Design Patterns

Transcript

1. Design Patterns Ruby Conf. Nigeria
2. ❖ Software Developer ❖ Consultant at Auth0 ❖ Open Sourcerer ❖ Self-Acclaimed Developer Evangelist ❖ Community Builder ❖ Jollof Rice Ambassador ❖ Google Developer Expert ❖ Homeless Man
3. @unicodeveloper - GitHub - Twitter
4. ...When no design pattern is involved.
6. ...After you involve design patterns.
8. ..A few things to note, thou developer
9. 1. Design patterns are not a silver bullet to all your problems.
10. 2. Design patterns was made for man, not man for design patterns.
11. 3. They can prove to be a savior, or else they can make you & your code a mess.
12. Design Patterns Grouped 1 2 ❖ Behavioral ❖ Creational ❖ Structural
13. Behavioral Design Patterns 1 3 ❖ Mediator ❖ Observer ❖ Strategy ❖ Visitor ❖ Iterator ❖ Command
14. Creational Design Patterns 1 4 ❖ Builder ❖ Prototype ❖ Singleton ❖ Factory ❖ Abstract Factory
15. Structural Design Patterns 1 5 ❖ Facade ❖ Composite ❖ Decorator ❖ Flyweight ❖ Adapter ❖ Bridge
16. ..Know JavaScript? I’ll use it as an example to explain the common design patterns that you should know & take advantage of in your codebase.
17. Singleton Pattern
18. Goals 1. Ensure that only one instance of a class is created. 2. Provide a global point of access to the object.
19. Singleton 1 9
20. Singleton 2 0 What makes the Singleton is the global access to the instance.
21. Prototype Pattern
22. Goals 1. Specify the kind of objects to create using prototypical instance. 2. Create new objects by copying this prototype
23. Prototype 2 3
24. Prototype 2 4
25. Command Pattern
26. Goals 1. Encapsulate the request in an object 2. Allow the parameterization of clients with different requests.
27. Command 2 7
28. Command 2 8 What if the core API of carManager changed? What happens?
29. Facade Pattern
30. Goals 1. Outward appearance to the world which hides a different reality. 2. Simpler public interface to avoid calling many internal methods to get some behavior working. 3. Ability to directly interact with subsystems in a way that can be less prone to accessing it directly.
31. Facade 3 1
32. Facade 3 2 JQuery’s document.ready() function is being powered by bindReady()
33. Factory Pattern
34. Goals 1. Creates objects without exposing the instantiation logic to the client. 2. Refer to newly created object through a common interface.
35. Factory 3 5
36. Factory 3 6
37. The Mixin Pattern
38. Goals 1. Allow objects to borrow functionality with a minimal amount of complexity.
39. Mixin 3 9
40. Mixin 4 0
41. Decorator Pattern
42. Goals 1. Similar to Mixins. Aim to promote code reuse 2. Offer ability to add behaviour to existing classes in a system dynamically.
43. Decorator 4 3 Simple Use case
44. Decorator 4 4
45. Decorator 4 5 Decorating objects with multiple decorators
46. Module Pattern
47. Goals 1. Emulate the concept of classes. 2. Shield particular parts from global scope and make everything simple.
48. Module 4 8
49. Module 4 9
50. Observer Pattern
51. Goals 1. Define a one to many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.
52. Observer 5 2
53. Observer 5 3
54. Observer 5 4
55. Observer 5 5
56. Observer 5 6
57. Observer 5 7
58. Learning Resource http://www.oodesign.com/observer-pattern.html https://addyosmani.com/resources/essentialjsdes ignpatterns/book/
59. Thank You!