Facade Design Pattern in C#

This project demonstrates the implementation of the Facade Design Pattern in C#. The Facade Pattern provides a unified interface to a set of interfaces in a subsystem. It simplifies the interaction with complex systems by creating a higher-level interface that makes the system easier to use.

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Project Structure

The project is structured as follows:

1. Entities

• Contains the core entities of the application: Product, Customer, and Order.
• These classes represent the data models used in the application.

2. Services

• ProductService: Handles operations related to Product.
• CustomerService: Handles operations related to Customer.
• OrderService: Handles operations related to Order.
• These services interact with the fake database to fetch and manipulate data.

3. Facade Service

• OrderFacade: Acts as a unified interface that simplifies order placement and retrieval.
• Internally uses ProductService, CustomerService, and OrderService.

4. Endpoints

• EndPointsWithFacade: Implements order-related operations (Place Order, Get Orders) using the facade.
• EndPointsWithOutFacade: Implements the same operations without the facade, demonstrating the complexity it simplifies.

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Features

1. Place Order

• Allows customers to place an order for a product.
• Validates whether the customer and product exist before creating the order.

2. Get Orders

• Fetches the list of orders with detailed information about the customer and product.

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Why Use the Facade Pattern?

Without Facade:

• Direct calls to multiple services increase code complexity.
• Developers need to understand the implementation details of each service.

With Facade:

• A single OrderFacade simplifies the interaction between services.
• Encapsulates the complexity of coordinating ProductService, CustomerService, and OrderService.

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How to Run the Project

Prerequisites:

• .NET 6.0 or higher.
• Visual Studio or any C# IDE.

Steps:

1. Clone the repository:

   git clone <repository-url>
   

2. Navigate to the project directory.
3. Run the application:

   dotnet run

4. Use Swagger UI to test the endpoints:
   • Access Swagger at: https://localhost:<port>/swagger.

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API Endpoints

1. With Facade

• POST /api/facade/
  Place an order.
  Query Parameters:

  • customerId (int)
  • productId (int)
  • quantity (int)

• GET /api/facade/
  Get the list of orders.

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2. Without Facade

• POST /api/withoutfacade/
  Place an order without using the facade.
  Query Parameters:

  • customerId (int)
  • productId (int)
  • quantity (int)

• GET /api/withoutfacade/
  Get the list of orders without using the facade.

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Example Requests

Place Order (With Facade)

POST /api/facade?customerId=1&productId=1&quantity=2

Response:

"Order placed successfully!"

Get Orders (With Facade)

GET /api/facade

Response:

[
  {
    "id": 1,
    "productId": 1,
    "customerId": 1,
    "quantity": 2,
    "customer": {
      "id": 1,
      "name": "John Doe"
    },
    "product": {
      "id": 1,
      "name": "Laptop",
      "price": 1000.0
    }
  }
]

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Technologies Used

• C#
• ASP.NET Core Minimal API
• Swagger for API documentation

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Resources

Video Tutorials:

• YouTube: بررسی Facade Design Pattern و موارد استفاده از آن

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Credits

Develop By AliCharper

Refactor by Mohammad.
Feel free to reach out for feedback or collaboration!