System.Composition.Convention 9.0.18

About

System.Composition.Convention is part of the Managed Extensibility Framework (MEF) 2.0, a composition library for .NET that enables dependency injection through attributes or conventions.

This package simplifies the process of applying consistent patterns for part exports, imports, and metadata by using convention-based configurations. It is useful for scenarios where you want to avoid repetitive attribute-based decoration and instead define conventions for registering types in your composition container.

Key Features

• Configure exports, imports, and metadata for parts using conventions rather than attributes.
• Allows defining conventions through a fluent API, making configuration more flexible and readable.

How to Use

Configure parts for composition without using attributes.

using System.Composition.Convention;
using System.Composition.Hosting;

var conventions = new ConventionBuilder();

// Apply conventions: any class that implements ILogger will be exported as ILogger
conventions
    .ForTypesDerivedFrom<ILogger>()
    .Export<ILogger>();

var configuration = new ContainerConfiguration()
    .WithPart<FileLogger>(conventions)
    .WithPart<ConsoleLogger>(conventions);

using CompositionHost container = configuration.CreateContainer();
    
var loggers = container.GetExports<ILogger>();

foreach (var logger in loggers)
{
    logger.Log("Hello, World!");
}
// FileLogger: Hello, World!
// ConsoleLogger: Hello, World!

public interface ILogger
{
    void Log(string message);
}

public class FileLogger : ILogger
{
    public void Log(string message) => Console.WriteLine($"FileLogger: {message}");
}

public class ConsoleLogger : ILogger
{
    public void Log(string message) => Console.WriteLine($"ConsoleLogger: {message}");
}

Main Types

The main types provided by this library are:

• System.Composition.Convention.ConventionBuilder
• System.Composition.Convention.PartConventionBuilder
• System.Composition.Convention.ParameterImportConventionBuilder

Additional Documentation

• API documentation
• Managed Extensibility Framework (MEF)

Related Packages

• System.Composition
• System.Composition.AttributedModel
• System.Composition.Hosting
• System.Composition.Runtime
• System.Composition.TypedParts

Feedback & Contributing

System.Composition.Convention is released as open source under the MIT license. Bug reports and contributions are welcome at the GitHub repository.