bind-type-attribute.md

Bind type attribute

Shows how the Type attribute can declare a contract directly on an implementation type.

using Shouldly;
using Pure.DI;

DI.Setup(nameof(Composition))

    // Composition root
    .Root<IMessageWriter>("Writer");

var composition = new Composition();
var writer = composition.Writer;

writer.ShouldBeOfType<ConsoleMessageWriter>();

interface IMessageWriter;

[Type(typeof(IMessageWriter))]
class ConsoleMessageWriter : IMessageWriter;

Running this code sample locally

• Make sure you have the .NET SDK 10.0 or later installed

dotnet --list-sdk

• Create a net10.0 (or later) console application

dotnet new console -n Sample

• Add references to the NuGet packages
  • Pure.DI
  • Shouldly

dotnet add package Pure.DI
dotnet add package Shouldly

• Copy the example code into the Program.cs file

You are ready to run the example 🚀

dotnet run

Note

When a registered type attribute is applied to a class or struct, Pure.DI treats it as binding metadata for that implementation.

The following partial class will be generated

partial class Composition
{
  public IMessageWriter Writer
  {
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    get
    {
      return new ConsoleMessageWriter();
    }
  }
}

Class diagram:

---
 config:
  class:
   hideEmptyMembersBox: true
---
classDiagram
	ConsoleMessageWriter --|> IMessageWriter
	Composition ..> ConsoleMessageWriter : IMessageWriter Writer
	namespace Pure.DI.UsageTests.Attributes.BindTypeAttributeScenario {
		class Composition {
		<<partial>>
		+IMessageWriter Writer
		}
		class ConsoleMessageWriter {
				<<class>>
			+ConsoleMessageWriter()
		}
		class IMessageWriter {
			<<interface>>
		}
	}

Loading

See also:

• Bind attribute
• Bind type attributes