Design pattern, observer pattern

1. Design Pattern D ESIGN P ATTERN

2. Design Pattern Outline What is ? Why Design Pattern? Pattern In Action Observer Pattern SingleTon Pattern Classification Feedback

3. 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 *

4. Design Pattern Learn DP There are around 50(!)s of DPs Already done for you. So, We Won’t ** REINVENT THE WHEEL **

5. Design Pattern DP There are around 50(!)s of DPs Already done for you. So, We Won’t ** REINVENT THE WHEEL **

6. Design Pattern Pattern In action Google Alert / RSS Feed What Happens?

7. Design Pattern Pattern In action Google Alert / RSS Feed What Happens? 1. New user can subscribe any time

13. Design Pattern Pattern In action Solution is The OBSERVER PATTERN