Your SlideShare is downloading. ×
0
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Observer pattern
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Observer pattern

647

Published on

Observer pattern explained

Observer pattern explained

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
647
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
20
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Observer PatternShahriar Iqbal Chowdhury & Monjurul Habib Code Name: Remington http://www.facebook.com/groups/netter/
  • 2. Observer Defined• Hes a silent guardian. A watchful protector. A Dark Knight.
  • 3. Pattern States Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically
  • 4. Applicability• When an abstraction has two aspects, one dependent on the other. Encapsulating these aspects in separate objects lets you vary and reuse them independently.• When a change to one object requires changing others, and you dont know how many objects need to be changed.• When an object should be able to notify other objects without making assumptions about who these objects are. In other words, you dont want these objects tightly coupled.
  • 5. Observer @ Gotham City
  • 6. Example (Notify on Withdrawal)
  • 7. Subject
  • 8. Concrete Subject
  • 9. Observer
  • 10. ConcreteObserverConcreteObserver
  • 11. Invoke
  • 12. Advantages1. Eliminates dependencies2. Increases extensibility3. Improves testability
  • 13. Observer & .NET framework• Model View Controller Pattern - The observer pattern is used in the model view controller (MVC) architectural pattern. In MVC the this pattern is used to decouple the model from the view. View represents the Observer and the model is the Observable object.• The introduction of delegates and events provides a new and powerful means of implementing the Observer pattern

×