Post on 17-Nov-2014
description
Design Pattern DESIGNP
AT
TE
RN
Design Pattern
OutlineWhat is ?
Why Design Pattern?Pattern In ActionObserver PatternSingleTon PatternClassificationFeedback
Design Pattern
What is DP
General *Reusable* solution to Commonly Occurring problem(Experience Reuse Rather Code Reuse)
Description or Template for how to
Solve A *Common Problem*
Design Pattern
Learn DP
There are around 50(!)s of DPs Already done for you.
So, We Won’t **REINVENT THE WHEEL**
Design Pattern
DP
There are around 50(!)s of DPs Already done for you.
So, We Won’t **REINVENT THE WHEEL**
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1. New user can subscribe any time
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1.New user can subscribe any time2.Existing user can De subscribe
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1.New user can subscribe any time2.Existing user can Desubscribe
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1.New user can subscribe any time2.Existing user can Desubscribe
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1.New user can subscribe any time2.Existing user can Desubscribe3.When any updates (Google) automatically Flood this to all subcribers
Design Pattern
Pattern In action
Google Alert / RSS Feed
What Happens?1.New user can subscribe any time2.Existing user can Desubscribe3.When any updates (Google) automatically Flood this to all subcribers
Design Pattern
Pattern In action
Solution is The OBSERVER PATTERN