A Gang of Four behavioral design pattern that defines a one-to-many dependency between objects so that when one object, the subject, changes state, every object registered as its observer is notified and updated automatically.
Facts
Core PrincipleDefines a one-to-many dependency between a subject and its observers so that when the subject changes state, all its registered observers are notified automatically. 2 Connections
Associated With
Erich Gamma, Pioneers Erich Gamma co-authored the 1994 Design Patterns book that named and catalogued the Observer pattern among the original 23.
In Field
Sources
1. Wikipedia: Design Patterns (book)
Wikimedia FoundationLead section, first sentenceQuote, Lead section, first sentence
Design Patterns: Elements of Reusable Object-Oriented Software (1994) is a software engineering book describing software design patterns.
2. Wikipedia: Observer Pattern
Wikimedia FoundationLead section, first sentence
the observer pattern is a software design pattern in which an object, called the subject (also known as event source or event stream), maintains a list of its dependents, called observers (also known as event sinks), and automatically notifies them of any state changes
In Group: Software Design Patterns, Lead
In software design and software engineering, the observer pattern is a software design pattern in which an object, called the subject (also known as event source or event stream), maintains a list of its dependents, called observers (also known as event sinks), and automatically notifies them of any state changes, typically by calling one of their methods.
View the Source Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.
Sign in to dispute this or suggest a correction.