Dependency Inversion Principle.md

Abstract

High level modules should not depend on concrete implementations

To avoid this, we can instead move that dependency to an Interface, which means our module is now loosely coupled to a contract that can be fulfilled by any class as required instead of needing to adjust to a rigid implementation of the expected shape of its dependencies.

tags: [[Object Oriented Programming]] [[Design Principles]]

Example

public class MyController : Controller
{
	public MyController(IRepository repository)
	{
		// the declaration of IRepository as the type allows us to 
		// decouple from any set implementation of the repository
	}
}

public class MyRepository : IRepository
{
	// this implementation must abide by the contract set  in IRepository
}

public class TestRepository : IRepository
{
	 // this implementation must abide by the same     contract
	 // but it can be used 
}