Override services

Any manually registered service can be overridden. This is useful for multiple reasons, like mocking or replacing a third-party service with your own implementation.

The syntax between registering a service and overriding a service is the same, the only difference is that you use the override method instead of register.

Overriding a service

If you want to specify a new implementation for a service, you can use the override method. This method accepts the registered service type and optionally the new implementation type.

using TheRealIronDuck.Ducktion.Configurators;

public interface ILogger {}
public class DebugLogger : ILogger {}
public class FileLogger : ILogger {}

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        // Let's assume that the DebugLogger is registered somewhere else
        container.Override<ILogger, FileLogger>();
    }
}

using TheRealIronDuck.Ducktion.Configurators;

public interface ILogger {}
public class DebugLogger : ILogger {}
public class FileLogger : ILogger {}

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        // Let's assume that the DebugLogger is registered somewhere else
        container.Override<ILogger, FileLogger>();
    }
}

This will replace the DebugLogger with the FileLogger implementation.

WARNING

When you override any service, it will delete the singleton instance of the service if it exists.

Overriding service configuration

You can also override any service configuration value, like the Lazy Mode or the Singleton Mode. This is useful when you want to change the behavior of a service without replacing the implementation.

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override<ILogger>().NonSingleton().Lazy();
    }
}

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override<ILogger>().NonSingleton().Lazy();
    }
}

Alternative syntax

You can also use the Override method with type arguments instead of generic types. This is useful when you want to override a service with a dynamic type.

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override(typeof(MyService)).Singleton();
        container.Override(typeof(ILogger), typeof(FileLogger));
    }
}

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override(typeof(MyService)).Singleton();
        container.Override(typeof(ILogger), typeof(FileLogger));
    }
}

TIP

We recommend using the generic syntax, as it provides better auto completion and type safety. However, both syntaxes are supported and function the same.

Ids

If services are registered with an id, you can override them by using the same id.

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override<ILogger>(id: "file-logger").Singleton();
        container.Override<ILogger, DebugLogger>(id: "debug-logger");
    }
}

using TheRealIronDuck.Ducktion.Configurators;

public class MyConfigurator : MonoDiConfigurator
{
    public void Register(DIContainer container)
    {
        container.Override<ILogger>(id: "file-logger").Singleton();
        container.Override<ILogger, DebugLogger>(id: "debug-logger");
    }
}

For more information about ids, see the ID Documentation.