Design Pattern

A Patter is a soluction to a problem in a context.

• The context, is the situation in witch the pattern applies. This should be a recurring situation.

• The problem, refers to the goal you are trying to achieve in this context, but it also refers to any constraints that occur in the context.

• The soluction, is what you're after: a general design tha anyone can apply which resolves the goal and set of constraints.

Patterns into categories:

Creational: Involve object instantiation and all provide a way to decouple a client from the objects it needs to instantiate.

• Singleton
• Builder
• Prototype
• Abstract Fatory
• Factory Method

Structural: Let you compose classes or objects into larger structures.

• Decorator
• Composite
• Flyweight
• Adapter
• Bridge
• Facade
• Proxy

Behavioral: Is concerned with how classes and objects interact and distribute responsibility.

• Template Method
• Command
• Iterator
• Observer
• Strategy
• State
• Chain of Responsibility
• Mememnto
• Mediator
• Visitor