Book Image

Hands-On Design Patterns with Delphi

By : Primož Gabrijelčič
Book Image

Hands-On Design Patterns with Delphi

By: Primož Gabrijelčič

Overview of this book

Design patterns have proven to be the go-to solution for many common programming scenarios. This book focuses on design patterns applied to the Delphi language. The book will provide you with insights into the language and its capabilities of a runtime library. You'll start by exploring a variety of design patterns and understanding them through real-world examples. This will entail a short explanation of the concept of design patterns and the original set of the 'Gang of Four' patterns, which will help you in structuring your designs efficiently. Next, you'll cover the most important 'anti-patterns' (essentially bad software development practices) to aid you in steering clear of problems during programming. You'll then learn about the eight most important patterns for each creational, structural, and behavioral type. After this, you'll be introduced to the concept of 'concurrency' patterns, which are design patterns specifically related to multithreading and parallel computation. These will enable you to develop and improve an interface between items and harmonize shared memories within threads. Toward the concluding chapters, you'll explore design patterns specific to program design and other categories of patterns that do not fall under the 'design' umbrella. By the end of this book, you'll be able to address common design problems encountered while developing applications and feel confident while building scalable projects.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt


In this chapter, I have explored four basic creational patterns.

The first one was singleton, a pattern used when we need exactly one instance of a class. The chapter looked at a few bad and a few good implementations and explored alternatives.

After that, I switched to the DI pattern, which can sometimes be used to replace a singleton. As DI is incredibly large area, the chapter has focused on basics and explored different injection mechanisms.

The third pattern in this chapter was lazy initialization. The mechanism behind the lazy initialization (the test, create, use idiom) is so simple that most of the time we don't think about this concept as a pattern. It can still be tricky to implement this pattern correctly, and I have pointed to few potential problems and offered a way to overcome them.

For the last pattern in this chapter, I have looked into the object pool. This pattern is used when creating and initializing new object is a costly operation. The object pool represents a storage...