Dependency injection dos and donts

designnotes.txt

Dependency injection is effective in these situations:
  You need to inject configuration data into one or more components.
  You need to inject the same dependency into multiple components.
  You need to inject different implementations of the same dependency.
  You need to inject the same implementation in different configurations.
  You need some of the services provided by the container.
Dependency injection is not effective if:
  You will never need a different implementation.
  You will never need a different configuration.
If you know you will never change the implementation or configuration of some dependency, there is no benefit in using dependency injection.