observersubject

ObserverSubject is a design pattern that facilitates communication between objects. It establishes a one-to-many dependency between objects. When one object, known as the subject, changes its state, all objects that depend on it, called observers, are notified and updated automatically. This pattern promotes loose coupling, meaning the subject does not need to know the concrete classes of its observers. It only needs to know that they implement a specific observer interface.

The subject maintains a list of its observers. When a change occurs, it iterates through this list and calls an update method on each observer. Observers can register themselves with the subject to receive notifications and unregister when they no longer wish to be informed. This allows for dynamic addition and removal of observers.

Common use cases for the Observer pattern include graphical user interfaces, where UI elements (observers) need to react to changes in data models (subjects), and event handling systems, where multiple components might need to be notified of a specific event. The pattern is fundamental in building responsive and modular applications by decoupling the source of information from those that consume it.