Inversion of Control approaches

 

0. Dependency Injection (DI)

• Description: DI is a design pattern that decouples object creation from usage by injecting dependencies at runtime, enhancing modularity and testability.
• Use Cases: Ideal for complex software systems requiring easy maintenance, testing, and flexibility, such as web applications.
• Drawbacks: Can introduce setup complexity, require a learning curve, and potentially lead to runtime errors if configurations are incorrect.

1. Service Locator Pattern

• Description: Unlike DI, where dependencies are pushed into an object, the Service Locator pattern involves an object requesting its dependencies from a central registry or locator.
• Use Cases: It can be useful in situations where DI might be overly complex or when there's a need for more dynamic resolution of dependencies.
• Drawbacks: It tends to hide the class dependencies, making them less explicit, which can lead to harder-to-read code and potentially more difficult debugging and testing.

2. (Abstract) Factory Pattern

• Description: The Factory Pattern is a creational pattern used to create objects without specifying the exact class of object that will be created. This is achieved by defining an interface for creating an object, but letting subclasses decide which class to instantiate.
• Use Cases: Useful when the creation process is complex or when it should be decoupled from the system's business logic.
• Drawbacks: It doesn't automatically manage dependencies like DI, potentially leading to more boilerplate code if dependencies are complex.

3. Singleton Pattern

• Description: Ensures a class has only one instance and provides a global point of access to it. This can be used to manage shared resources or configurations.
• Use Cases: Suitable for logging, driver objects, caching, thread pools, and configuration settings.
• Drawbacks: Overuse can lead to issues similar to global variables, making code tightly coupled, harder to test, and parallelize.

4. Constructor Injection without a Container

• Description: This approach manually injects dependencies through constructors without using a DI container.
• Use Cases: It's a simpler alternative for applications with fewer dependencies or where introducing a DI container would be considered overkill.
• Drawbacks: Can become cumbersome as the application grows, leading to complex constructor signatures and manual management of dependency graphs.

5. Static Methods/Classes

• Description: Using static methods or classes to provide services or functionalities without instantiating objects.
• Use Cases: Suitable for utility functions or when state management is not a concern.
• Drawbacks: Static methods can lead to tightly coupled code, making testing and mocking more difficult.

6. Registry Pattern

• Description: A registry pattern provides a system-wide registry of services or objects that can be accessed from anywhere in the application.
• Use Cases: Can be used for global access points to services or configurations, similar to service locators but with a simpler implementation.
• Drawbacks: Global access can lead to issues with maintainability and testability, as it introduces global state into an application.