Publish/Subscribe Pattern
The Observer Method is often associated with the Publish/Subscribe pattern. In this pattern, there is a message broker (or event bus) that acts as an intermediary between publishers (objects producing events) and subscribers (objects interested in specific events). Publishers send events to the broker, and subscribers subscribe to specific event types.
In this diagram:
- Publisher: This is the source of data or events. It publishes data to specific topics.
- Subscriber: These are entities interested in receiving data or events from specific topics.
- Topic: It’s like a channel or category that acts as an intermediary between publishers and subscribers. It stores the list of subscribers for a specific type of data or event.
How it Works:
- Publishing: The Publisher publishes data to a particular Topic. It’s like a radio station broadcasting on a specific channel.
- Subscribing: Subscribers express their interest by subscribing to specific Topics. They say, “I want to listen to data from this channel.”
- Forwarding: When the Publisher sends data to a Topic, the Topic forwards that data to all Subscribers interested in that Topic. It’s like broadcasting a message to everyone tuned to a particular radio channel.
Observer Method – JavaScript Design Pattern
Observer design pattern, a staple of behavioral design patterns in JavaScript, provides a means to establish a one-to-many relationship between objects. This design pattern is especially valuable for decoupling components and facilitating extensibility in software applications. By employing this pattern, you can have one object (the subject) notify multiple observers (subscribers) about changes or events without requiring them to have direct knowledge of each other. This decoupling enhances maintainability and extensibility in your software projects.
Important Topics for Observer Method in JavaScript
- Participants of Observer Pattern in JavaScript:
- Implementation of Observer Method:
- Diagram Explanation of Observer Method in JavaScript
- Publish/Subscribe Pattern:
- Differences Between Observer and Publish/Subscribe Patterns:
- Advantages of the Observer Method:
- Disadvantages of the Observer Method:
- Conclusion :
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