Domain Driven Design Core Helpers

Domain Driven Design Core Helpers is a lightweight helper library for implementing Domain-Driven Design (DDD) in .NET applications.
It provides abstract base classes for common building blocks such as Value Objects and Entities, along with a simple Result type to standardize success/failure handling.

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✨ Features

• 🔹 Abstract Entity base class with identity handling.
• 🔹 Abstract ValueObject base class with equality and immutability support.
• 🔹 Result class for clean success/failure operations without exceptions.
• 🔹 Designed for .NET 9.0+ and modern C#.

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✨ Result Types

The package introduces different Results to represent the outcome of operations, allowing for clear handling of success, failure, and error propagation. Results are designed to be hierarchically convertible, meaning lower-level results can be implicitly converted into higher-level results while preserving their data.

There are two main categories of results:

• Non-typed results: These contain general information about the operation, including:

  • Success status
  • Failure types (if any)
  • Error messages
  • The layer in which the failure occurred (e.g., Service layer)

• Typed results: These inherit all functionality from non-typed results, in addition to:

  • the result's output type
  • The result's output (will throw error if the result is a failure)

Hierarchical Conversion

Results can be converted up the hierarchy. For instance, an EntityResult can be implicitly converted to a ServiceResult. This conversion retains all original values, and if the target result type is associated with a specific layer, the conversion will automatically assign the layer information.

Result Hierarchy

From lowest to highest in the hierarchy:

• 🔹 ValueObjectResult: Used for creating value objects.
• 🔹 EntityResult: Used within entity classes for domain-specific operations. The typed version only returns an Entity object.
• 🔹 MapperResult: Used for object mapping operations.
• 🔹 InfraResult: Used in the infrastructure layer for non-repository operations.
• 🔹 RepoResult: Used in the infrastructure layer for repository operations. Can only contain an AggregateRoot.
• 🔹 ServiceResult: Used in the service layer for domain-specific applications.
• 🔹 UseCaseResult: Used in the use case layer. Typically, results are converted to this type when propagating outward.
• 🔹 Result: A generic result type that can be used anywhere in the application.

📦 Installation

dotnet add package DDD.Core.Components