Observer Pattern
Observer pattern is used when there is one-to-many relationship between objects such as if one object is modified, its depenedent objects are to be notified automatically. Observer pattern falls under behavioral pattern category. Observer pattern uses three actor classes. Subject, Observer and Client. Subject is an object having methods to attach and detach observers to a client object. We have created an abstract class Observer and a concrete class Subject that is extending class Observer.
Example:
Implementing real-time notifications in a chat application using the Observer pattern.
The Observer defines a one-to-many relationship so that when one object changes state, the others are notified and updated automatically. Some auctions demonstrate this pattern. Each bidder possesses a numbered paddle that is used to indicate a bid. The auctioneer starts the bidding, and “observes” when a paddle is raised to accept the bid. The acceptance of the bid changes the bid price which is broadcast to all of the bidders in the form of a new bid.
Latest Design Patterns for Web Development
Design patterns are typical solutions to common problems in software design. Rather than being a code solution, they are general concepts you can implement in your software to expect certain behavior from it. Design patterns are not specific to any programming language or technology, but they can be implemented in different ways depending on the specific technology being used.
Design patterns are used in web development to create applications that are maintainable, efficient, and scalable. They provide a way to structure code and data in a way that is both easy to understand and maintain.
Important Topics for the Latest Design Patterns for Web Development
- Types of Design Patterns
- 1. Model View Controller(MVC)
- 2. Model View Presenter(MVP)
- 3. Model View ViewModel(MVVM)
- 4. Singleton Pattern
- 5. Factory Method Pattern
- 6. Decorator Pattern
- 7. Observer Pattern
- 8. Adapter Pattern
- 9. Dependency Injection Pattern
- 10. Repository Pattern
- 11. Strategy Pattern
- 12. Command Pattern
- 13. Middleware Pattern
- 13. Caching Patterns
- 14. Front Controller Pattern