This document discusses dependency injection in PHP. It describes how dependency injection can help reduce hard-coded dependencies, improve code reuse and testability by loosely coupling classes. The document outlines different types of dependency injection like constructor injection, setter injection and interface injection. It recommends using a dependency injection container for PHP like Twittee or Pimple to further simplify managing dependencies, though notes containers are not required for dependency injection. The document aims to convince developers that dependencies are useful if implemented properly using techniques like dependency injection.

1. Dependency Injection with PHP
Nikita Groshin
Nguyễn Huy Tuấn

2. Itim

More than 200 employees

More than 80 developers from different
countries

Different programming languages and
paradigm

Java, C++, PHP, JS, Python etc

3. Frontend and Tools Deprtment

13 members

PHP, JS, Python

Kohana, Zend Framework

100% Zend Certificated developers

4. Core Products

Search engine http://coccoc.vn/

Browser http://corom.vn

Not only

5. "Developers! Developers!
Developers"
"Dependency! Dependency!
Dependency"

6. Dependencies are suck?

NO. They are useful!

Hard code is suck

7. Good Dependency

8. Bad Dependency

9. Bad

10. Better

11. Good

12. Dependency Injection are simple.

13. Bad

14. Good

15. Injection types

Constructor injection

Setter injection

Interface injection

16. Interface Injection

17. Interface injection

18. Quite easy.
But why to use it?

19. Hard coded dependency

Hard to reuse

Poor isolation

Hard to test

A lot of code

Hard to maintain

Hard to understand

20. Dependency injection

Loose coupling

Reuse of code

Reduce amount of code

Clear and Understandable

Extremely easy to test

21. Dependency injection

Loose coupling

Reuse of code

Reduce amount of code

Clear and Understandable

Extremely easy to test

22. Extremely easy to test

23. Manual Di management is
complicated.

24. We need container!

25. Disclaimer

Dependency Injection != DI container

DI container use Service Locator Anti-Pattern

DI container make code 'less native'

Powerful tool – use careful

Often Manual injection is enough

26. How many lines of code
we need for simple
DI container?

27. Twittee

http://twittee.org/

Packed in less than 140 characters, it fits in a
tweet.

Author Fabien Potencier

Production ready

28. Twittee source

29. Pimple

http://pimple.sensiolabs.org/

50 lines of code

Full functionality

Author Fabien Potencier

Production ready

30. Questions?

job.coccoc.vn

nike-17@coccoc.vn