Dependency Injection

Nowadays is difficult to think in not use dependency injection in our applications, everything is much easier with DI.

We can easily inject the mapper instance passing the contract IMapper where we need it.

Here is an example using the Microsoft.Extensions.DependencyInjection but we can use it with any DI container.

public void ConfigureServices(IServiceCollection services)
{
    // ...

    // Mapping Engine
    var provider = new MappingProvider();

    MappingConfigurationSetup.ConfigCustomMappings(provider);

    services.AddSingleton<IMapper, Mapper>(s => new Mapper(provider));

    // ...
}

// this is just for instance

public class MappingConfigurationSetup
{
    public static void ConfigCustomMappings(IMappingProvider provider)
    {
        // ... custom configurations
    }
}

Now is just inject it where we need.

public abstract class ApplicationService
{
    private readonly IMapper _mapper;

    public ApplicationService(IMapper mapper)
    {
        _mapper = mapper;
    }

    public TOutput Map<TOutput>(object input)
    {
        return _mapper.Map<TOutput>(input);
    }
}


public class CustomerAppService : ApplicationService
{
    private readonly ICustomerService _customerService;

    public CustomerAppService(ICustomerService customerService, IMapper mapper) : base(mapper)
    {
        _customerService = service;
    }

    public List<CustomerDto> GetCustomers()
    {
        return Map<List<CustomerDto>>(_customerService.GetCustomers());
    }

    public CustomerDto FindById(int id)
    {
        return Map<CustomerDto>(_customerService.FindById(id));
    }

    // ...
}