MVP Pattern Demo Application

A comprehensive demonstration of the Model-View-Presenter (MVP) pattern using ASP.NET Web Forms and SQLite, implementing SOLID principles and clean architecture practices.

🏗️ Architecture Overview

This application demonstrates proper implementation of the MVP pattern with clear separation of concerns:

📁 Project Structure

MyModelViewPresenter/
├── Core/                           # Domain layer - Business entities and contracts
│   ├── Models/                     # Domain entities
│   │   └── Product.cs              # Product entity with validation
│   ├── Repositories/               # Repository contracts
│   │   └── IProductRepository.cs   # Data access contract
│   └── Services/                   # Business service contracts
│       └── IProductService.cs      # Business logic contract
├── Infrastructure/                 # Infrastructure layer - Data access and services
│   ├── Repositories/               # Repository implementations
│   │   └── ProductRepository.cs    # SQLite data access implementation
│   ├── Services/                   # Service implementations
│   │   └── ProductService.cs       # Business logic implementation
│   └── DependencyInjection/        # DI container
│       └── ServiceContainer.cs     # Simple IoC container
├── Presentation/                   # Presentation layer - MVP components
│   ├── Views/                      # View contracts
│   │   └── IProductView.cs         # View interface
│   ├── Presenters/                 # Presenter implementations
│   │   └── ProductPresenter.cs     # MVP presenter
│   └── Infrastructure/             # Presentation infrastructure
│       └── PresenterFactory.cs     # Presenter factory
├── Web/                           # Web layer - ASP.NET Web Forms
│   ├── Default.aspx               # Home page
│   ├── ProductManagement.aspx     # Product management page
│   └── Site.Master               # Master page with modern UI
└── Tests/                         # Unit tests
    └── ProductServiceTests.cs     # Service layer tests

🎯 Design Patterns Implemented

1. Model-View-Presenter (MVP)

• Model: Domain entities (Product) and business logic (IProductService)
• View: ASP.NET Web Forms pages implementing view interfaces (IProductView)
• Presenter: Orchestrates between View and Model (ProductPresenter)

2. Repository Pattern

• Abstracts data access through IProductRepository
• Enables easy testing and database switching
• Implements async operations for better performance

3. Service Layer Pattern

• Business logic encapsulated in IProductService
• Validation and business rules centralized
• Returns structured results with error handling

4. Factory Pattern

• PresenterFactory creates presenters with proper dependencies
• Manages presenter lifecycle
• Supports dependency injection

5. Dependency Injection

• Simple IoC container (ServiceContainer)
• Constructor injection throughout the application
• Enables testability and loose coupling

🔧 SOLID Principles Applied

S - Single Responsibility Principle

• Each class has one reason to change
• ProductService handles only business logic
• ProductRepository handles only data access
• ProductPresenter handles only presentation logic

O - Open/Closed Principle

• Interfaces allow extension without modification
• New repositories can be added implementing IProductRepository
• New services can implement IProductService

L - Liskov Substitution Principle

• All implementations can replace their interfaces
• ProductRepository can be substituted with any IProductRepository
• Mock objects used in tests demonstrate this principle

I - Interface Segregation Principle

• Interfaces are focused and cohesive
• IProductView contains only view-related operations
• IProductRepository contains only data operations

D - Dependency Inversion Principle

• High-level modules don't depend on low-level modules
• Presenters depend on service abstractions
• Services depend on repository abstractions
• Dependencies are injected through constructors

🚀 Features

Functional Features

• ✅ Create, Read, Update, Delete (CRUD) products
• ✅ Search products by name and description
• ✅ Form validation with custom business rules
• ✅ Responsive modern UI with dark/light theme
• ✅ Real-time feedback with loading states
• ✅ SQLite database with sample data

Technical Features

• ✅ Async/await throughout the application
• ✅ Proper error handling and logging
• ✅ Input validation and sanitization
• ✅ Unit testing with mocking
• ✅ Dependency injection
• ✅ Clean architecture with separation of concerns

🛠️ Technology Stack

• Framework: .NET Framework 4.8
• Web: ASP.NET Web Forms
• Database: SQLite with Dapper ORM
• UI: Bootstrap 5 with custom styling
• Testing: MSTest with Moq
• Icons: Bootstrap Icons

📋 Prerequisites

• Visual Studio 2019 or later
• .NET Framework 4.8
• IIS Express (included with Visual Studio)

🚀 Getting Started

1. Clone the repository

   git clone <repository-url>
   cd MyModelViewPresenter

2. Open in Visual Studio

   • Open MyModelViewPresenter.sln

3. Build the solution

   • Build → Build Solution (Ctrl+Shift+B)

4. Run the application

   • Set Web as startup project
   • Press F5 to run

5. Database Setup

   • Database is created automatically on first run
   • Sample data is inserted automatically
   • Database location: Web/App_Data/products.db

🧪 Running Tests

1. Open Test Explorer

   • Test → Test Explorer

2. Run All Tests

   • Click "Run All" in Test Explorer
   • Tests demonstrate proper mocking and isolation

📊 Key Benefits

For Developers

• Testability: Easy unit testing with mocked dependencies
• Maintainability: Clear separation of concerns
• Extensibility: New features can be added easily
• Readability: Well-organized code with clear responsibilities

For Business

• Reliability: Comprehensive validation and error handling
• Performance: Async operations and optimized database access
• User Experience: Modern, responsive interface
• Scalability: Clean architecture supports growth

📚 Learning Objectives

This application demonstrates:

1. MVP Pattern Implementation

   • Proper separation of View, Model, and Presenter
   • Event-driven communication between layers

2. SOLID Principles in Practice

   • How to apply each principle in real code
   • Benefits of following these principles

3. Clean Architecture

   • Dependency flow from outer to inner layers
   • Interface-based design for testability

4. Modern Web Development

   • Responsive design principles
   • Progressive enhancement
   • Accessibility considerations

5. Best Practices

   • Error handling strategies
   • Validation patterns
   • Testing approaches

🔍 Code Quality Features

• Comprehensive Documentation: XML comments on all public members
• Error Handling: Structured error handling with user-friendly messages
• Validation: Both client-side and server-side validation
• Logging: Debug logging for troubleshooting
• Resource Management: Proper disposal of resources
• Performance: Async operations and efficient database queries

🎨 UI/UX Features

• Modern Design: Clean, professional interface
• Responsive Layout: Works on desktop and mobile devices
• Dark/Light Theme: User preference support
• Loading States: Visual feedback during operations
• Form Validation: Real-time validation feedback
• Accessibility: Proper ARIA labels and keyboard navigation

🚀 Future Enhancements

Potential improvements for learning purposes:

• Authentication & Authorization: User management system
• Caching: In-memory or Redis caching
• Logging Framework: NLog or Serilog integration
• API Layer: REST API for external access
• Advanced Validation: FluentValidation library
• Database Migrations: Structured database versioning
• Performance Monitoring: Application insights
• Containerization: Docker support

📖 Additional Resources

• MVP Pattern Explained
• SOLID Principles
• Clean Architecture
• Repository Pattern

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This application serves as a comprehensive reference for implementing clean architecture principles in .NET applications, demonstrating both theoretical concepts and practical implementation details.

LLM Notice: This project contains code generated by Large Language Models such as Claude and Gemini. All code is experimental whether explicitly stated or not.