generic-async-composition-roots-with-constraints.md

Generic async composition roots with constraints

Important

`Resolve' methods cannot be used to resolve generic composition roots.

using Pure.DI;

DI.Setup(nameof(Composition))
    // This hint indicates to not generate methods such as Resolve
    .Hint(Hint.Resolve, "Off")
    .Bind().To<Dependency<TTDisposable>>()
    .Bind().To<Service<TTDisposable, TTS>>()
    // Creates OtherService manually,
    // just for the sake of example
    .Bind("Other").To(ctx =>
    {
        ctx.Inject(out IDependency<TTDisposable> dependency);
        return new OtherService<TTDisposable>(dependency);
    })

    // Specifies to use CancellationToken from the argument
    // when resolving a composition root
    .RootArg<CancellationToken>("cancellationToken")

    // Specifies to create a regular public method
    // to get a composition root of type Task<Service<T, TStruct>>
    // with the name "GetMyRootAsync"
    .Root<Task<IService<TTDisposable, TTS>>>("GetMyRootAsync")

    // Specifies to create a regular public method
    // to get a composition root of type Task<OtherService<T>>
    // with the name "GetOtherServiceAsync"
    // using the "Other" tag
    .Root<Task<IService<TTDisposable, bool>>>("GetOtherServiceAsync", "Other");

var composition = new Composition();

// Resolves composition roots asynchronously
var service = await composition.GetMyRootAsync<Stream, double>(CancellationToken.None);
var someOtherService = await composition.GetOtherServiceAsync<BinaryReader>(CancellationToken.None);

interface IDependency<T>
    where T : IDisposable;

class Dependency<T> : IDependency<T>
    where T : IDisposable;

interface IService<T, TStruct>
    where T : IDisposable
    where TStruct : struct;

class Service<T, TStruct>(IDependency<T> dependency) : IService<T, TStruct>
    where T : IDisposable
    where TStruct : struct;

class OtherService<T>(IDependency<T> dependency) : IService<T, bool>
    where T : IDisposable;

Running this code sample locally

• Make sure you have the .NET SDK 9.0 or later is installed

dotnet --list-sdk

• Create a net9.0 (or later) console application

dotnet new console -n Sample

• Add reference to NuGet package
  • Pure.DI

dotnet add package Pure.DI

• Copy the example code into the Program.cs file

You are ready to run the example 🚀

dotnet run

Important

The method Inject()cannot be used outside of the binding setup.

The following partial class will be generated:

partial class Composition
{
  private readonly Composition _root;

  [OrdinalAttribute(128)]
  public Composition()
  {
    _root = this;
  }

  internal Composition(Composition parentScope)
  {
    _root = (parentScope ?? throw new ArgumentNullException(nameof(parentScope)))._root;
  }

  [MethodImpl(MethodImplOptions.AggressiveInlining)]
  public Task<IService<T4, bool>> GetOtherServiceAsync<T4>(CancellationToken cancellationToken)
    where T4: IDisposable
  {
    TaskFactory<IService<T4, bool>> perBlockTaskFactory2;
    CancellationToken localCancellationToken74 = cancellationToken;
    TaskCreationOptions transientTaskCreationOptions3 = TaskCreationOptions.None;
    TaskCreationOptions localTaskCreationOptions75 = transientTaskCreationOptions3;
    TaskContinuationOptions transientTaskContinuationOptions4 = TaskContinuationOptions.None;
    TaskContinuationOptions localTaskContinuationOptions76 = transientTaskContinuationOptions4;
    TaskScheduler transientTaskScheduler5 = TaskScheduler.Default;
    TaskScheduler localTaskScheduler77 = transientTaskScheduler5;
    perBlockTaskFactory2 = new TaskFactory<IService<T4, bool>>(localCancellationToken74, localTaskCreationOptions75, localTaskContinuationOptions76, localTaskScheduler77);
    Func<IService<T4, bool>> perBlockFunc1 = new Func<IService<T4, bool>>(
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    () =>
    {
      OtherService<T4> transientOtherService6;
      IDependency<T4> localDependency79 = new Dependency<T4>();
      transientOtherService6 = new OtherService<T4>(localDependency79);
      IService<T4, bool> localValue78 = transientOtherService6;
      return localValue78;
    });
    Task<IService<T4, bool>> transientTask0;
    // Injects an instance factory
    Func<IService<T4, bool>> localFactory80 = perBlockFunc1;
    // Injects a task factory creating and scheduling task objects
    TaskFactory<IService<T4, bool>> localTaskFactory81 = perBlockTaskFactory2;
    // Creates and starts a task using the instance factory
    transientTask0 = localTaskFactory81.StartNew(localFactory80);
    return transientTask0;
  }

  [MethodImpl(MethodImplOptions.AggressiveInlining)]
  public Task<IService<T4, T1>> GetMyRootAsync<T4, T1>(CancellationToken cancellationToken)
    where T4: IDisposable
    where T1: struct
  {
    TaskFactory<IService<T4, T1>> perBlockTaskFactory2;
    CancellationToken localCancellationToken82 = cancellationToken;
    TaskCreationOptions transientTaskCreationOptions3 = TaskCreationOptions.None;
    TaskCreationOptions localTaskCreationOptions83 = transientTaskCreationOptions3;
    TaskContinuationOptions transientTaskContinuationOptions4 = TaskContinuationOptions.None;
    TaskContinuationOptions localTaskContinuationOptions84 = transientTaskContinuationOptions4;
    TaskScheduler transientTaskScheduler5 = TaskScheduler.Default;
    TaskScheduler localTaskScheduler85 = transientTaskScheduler5;
    perBlockTaskFactory2 = new TaskFactory<IService<T4, T1>>(localCancellationToken82, localTaskCreationOptions83, localTaskContinuationOptions84, localTaskScheduler85);
    Func<IService<T4, T1>> perBlockFunc1 = new Func<IService<T4, T1>>(
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    () =>
    {
      IService<T4, T1> localValue86 = new Service<T4, T1>(new Dependency<T4>());
      return localValue86;
    });
    Task<IService<T4, T1>> transientTask0;
    // Injects an instance factory
    Func<IService<T4, T1>> localFactory87 = perBlockFunc1;
    // Injects a task factory creating and scheduling task objects
    TaskFactory<IService<T4, T1>> localTaskFactory88 = perBlockTaskFactory2;
    // Creates and starts a task using the instance factory
    transientTask0 = localTaskFactory88.StartNew(localFactory87);
    return transientTask0;
  }
}

