E13.Common.Domain 2025.117.22

E13.Common.Domain

Overview

E13.Common.Domain is a package within the E13.Common collection that provides core domain abstractions and patterns for building domain-driven applications. It defines interfaces and base classes for domain entities and implements the specification pattern for encapsulating business rules.

Features

• Entity Interfaces: Core interfaces for domain entities (IEntity, ICreatable, IModifiable, IDeletable)
• Specification Pattern: Implementation of the specification pattern for business rules
• Composable Specifications: Support for combining specifications using logical operators (And, Or, Not)
• Entity Lifecycle: Interfaces for tracking entity lifecycle (creation, modification, deletion)
• Expiration Support: Interface for entities with expiration dates

Installation

dotnet add package E13.Common.Domain

Usage

Creating Domain Entities

using E13.Common.Domain;

// Basic entity
public class Product : IEntity
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
}

// Entity with tracking information
public class Customer : IEntity, ICreatable, IModifiable, IDeletable
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    
    // ICreatable implementation
    public string? CreatedBy { get; set; }
    public string? CreatedSource { get; set; }
    public DateTime? Created { get; set; }
    
    // IModifiable implementation
    public string? ModifiedBy { get; set; }
    public string? ModifiedSource { get; set; }
    public DateTime? Modified { get; set; }
    
    // IDeletable implementation
    public string? DeletedBy { get; set; }
    public string? DeletedSource { get; set; }
    public DateTime? Deleted { get; set; }
    
    // IDeletable provides this method automatically
    // public bool IsDeleted() => Deleted != null;
}

Using the Specification Pattern

using E13.Common.Domain.Specifications;

// Create a specification for active customers
public class ActiveCustomerSpecification : Specification<Customer>
{
    public override Expression<Func<Customer?, bool>> ToExpression()
    {
        return customer => customer != null && customer.Deleted == null;
    }
}

// Create a specification for premium customers
public class PremiumCustomerSpecification : Specification<Customer>
{
    public override Expression<Func<Customer?, bool>> ToExpression()
    {
        return customer => customer != null && customer.IsPremium;
    }
}

// Using specifications
var activeSpec = new ActiveCustomerSpecification();
var premiumSpec = new PremiumCustomerSpecification();

// Combine specifications
var activePremiumSpec = activeSpec.BitwiseAnd(premiumSpec);

// Check if a customer satisfies the specification
bool isPremiumActive = activePremiumSpec.IsSatisfiedBy(customer);

// Use with LINQ
var activePremiumCustomers = dbContext.Customers
    .Where(activePremiumSpec.ToExpression())
    .ToList();

Dependencies

• .NET 9.0

Related Packages

E13.Common.Domain is part of the E13.Common collection, which includes:

• E13.Common.Core - Core utilities and base classes
• E13.Common.Data.Db - Database access components
• E13.Common.Api - Web API layer components
• E13.Common.AspNet - ASP.NET shared components
• E13.Common.Logic - Business logic components

Contributing

Contributions to E13.Common.Domain are welcome. If you have suggestions or improvements, please submit an issue or create a pull request in the GitHub repository.

License

This project is licensed under the MIT License. For more details, see the LICENSE file in the repository.