Inversion of Control- Part-03 (Service Locator)

•  Service Locator use K‡iI Avgiv Inversion of Control (IoC) implement Ki‡Z cvwi|

Ø  Dc‡iv³ diagram Abyhvqx OrderService Class OrderDatabase Class m¤ú‡K© AÁvZ _v‡K wKš‘ ServiceLocator Class m¤ú‡K© Rv‡b | Avevi ServiceLocator Class OrderDatabase m¤ú‡K© ÁvZ _v‡K|

Ø  hLb AcceptOrder invoke Kiv nq ZLb Bnv IOrderSaver Gi instance Gi Rb¨ ServiceLocator ‡K ask Ki‡e|

Ø  ServiceLocator ZLb IOrderSaver Gi D³ instance Gi Rb¨ configured class Gi instance supply Ki‡e|

Ø  ServiceLocator use K‡i OrderService Gi implementation wb¤œiƒc n‡e-

public class OrderService

{

    public void AcceptOrder(Order order)

    {

        //Domain logic such as validation

        OrderSaverFactory.GetOrderSaver().SaveOrder(order);

    }

}

Ø  ServiceLocator Gi implementation wb¤œiƒc n‡e-

public class ServiceLocator

{

    public static IOrderSaver OrderSaver { get; set; }

    public static IOrderSaver GetOrderSaver()

    {

        if (OrderSaver == null)

            OrderSaver = new OrderDatabase();

        return OrderSaver;

    }

}

Ø  GLv‡b cÖ_‡g IOrderSaver Gi GKwU static instance OrderSaver define Kiv n‡q‡Q

Ø  Then GetOrderSaver method Gi g‡a¨ check K‡i OrderSaver null wK bv|

Ø  hw` null nq Z‡e OrderDatabase class Gi GKwU new instance OrderSaver G initialize Kiv nq|