache.Value.TryGetValue(binding, out var value))
            {
                return value;
            }

            value = factory();
            Cache.Value[binding] = value;

            return value;
        };
    }
}

config.Components.Add<CustomScopeStorage>();
config.Bind<SimpleObject>().ToSelf().InScope(new CustomScope());

Integration

See the sample project for details.

ASP.NET Core

public static class Program
{
    public static void Main(string[] args)
    {
        CreateWebHostBuilder(args).Build().Run();
    }

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureServices(services => services.AddSmartResolver())
            .UseStartup<Startup>();
}

public class Startup
{
...
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
    }

    public void ConfigureContainer(ResolverConfig config)
    {
        // Add component
    }
...
}

Generic Host

public static class Program
{
    public static async Task Main(string[] args)
    {
        await new HostBuilder()
            .UseServiceProviderFactory(new SmartServiceProviderFactory())
            .ConfigureContainer<ResolverConfig>(ConfigureContainer)
            .RunAsync();
    }

    private static void ConfigureContainer(ResolverConfig config)
    {
        // Add component
    }
}

Xamarin

var config = new ResolverConfig()
    .UseDependencyService();

var resolver = config.ToResolver();

Other

Ohter topics.

IInitializable

If the class implements Initializable, Initialized called after construct.

protected class InitializableObject : IInitializable
{
    public bool Initialized { get; private set; }

    public void Initialize()
    {
        Initialized = true;
    }
}

// Usage
config.Bind<InitializableObject>().ToSelf().InSingletonScope();

var obj = resolver.Get<InitializableObject>();

Debug.Assert(obj.Initialized);

Constraint

If custom constraints want is as follows:

// Create IConstraint implement
public sealed class HasMetadataConstraint : IConstraint
{
    public string Key { get; }

    public HasMetadataConstraint(string key)
    {
        Key = key;
    }

    public bool Match(IBindingMetadata metadata)
    {
        return metadata.Has(Key);
    }
}

// Create ConstraintAttribute derived class
public sealed class HasMetadataAttribute : ConstraintAttribute
{
    public string Key { get; }

    public HasMetadataAttribute(string key)
    {
        Key = key;
    }

    public override IConstraint CreateConstraint()
    {
        return new HasMetadataConstraint(Key);
    }
}

// Usage
public class Parent
{
    pulbic Child Child { get; }

    public Parent([HasMetadata("hoge")] Child child)
    {
        Child = child;
    }
}

config.Bind<Child>().ToSelf().InSingletonScope();
config.Bind<Child>().ToSelf().InSingletonScope().WithMetadata("hoge", null);
config.Bind<Parent>().ToSelf();

Benchmark (for reference purpose only)

Benchmark result on .NET Core 2.2 with Code generation mode.

Method	Mean	Error	StdDev	Gen 0	Gen 1	Gen 2	Allocated
Singleton	8.830 ns	0.0127 ns	0.0119 ns	-	-	-	-
Transient	10.706 ns	0.0115 ns	0.0102 ns	0.0057	-	-	24 B
Combined	14.928 ns	0.0106 ns	0.0099 ns	0.0057	-	-	24 B
Complex	47.246 ns	0.1279 ns	0.1196 ns	0.0324	-	-	136 B
Generics	9.892 ns	0.0580 ns	0.0543 ns	0.0057	-	-	24 B
MultipleSingleton	6.989 ns	0.0108 ns	0.0101 ns	-	-	-	-
MultipleTransient	62.508 ns	0.0715 ns	0.0634 ns	0.0438	-	-	184 B
AspNet	303.839 ns	0.2027 ns	0.1896 ns	0.1179	-	-	496 B

Unsupported

• AOP( ﾟдﾟ)､ﾍﾟｯ
• Method Injection (I don't need but it is possible to cope)
• Circular reference detection (Your design bug)