In the future I’d like to explore and write about similar architectures applied to other programming paradigms such as Functional Programming. This layer contains the implementation of the behaviour contracts defined in the Model layer. Business Logic behaviour is declared as contracts with the use of interfaces in a Object-Oriented context. It is the level of dependency of one thing upon another. The higher the coupling, the lower the ability to change and evolve the system. By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Implementation of Onion Architecture

Now, we create an index view, as per the code snippet, mentioned below under the User folder of views. Now, we create a UserProfile entity, which inherits from the BaseEntity class. The code snippet, mentioned below is for the UserProfile entity. Now, we create an User entity, which is inherited from BaseEntity class. The code snippet, mentioned below is for the User entity.

👨‍💻 Authentication And Authorization In .NET Core Web API Using JWT Token And Swagger UI

The Onion architecture was first introduced by Jeffrey Palermo, to overcome the issues of the traditional N-layered architecture approach. Now our service layer contains the reference of the repository layer. But here we need to add the project reference of the Domain layer in the repository layer. Write click on the project and then click the Add button after that we will add the project references in the Repository layer. Add the Data in the domain that is used to add the database context class. The database context class is used to maintain the session with the underlying database using which you can perform the CRUD operation.

Implementation of Onion Architecture

The GET request for the DeleteUser action method returns _DeleteUser partial View. The code snippet mentioned below is under the User folder of Views. The GET request for the EditUser action method returns _EditUser partial view, where code snippet onion software architecture follows under the User folder of views. The GET request for the AddUser action method returns _AddUser partial view; the code snippet follows under the User folder of views. Now, we create action method, which returns an index view with the data.

Software Design and Architecture (30 Part Series)

Thanks for this great article,I am agree that you are saying you are going to build boilerplate that any one can download and can start working. CQS also tends to imply immediate consistency between the read and write models, while CQRS often implies eventual consistency between the read and write models. You should use different projects when you need different deliverables.

  • Maybe an Entity Framework Core Layer for Accessing the DB, a Layer specifically made to generate JWT Tokens for Authentication or even a Hangfire Layer.
  • IAPIDateFormatter implementation must know how API wants to receive the date objects.
  • You have made it clear and simple though yet not confident with it because I know the coding part will be application-specific and hence will differ here and there.
  • With layered and hexagonal architectures understood, the time has come to talk about a relative – Onion Architecture, which puts a new spin on layers.
  • If an application is developed with the ORM entity framework then this layer holds POCO classes or Edmx with entities.
  • These interfaces can be implemented with an adapter that connects to another microservice by exposing HTTP Rest, GRPC, Thrift Endpoints, etc.

We create one more interface named IUserProfileService. This interface holds method signature which is accessed by the external layer for the UserProfile entity. The following code snippet is for the same (IUserProfileService.cs). This interface holds all methods signature which accesses by external layer for the User entity. The following code snippet is for the same (IUserService.cs).


I have already written a detailed article on MediatR and CQRS patterns in ASP.NET Core 3.1 WebApi Project. You can follow that article and add the Required Commands and Handlers to the Application Layer. To keep things simple but demonstrate the architecture to the fullest, we will build an ASP.NET Core Web API that is quite scalable. For this article, Let’s have a WebApi that has just one entity, Product.

It depends on how organized you want your project to be and how comfortable you are with the patterns. For instance, your Commands may use a service bus or Event Sourcing to send changes on for further processing, while your Queries may use compiled SQL views for querying. Using different projects for different layers is only ever coincidentally a good idea. You’d have to have a very large project before doing that made any sense, in which case moving the application into a more service-based architecture might well be a better choice. This will be an Empty API Controller which will have API Versioning enabled in the Attribute and also a MediatR object. We will not have to re-define the API Versioning route or the Mediator object.

What is Onion architecture?

This layer is intended to build loosely coupled applications. This layer communicates to both Web applications and repository projects. These interfaces communicate between UI and data access logic. As it communicates via interfaces, it builds applications that are loosely coupled.

Implementation of Onion Architecture

But you will surely end up having both EF and ADO.NET working side by side. Onion / Hexagonal architecture is ideal for Monolith Applications. I have a full fledged Solution template that can get you started real easy.

Unfolding infrastructure in the Onion architecture

All dependencies are specified in the gradle configuration and build files. Please refer to this actual source of truth regarding the current dependencies, since this README might be out of date. This class will hold the common properties used in product and product details entity, right now we have only ProductId, but it will grow as the application grows.

What doesn't exist today might become tomorrow's ultimate solution. Clean architecture incorporates principles like SOLID and domain-driven design and enforces them through module structuring during compilation. However, it's important to note that not everything can be enforced at compile time. The project comes with gradle build files, including the project module structure and dependencies as well as the external dependencies. See gradle.settings in the root directory and in the modules.

Preface: where to place my code?

Coupling between components and between layers is a much better quality heuristic, and onion architecture is all about managing that coupling. Let’s look at one of the most popular Architecture in ASP.NET Core Applications. Here is a simple diagrammatic representation of a variation of the N-Layer Architecture. The presentation Layer usually holds the Part that the User can interact with, i.e, WebApi, MVC, Webforms, and so on.


Vaša email adresa neće biti objavljena javno.