Imagine you’re at a party where frameworks like React, Angular, Vue and Nest are the cool kids everyone wants to hang out with. You’ve probably spent a bunch of time learning the secret handshakes (a.k.a. syntax) to fit in, right?
But here's a fun twist :
The real magic isn’t in the handshakes at all. It’s in the stories and jokes they share. those are the design patterns.
Think of design patterns like the inside jokes of software development. Once you’re in on the joke, everything makes a lot more sense, and you can laugh along with everyone else.
Without knowing the joke, you might find yourself laughing just a bit too late, feeling a bit out of sync.
Imagine how cool it would be to not just know the handshakes but to get the jokes and stories too. That's what understanding design patterns do for you.
Intro
What are they
In software development, design patterns are established solutions to frequently encountered challenges faced when designing software. They act as reusable blueprints that provide proven approaches to common problems, promoting flexibility, maintainability, and efficiency in your code.****
Design patterns are not ready-made pieces of code that can be directly inserted into a program; instead, they are templates or guidelines that describe how to solve a problem in different situations.
Are they even relevant anymore?
Design patterns remain highly relevant in modern software development for several reasons. They provide time-tested solutions to common problems, promote best practices in software design, and facilitate communication among developers by providing a common terminology. Despite the evolution of programming languages and development tools, the fundamental challenges of designing flexible, maintainable, and scalable software systems persist, making design patterns invaluable.
They promote :
ℹ️ Code Reusability and Scalability: ✅ By providing tested and proven development paradigms, design patterns facilitate the reuse of code, making it easier to scale and maintain software projects.
ℹ️ Solutions to Common Problems: ✅ Design patterns offer solutions to issues that developers frequently face, saving the time and effort required to come up with new solutions.
ℹ️ Best Practices: ✅ They encapsulate best practices that have been evolved over time by experienced developers, ensuring that software is built using industry-standard methodologies.
ℹ️ Improved Communication: ✅ Design patterns provide a common vocabulary for developers, which simplifies communication about software designs. When a developer says they’re using a Singleton pattern, for instance, other developers will immediately understand the design choice without needing detailed explanations.
Language Agnostic
Technically, design pattern are language agnostic, meaning you can pretty much implement them regardless of your language of choice.
While design patterns are language-agnostic concepts, their influence is evident in the design of many programming languages and libraries.
Some languages and libraries have incorporated patterns directly into their architecture, making it easier for developers to implement these patterns without having to write boilerplate code
🔖 **Directly into the language JavaScript ✅ Module Pattern: JavaScript modules (especially with ES6 and beyond) encapsulate functionality, promoting loose coupling and high cohesion, a fundamental principle of the Module pattern. This pattern is extensively used for structuring large-scale JavaScript applications.
✅ **Promise**: The Promise object in JavaScript is an implementation of the Promise pattern (related to the State and Strategy patterns), which facilitates asynchronous programming by representing a value that may be available now, in the future, or never.
🔖 React (Library): ✅ Composite Pattern: React utilizes the Composite pattern allowing developers to compose components into tree structures to represent part-whole hierarchies. This makes it easier to develop and manage complex UIs. ✅ Observer Pattern: The use of state and props in React can be seen as an implementation of the Observer pattern, where changes in state or props trigger re-rendering of components.
🔖 Redux (Library): ✅ Singleton Pattern: In Redux, the store is typically implemented as a Singleton, ensuring there is a single source of truth for the application’s state across the entire app.
Now that i have convinced you of how patters are important, let's explore few patters together. but before that, I highly recommend reading more about SOLID Principles. They provide foundations of writing clean code, and they are constantly referenced in design patterns.
SOLID Principle
TL;DR
Below is a quick summary on SOLID Principles,
The SOLID principles are not design patterns but rather a set of five guidelines intended to improve the design, maintainability, and scalability of software systems. They are foundational concepts in object-oriented design that encourage developers to create more manageable and robust code. Each letter in “SOLID” stands for a principle:
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S - Single Responsibility Principle (SRP): A class should have only one reason to change, meaning it should have only one job or responsibility. This principle encourages modularity and makes the system easier to understand and maintain.
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O - Open/Closed Principle (OCP): Software entities (classes, modules, functions, etc.) should be open for extension but closed for modification. This means you should be able to add new functionality without changing existing code, which helps in maintaining stability while the software evolves.
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L - Liskov Substitution Principle (LSP): Objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program. This principle ensures that a subclass can stand in for its superclass.
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I - Interface Segregation Principle (ISP): Clients should not be forced to depend upon interfaces they do not use. This principle advocates for fine-grained interfaces that are client-specific rather than one general-purpose interface, reducing the impact of changes and improving code robustness.
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D - Dependency Inversion Principle (DIP): High-level modules should not depend on low-level modules. Both should depend on abstractions. Additionally, abstractions should not depend on details; details should depend on abstractions. This principle leads to the decoupling of software modules, making them more reusable and modular.