Primož Gabrijelčič - Hands-On Design Patterns with Delphi

Gaurav Aroraa has an M.Phil in computer science. He is a Microsoft MVP; a lifetime member of Computer Society of India; an advisory member of IndiaMentor; and certified as a Scrum trainer/coach, XEN for ITIL-F, and APMG for PRINCE-F and PRINCE-P. He is an open source developer, a contributor to TechNet Wiki, and the founder of Ovatic Systems Private Limited. In over the 20 years of his career, he has mentored thousands of students and industry professionals. You can tweet Gaurav on his Twitter handle at @g_arora .

, Introduction to patterns , introduces the concept of patterns. We'll see why patterns are useful and how they should be used in programming. The book will explore the difference between design principles, patterns, and idioms. It will present a hierarchical overview of design patterns, talk a bit about anti-patterns, and finish with a description of some important design principles.

, Singleton, Dependency Injection, Lazy Initialization, and Object Pool , covers four patterns from the creational group. The chapter will firstly look into the singleton pattern, which makes sure that a class has only one instance. Next in line, the dependency injection pattern makes program architecture more flexible and appropriate for unit testing. In the second half, the chapter explores two optimization patterns. The lazy initialization pattern saves time and resources, while the object pool pattern speeds up creation of objects.

, Factory Method, Abstract Factory, Prototype, and Builder , examines four more creational patterns. The factory method pattern simplifies creation of dependent objects. The concept can be extended into the abstract factory pattern, which functions as a factory of factories. The prototype pattern is used to create copies of objects. Last in this group, the builder pattern separates instructions for creating an object from its representation.

, Composite, Flyweight, Marker Interface, and Bridge , covers four patterns from the structural group. The composite pattern allows client code to treat simple and complex objects the same. The flyweight pattern can be used to minimize memory usage by introducing data sharing between objects. The marker interface allows us to unleash a new level of programming power by introducing metaprogramming. The bridge pattern helps us separate an abstract interface from its implementation.

, Adapter, Proxy, Decorator, and Facade , explores four more structural patterns. The adapter pattern helps in adapting old code to new use cases. The proxy pattern wraps an objects and exposes an identical interface to facilitate caching, remoting, and access control, among other things. The decorator pattern specifies how the functionality of existing objects can be expanded, while the facade pattern shows us how to create a simplified view of a complex system.

, Nullable Object, Template Method, Command, and State