Inversion of Control

What is Inversion of Control?

Inversion of Control is a principle in software engineering by which the control of objects or portions of a program is transferred to a container or framework. It’s most often used in the context of object-oriented programming.

By contrast with traditional programming, in which our custom code makes calls to a library, IoC enables a framework to take control of the flow of a program and make calls to our custom code. To enable this, frameworks use abstractions with additional behavior built in. If we want to add our own behavior, we need to extend the classes of the framework or plugin our own classes.

The advantages of this architecture are:

  • decoupling the execution of a task from its implementation
  • making it easier to switch between different implementations
  • greater modularity of a program
  • greater ease in testing a program by isolating a component or mocking its dependencies and allowing components to communicate through contracts

Inversion of Control(IoC) can be achieved through various mechanisms such as: Strategy design pattern, Service Locator pattern, Factory pattern, and Dependency Injection.