Building a Mediator library in .NET from scratch

Title: Building a Mediator Library in .NET from Scratch

Step 1: Introduction

• The tutorial focuses on creating a mediator library in C# from scratch without any dependencies.
• The goal is to understand the thought process and challenges behind building such a library.

Step 2: Watch Introductory Video

• If you are new to the concept of a mediator pattern, watch the introductory video provided in the link at the beginning of the tutorial.
• Understanding the basics of the mediator pattern will help you follow along with the implementation.

Step 3: Set Up the Project

• Create a sample console app to demonstrate the usage of the mediator library.
• Set up an empty .NET Core library project where you will implement the mediator code.

Step 4: Define Request and Response Types

• Implement the request-response approach where a request is passed to the mediator, a handler processes it, and a response is returned.
• Create an interface IRequestResponse to enforce this behavior on handlers.

Step 5: Implement Request and Handler

• Create a sample request class like PrintToConsoleRequest with a text property.
• Implement a generic handler interface IHandler<TRequest, TResponse> with a HandleAsync method.

Step 6: Implement Handler Logic

• Implement a handler for PrintToConsoleRequest that prints the text to the console.
• Use dependency injection to resolve services within the handler.

Step 7: Implement Mediator Class

• Create a Mediator class that resolves handlers using a service resolver function.
• Use a dictionary to map requests to their corresponding handlers.

Step 8: Register Handlers with Dependency Injection

• Add a dependency injection extension method to automatically register handlers.
• Scan assemblies to detect request and handler types and register them with the DI container.

Step 9: Test the Mediator

• Create instances of requests and handlers in your console app.
• Use the mediator to handle requests and observe the responses in the console.

Step 10: Refactor for Efficiency

• Refactor the implementation to avoid using reflection for better performance.
• Consider optimizing the mediator library further based on specific requirements.

Step 11: Conclusion

• Summarize the key points learned from building the mediator library.
• Encourage further exploration and customization of the library for different use cases.

By following these steps, you can successfully create a mediator library in .NET from scratch and understand the core concepts behind its implementation.