Poltergeist (computer programming)
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In computer programming, a poltergeist (or gypsy wagon) is a short-lived, typically stateless object used to perform initialization or to invoke methods in another, more permanent class. The original definition is by Michael Akroyd 1996 - Object World West Conference:
- "As a gypsy wagon or a poltergeist appears and disappears mysteriously, so does this short lived object. As a consequence the code is more difficult to maintain and there is unnecessary resource waste. The typical cause for this antipattern is poor object design."
A poltergeist can often be identified by its name; they are often called "manager_", "controller_", "start_process", etc.
Poltergeists should not be confused with long-lived, state-bearing objects of a pattern such as Model-view-controller, or tier-separating patterns such as Business-Delegate.
To remove a poltergeist, delete the class and insert its functionality in the invoked class, possibly by inheritance or as a Mixin.
Poltergeists are examples of an anti-pattern.