Building a Custom Object Mapper in ASP.NET Core Using C#

Introduction

Data transformation and mapping between different object types are frequently required in application development. In ASP.NET Core applications, an object mapper simplifies this process by facilitating the conversion of data from one format to another. This article explores how to create a custom object mapper using C# in ASP.NET Core.

Object Mapping

Object mapping involves transferring data between objects of different types. Consider scenarios where you need to convert data from a database entity model to a DTO (Data Transfer Object) or from an external API response to an internal representation. This is where an object mapper plays a crucial role.

Implementing a Custom Object Mapper

Step 1. Define Mapping Configuration

Begin by creating a mapping configuration class where you define how objects should be mapped. For instance.

public class ObjectMapper
{
    public TDestination Map<TSource, TDestination>(TSource source)
    {
        // Implement logic to map source to destination
        // Example: return Mapper.Map<TSource, TDestination>(source);
    }
}

Step 2. Implement Mapping Logic

Inside the Map method, including the logic to map properties from the source object to the destination object. You might use reflection, libraries like AutoMapper, or manual mapping based on your project's requirements.

Step 3. Usage in ASP.NET Core Application

Once the custom object mapper is ready, use it in your ASP.NET Core controllers or services.

public class SampleController : ControllerBase
{
    private readonly ObjectMapper _objectMapper;

    public SampleController(ObjectMapper objectMapper)
    {
        _objectMapper = objectMapper;
    }

    public IActionResult MapObjects()
    {
        // Retrieve data from database or external API
        var sourceObject = GetDataFromSource();

        // Map to the desired destination object
        var destinationObject = _objectMapper.Map<SourceObject, DestinationObject>(sourceObject);

        // Perform actions with the mapped object
        // Return result or continue processing
    }
}

Benefits of a Custom Object Mapper

1. Customization: Tailor mapping logic to specific requirements.
2. Performance: Optimize mapping for better performance.
3. Maintainability: Centralize mapping logic for easy maintenance.
4. Testing: Simplify testing of mapping functionality.

Considerations

• Complexity: Custom mappers might require additional maintenance.
• Performance Overhead: Implementations could impact performance compared to established libraries like AutoMapper.
• Testing: Thoroughly test the mapping logic to ensure accurate data transfer.

Conclusion

Object mapping is a crucial aspect of data transformation in ASP.NET Core applications. Building a custom object mapper provides flexibility and control over data conversion processes. By following these steps and considering the associated factors, you can create a reliable custom object mapper tailored to your project's needs.

Start by understanding the mapping requirements, implementing the logic, and integrating the mapper within your ASP.NET Core application to streamline data processing effectively.

Happy coding!