Clean Architecture Using ASP.NET

What is Clean Architecture? Clean Architecture, synonymous with concepts such as Onion, Hexagonal, and Ports-and-Adapters, structures code to minimize dependencies on infrastructure. This fosters testability and maintainability, aligning well with Domain-Driven Design and microservices.

Traditional vs. Clean Architecture: Before Clean Architecture's rise, architectures often centered around the database, leading to rigid dependencies and testing challenges. The Clean Architecture paradigm shifts the focus, reducing infrastructure reliance and encouraging a domain-centric approach.

When to Use Clean Architecture:

• Emphasizing domain models over infrastructure in domain-driven design.
• Managing complex business logic that necessitates superior testability.

Clean Architecture deters infrastructural concerns from seeping into the domain, streamlining both development and testing processes.

Pros and Cons: Traditional N-tiered architectures offer simplicity and clear separation by infrastructure. However, they may lack scalability and create complexity, impacting testability due to intertwined dependencies. Clean Architecture counters these issues with domain separation, deployability, and inbuilt best practices.

Demonstration via Tools: Utilizing tools like the Ardalis.CleanArchitecture.Template template can exemplify Clean Architecture's principles in practice in ASP.net Core. You can also use following command for initializing the same

dotnet new install Ardalis.CleanArchitecture.Template::9.0.1        

Clean Architecture Rules:

• Business rules and entities are central in the core project.
• Dependencies gravitate toward the core project.
• Inner projects define interfaces; outer projects implement these using dependency injection.

Project Structure:

• Core: Defines interfaces, entities, value objects, and aggregates, orchestrating complex relationships within the domain.
• Domain Services: Hosts logic not situated within Aggregates, Entities, or Value Objects.
• Domain Exceptions: Custom exceptions replace generic .NET exceptions for domain-specific error handling.
• Domain Events and Event Handlers: Facilitate domain-internal events and related actions, enhanced by .NET 8's observability features.

Command Query Responsibility Segregation (CQRS): This optional pattern separates read and write responsibilities, potentially enhancing clarity and performance in complex systems.

Infrastructure: The infrastructure layer implements interfaces from the Core, often encompassing persistence mechanisms, repositories, and various service clients.

Web Project: An ASP.NET project includes API endpoints, Razor Pages, Controllers, and other components necessary for a responsive web application.

Shared Kernel: A Shared Kernel project contains common elements used across Domain-Driven Design (DDD) projects, providing a unified foundation for various domain models.

Best Practices and Case Studies:

• Adhering to SOLID principles and clear separation of concerns is paramount in Clean Architecture.
• Real-world case studies demonstrate Clean Architecture's successful application and the value it brings.

Comparison with Other Architectural Patterns:

• A thoughtful comparison with other patterns can guide architects in choosing the right approach for their specific context.

Challenges and Strategies:

• Common challenges in adopting Clean Architecture include overcoming the learning curve and integrating with existing legacy systems. Strategies to address these challenges include incremental refactoring and comprehensive team training.

Migration Path:

• For projects transitioning to Clean Architecture, a step-by-step migration guide can facilitate the process, ensuring minimal disruption.

More Information:

• GitHub - ardalis/CleanArchitecture: Clean Architecture Solution Template: A starting point for Clean Architecture with ASP.NET Core
• GitHub - dotnet-architecture/eShopOnWeb: Sample ASP.NET Core 7.0 reference application, powered by Microsoft, demonstrating a layered application architecture with monolithic deployment model. Download the eBook PDF from docs folder.
• ASP.NET Core application architecture guidance (microsoft.com)

• Hack Together - https://aka.ms/hacktogether/dotnet
• Learn collection - https://aka.ms/learn-dotnet-8
• Local Events - https://aka.ms/dotnetconf-local-event
• Hero blog - https://aka.ms/dotnet8blog