Introduction
As a software engineer, designing object-oriented software is difficult, and designing reusable object-oriented software is much harder. Now you must be thinking, how? So let's try to understand in simple words,
Imagine you're making a virtual zoo. First, you make a basic Animal class. But then, you need to add various animals like lions, elephants, birds, etc. You could make a separate class for each animal, but you notice that you're writing the same code over and over again. This strategy is not only inefficient, but it also makes your code more difficult to manage and modify.
This is where the design patterns come into the picture. Design patterns are proven answers to common software design difficulties. They provide a pattern for structuring your classes in a way that they are more reusable, maintainable, and easy to understand.
History of Design Patterns?
The concept of design patterns has its origins in the field of architecture. In 1977, an architect named Christopher Alexander published a book titled A Pattern Language that suggested using patterns to define good design practices in the domains of urban planning and building architecture. Later, software engineers Kent Beck and Ward Cunningham extended this idea to programming practices.
The concept of design patterns gained momentum with the release of the book Design Patterns: Elements of Reusable Object-Oriented Software in 1994. This book, written by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, collectively known as the Gang of Four (GoF), introduced 23 design patterns and is considered a landmark in the field of software engineering. Since then, design patterns have become a fundamental part of software development. Many more patterns have been recognized and documented, and knowledge of design patterns is now regarded as a critical skill for software developers.
Why Should You Care About Design Patterns?
Design patterns offer numerous benefits to the software developer such as,
- Reusable Solutions: Design patterns provide solid and proven answers to common software design problems. They are considered industry best practices and can be used to reduce challenges that developers frequently experience during everyday programming jobs.
- Communication: Design patterns provide standard terminology and are specific to the problem they solve, making it easier for developers to communicate with each other. When developers talk about a "Singleton" or "Factory" pattern, for example, it's clear what kind of solution they're discussing.
- Efficiency: Design patterns can help to speed up development by giving tested and optimized solutions. This can help to prevent minor flaws that can lead to major problems while also improving code readability and organization.
- Code Maintainability: Design patterns frequently result in more ordered and understandable code, making it easier to read and maintain. They also encourage reuse and can help to avoid code smells or anti-patterns.
- Learning OO Principles: Design patterns can assist developers in better understanding and applying object-oriented design principles like encapsulation, inheritance, and polymorphism.
Types of Design Patterns
Design patterns are broadly classified into three types: creational, structural, and behavioral.
- Creational Patterns deal with object creation methods, attempting to construct things in a manner appropriate to the situation.
- Structural Patterns relate to object composition, or how things interact with one another.
- Behavioral Patterns are used in communications between entities to ensure that they communicate correctly.
| Creational |
Structural |
Behavioral |
| Singleton |
Adapter |
Chain of Responsibility |
| Factory Method |
Bridge |
Command |
| Abstract Factory |
Composite |
Interpreter |
| Builder |
Decorator |
Iterator |
| Prototype |
Facade |
Mediator |
| |
Flyweight |
Memento |
| |
Proxy |
Observer |
| |
|
State |
| |
|
Strategy |
| |
|
Template Method |
| |
|
Visitor |
Design Patterns in Flutter
In the context of Flutter, design patterns can be utilized to overcome typical app development problems. For example, the Singleton pattern can be used to ensure that only one instance of a class exists; the Observer pattern can be used to inform widgets of changes; and numerous state management patterns may be used to efficiently manage an app's state. In the upcoming articles, we will explore these and other design patterns in detail, demonstrating how to implement them in Flutter.
Conclusion
To summarize, as a software developer, you are likely already using some design patterns without realizing it. However, being aware of these patterns may help you write more reusable and maintainable code.
Over the next 23 articles, I'll go over each design pattern in detail, breaking it down into simple, understandable words. So, be ready for an in-depth journey with design patterns. I'll be covering all 23 design patterns from the book Design Patterns: Elements of Reusable Object-Oriented Software. If you like my articles, you can connect with me on LinkedIn and say hello.
If you want to read more about Design Patterns in Flutter, the next articles in this series are listed below.