“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice”
Christopher Alexander
Defines a family of algorithms encapsulates each one, and make them interchangeable. Strategy lets the algorithm vary independetly from clients that use it.
Defines a one-to-many dependency between objects so that when one object changes state, all it’s dependents are notified and updated automatically.
Attaches additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extending functionality.
Define an interface for creating an object, but lets subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.
Provides an interface for creating families of related or dependent objects without specifying their concrete classes.
Ensures a class has only one instance, and provides a global point of access to it.
Encapsulates a request as an object, thereby letting you parameterize other objects with different requests, queue or log requests, and support undoable operations.
Converts the interface of a class into another interface the clients expects. Adapter lets classes work together that couldn’t otherwise because of incompatible interfaces.
Provides an unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use.
Defines the skeleton of an algorithm in a method, deferring some steps to subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the algorithm’s structure.
Provides a way to access the elements of an aggregate object sequentially without exposing its underlying representation.
Allows you to compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly.
Allows an object to alter its behavior when its internal state changes. The object will appear to change its class.
Provides a surrogate or placeholder for another object to controll access to it.
Separate the construction of a complex object from its representation allowing the same construction process to create various representations.
Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype.
Translates a grammar to a recursive-descent recognizer that matchers phrases and sentences in the language specified by grammar.
A Compound Pattern combines two or more patterns into a solution that solves a recurring or general pattern.
The MVC is a compound pattern consisting of the Observer, Strategy and Composite patterns.
A Messaging Pattern is a network-oriented architectural pattern which describes how two different parts of a message passing system connect and communicate with each other.