Class diagram:

---
 config:
  class:
   hideEmptyMembersBox: true
---
classDiagram
	OtherServiceᐸT4ᐳ --|> IServiceᐸT4ˏBooleanᐳ : "Other" 
	ServiceᐸT4ˏT1ᐳ --|> IServiceᐸT4ˏT1ᐳ
	DependencyᐸT4ᐳ --|> IDependencyᐸT4ᐳ
	Composition ..> TaskᐸIServiceᐸT4ˏBooleanᐳᐳ : TaskᐸIServiceᐸT4ˏBooleanᐳᐳ GetOtherServiceAsyncᐸT4ᐳ(System.Threading.CancellationToken cancellationToken)
	Composition ..> TaskᐸIServiceᐸT4ˏT1ᐳᐳ : TaskᐸIServiceᐸT4ˏT1ᐳᐳ GetMyRootAsyncᐸT4ˏT1ᐳ(System.Threading.CancellationToken cancellationToken)
	TaskᐸIServiceᐸT4ˏBooleanᐳᐳ o-- "PerBlock" FuncᐸIServiceᐸT4ˏBooleanᐳᐳ : "Other"  FuncᐸIServiceᐸT4ˏBooleanᐳᐳ
	TaskᐸIServiceᐸT4ˏBooleanᐳᐳ o-- "PerBlock" TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ : TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ
	TaskᐸIServiceᐸT4ˏT1ᐳᐳ o-- "PerBlock" FuncᐸIServiceᐸT4ˏT1ᐳᐳ : FuncᐸIServiceᐸT4ˏT1ᐳᐳ
	TaskᐸIServiceᐸT4ˏT1ᐳᐳ o-- "PerBlock" TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ : TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ
	FuncᐸIServiceᐸT4ˏBooleanᐳᐳ *--  OtherServiceᐸT4ᐳ : "Other"  IServiceᐸT4ˏBooleanᐳ
	TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ o-- CancellationToken : Argument "cancellationToken"
	TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ *--  TaskCreationOptions : TaskCreationOptions
	TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ *--  TaskContinuationOptions : TaskContinuationOptions
	TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ *--  TaskScheduler : TaskScheduler
	FuncᐸIServiceᐸT4ˏT1ᐳᐳ *--  ServiceᐸT4ˏT1ᐳ : IServiceᐸT4ˏT1ᐳ
	TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ o-- CancellationToken : Argument "cancellationToken"
	TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ *--  TaskCreationOptions : TaskCreationOptions
	TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ *--  TaskContinuationOptions : TaskContinuationOptions
	TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ *--  TaskScheduler : TaskScheduler
	OtherServiceᐸT4ᐳ *--  DependencyᐸT4ᐳ : IDependencyᐸT4ᐳ
	ServiceᐸT4ˏT1ᐳ *--  DependencyᐸT4ᐳ : IDependencyᐸT4ᐳ
	namespace Pure.DI.UsageTests.Generics.GenericAsyncCompositionRootsWithConstraintsScenario {
		class Composition {
		<<partial>>
		+TaskᐸIServiceᐸT4ˏT1ᐳᐳ GetMyRootAsyncᐸT4ˏT1ᐳ(System.Threading.CancellationToken cancellationToken)
		+TaskᐸIServiceᐸT4ˏBooleanᐳᐳ GetOtherServiceAsyncᐸT4ᐳ(System.Threading.CancellationToken cancellationToken)
		}
		class DependencyᐸT4ᐳ {
			+Dependency()
		}
		class IDependencyᐸT4ᐳ {
			<<interface>>
		}
		class IServiceᐸT4ˏBooleanᐳ {
			<<interface>>
		}
		class IServiceᐸT4ˏT1ᐳ {
			<<interface>>
		}
		class OtherServiceᐸT4ᐳ {
		}
		class ServiceᐸT4ˏT1ᐳ {
			+Service(IDependencyᐸT4ᐳ dependency)
		}
	}
	namespace System {
		class FuncᐸIServiceᐸT4ˏBooleanᐳᐳ {
				<<delegate>>
		}
		class FuncᐸIServiceᐸT4ˏT1ᐳᐳ {
				<<delegate>>
		}
	}
	namespace System.Threading {
		class CancellationToken {
				<<struct>>
		}
	}
	namespace System.Threading.Tasks {
		class TaskContinuationOptions {
				<<enum>>
		}
		class TaskCreationOptions {
				<<enum>>
		}
		class TaskFactoryᐸIServiceᐸT4ˏBooleanᐳᐳ {
		}
		class TaskFactoryᐸIServiceᐸT4ˏT1ᐳᐳ {
		}
		class TaskScheduler {
				<<abstract>>
		}
		class TaskᐸIServiceᐸT4ˏBooleanᐳᐳ {
		}
		class TaskᐸIServiceᐸT4ˏT1ᐳᐳ {
		}
	}

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