EntityAxis.KeyMappers 0.2.0

EntityAxis.KeyMappers

EntityAxis.KeyMappers provides key mapping implementations for EntityAxis, allowing seamless conversion between application and database key types.

✨ Features

• Generic key mappers for common scenarios:
  • IdentityKeyMapper<T> for when key types are the same
  • StringToGuidKeyMapper for string-to-Guid conversion
  • StringToIntKeyMapper for string-to-integer conversion
• Easy to extend with custom key mappers
• Stateless implementations for optimal performance

📦 Installation

dotnet add package EntityAxis.KeyMappers

🧱 Available Key Mappers

IdentityKeyMapper<T>

A default implementation for when the application and database key types are the same. This mapper performs no conversion and simply returns the input key.

// Register in DI container
services.AddSingleton<IKeyMapper<int, int>, IdentityKeyMapper<int>>();

StringToGuidKeyMapper

Converts between string keys in the application layer and GUID keys in the database.

// Register in DI container
services.AddSingleton<IKeyMapper<string, Guid>, StringToGuidKeyMapper>();

StringToIntKeyMapper

Converts between string keys in the application layer and integer keys in the database.

// Register in DI container
services.AddSingleton<IKeyMapper<string, int>, StringToIntKeyMapper>();

🧪 Creating Custom Key Mappers

You can create custom key mappers by implementing the IKeyMapper<TAppKey, TDbKey> interface:

public class CustomKeyMapper : IKeyMapper<string, long>
{
    public long ToDbKey(string appKey) => long.Parse(appKey);
    public string ToAppKey(long dbKey) => dbKey.ToString();
}

🧠 Best Practices

• Register key mappers as singletons since they are stateless
• Ensure your key mappers handle edge cases (null values, invalid formats, etc.)
• Consider adding validation in your key mappers to catch conversion issues early
• Use the IdentityKeyMapper when your application and database key types are the same

🔗 Related Packages

• EntityAxis.Abstractions: Defines the IKeyMapper interface and core contracts
• EntityAxis.EntityFramework: Uses key mappers for database operations
• EntityAxis.MediatR: Works with key mappers for command/query handling
• EntityAxis.Registration: Provides extension methods for easy key mapper registration

📜 License

This project is licensed under the MIT License.