Design pattern, unveil the mystery and find the fantastic... Contact me at: koh2203@gmail.com https://facebook.com/kiennx

1. DESIGN PATTERNS
And where to find them

2. ABOUT ME
 Nguyễn Xuân Kiên
 Techlead at Shippo.vn
 Experienced with
 ASP.NET
 JAVA
 PHP
 Javascript

3. DESIGN PATTERNS
 A reusable solution to a common problem
 A template or description for how to solve a problem
 A practice that has been tried
 A Fantastic beast, not mystical

4. A BOOK BY “GANG OF FOUR”
Only proven design patterns
Applicable for Object-Oriented Software

5. THE PROBLEM
 A simple CRUD problem
 We have many transactions or queries
 Same code at many places

6. THE SIMPLE WAY

7. REFACTORED

8. CONTINUE TO REFACTOR

9. SINGLETON
 Ensure there is only one instance in the whole application
 Has a global access point, allow easy access
 May hide the constructor

10. THE PROBLEM
 There are many Brand Name SMS Service Providers
 We need at least 2 usable service (1 for backup)
 Each service has different interface
 The switching should be as quick as possible

11. THE SIMPLE WAY

12. REFACTORED

13. SAME INTERFACE, DIFFERENT API

14. ADAPTER
 Provide new interface for existing classes
 Make different classes use same interface without modification
 Switchable API

15. SAME AS BEFORE, WITH ADAPTERS

16. REFACTORED

17. FACTORY METHOD
 Create objects without exposing its constructor
 Create objects of the same interfaces, with subclasses define which
class to create instance
 Flexible object creating

18. COMBINE ALL THREE

19. 4 TYPES OF PATTERN
 Creational
 Structure
 Behavioral
 Concurrency

20. CONCLUSION
 It’s a template, or a description, not a module or library
 It can be extended, modified to suit your project and your problem
 Many patterns can be sew together
 It’s a matter of architecture

21. TIME FOR Q & A

22. THANKS FOR YOUR
ATTENTION