In this part, I will discuss the core design patterns that can help you build better software in frontend development.
Table of contents
Open Table of contents
Design Patterns in Frontend Development
Design patterns aren’t the end goal of frontend development; they are tools that you may choose to use. These patterns have been developed to address specific challenges and characteristics unique to the application layer. You can either rely on these well-tested solutions or ignore them at your own risk, potentially incurring the costs of that decision.
Why Use Design Patterns?
State Management: Frontend often involves managing dynamically changing application states due to user interactions and backend data. Patterns like Flux or Redux organize and predict state changes, promoting a unidirectional data flow. This structure supports easier tracking, debugging, and testing of application state.
Event Handling: Frontend masters must handle events triggered by users (like clicks or scrolls) and data streams from external sources. Patterns such as Observer or Publish/Subscribe allow for decentralized event management, reducing the need for complex component dependency chains.
Asynchronicity: Browsers operate in an inherently asynchronous, event-driven environment. Managing multiple tasks like UI rendering, user event processing, and JavaScript execution simultaneously necessitates asynchronous code, especially for operations like network requests or file I/O.
Complex Projects: Modern frontend applications feature extensive modules and components, often incorporating significant business logic. Patterns like Composition, Module, or Factory facilitate modular code design, enhancing reusability and maintainability. This modularity is essential for creating organized, scalable, and maintainable applications, especially in large-scale projects.
Choosing the Right Tech Stack: Understanding frontend design patterns can greatly assist in selecting the appropriate tools for specific problems. Whether it’s choosing between Virtual DOM, RxJS, or Signals for reactivity, or deciding on frameworks with or without dependency injection, knowing these patterns enables more informed decisions, beyond merely following trends.
Code Refactoring
As you advance, you’ll discover more patterns and best practices that significantly enhance project quality. You might wonder whether to introduce these improvements gradually or undertake a comprehensive refactoring from the top of the component tree. Each approach has its merits and challenges:
Top-Down Approach
- Pros:
- Allows for significant architectural and tech stack changes.
- Current application operations remain uninterrupted.
- Part of the team can focus on a new, independent project.
- Cons:
- Long project duration from initiation to production deployment.
- Necessitates maintaining two coherent application versions.
- High risk of project abandonment before reaching production.
Bottom-Up Approach
- Pros:
- Enables continuous and incremental application improvements.
- Minimizes the risk of divergence between two application versions.
- Suitable for smaller teams with limited resources.
- Cons:
- May not address significant architectural flaws.
- Focus on localized improvements could obscure overall project perspective.
- Time invested in local changes may not yield immediate user benefits.
Which Approach to Choose?
Agile practices typically favor a bottom-up approach, allowing for more flexible change implementation and requiring less communication overhead than a top-down approach. The component model, a standard in modern frontend development, supports changes in this manner, setting a clear boundary for refactoring efforts.
Radical changes, such as switching frameworks or overhauling application foundations (common in top-down approaches), involve greater risks, more difficult discussions with superiors, and a potentially unreachable finish line. Thus, many experienced developers prefer to avoid these radical steps, opting instead for gradual enhancements that secure progress and stability.
References
What is ECMA Script? - Mozilla Developer Network Dependency Inversion Principle Explained - Blog LogRocket Commonsense Programming Practices - Grug Brain Understanding the Philosophy of Software Design The Pragmatic Programmer - Andy Hunt and Dave Thomas Component structure vs complexity