Mediator pattern

The mediator pattern is a software design pattern that provides a unified interface (computer science) to a set of interfaces in a subsystem.

Usually a program is made up of a (sometimes huge) number of class (computer science). So the logic and Computation is distributed among these classes. However, as more classes are developed in a program, especially during maintenance and/or Refactoring, the problem of Communication between these classes may become more complex.

This makes the program harder to read and software maintenance. Furthermore, it can become difficult to change the program, since any change may affect code in several other classes.

The Mediator pattern addresses this problem by promoting looser coupling between these classes by being the only class that has detailed knowledge of the methods of other classes. Classes send messages to the mediator when needed and the Mediator passes them on to any other classes that need to be informed.