Master React: Best Practices for Designing High-Performance Components
The world of web development is moving at breakneck speed. At the heart of many of the most powerful and engaging web applications is React.js.
React, a JavaScript library that we have already seen in previous articles is one of the most popular JavaScript libraries for building interactive and dynamic user interfaces. One of the main features of React is its focus on creating reusable components. These components can be combined to build complex applications.
However, creating components in React effectively and sustainably requires following some best practices. In this article, we’re going to dive into the depths of React. We’ll explore the key strategies that will help you create high-performing components and build faster, more maintainable applications. Discover the best practices!
Maintaining Consistency in your Components and Using Design Patterns
React offers several ways to create functional components in an application. Some of these include arrow functions, function declarations, and function expressions. Each of these ways is valid, but it is critical to maintain consistency in your code when choosing a convention for declaring your components.
Inconsistency in the way you create your components can make your code difficult to read. This becomes more problematic as your project grows and you need to perform maintenance.
It is essential to follow design patterns to keep your code organized, easy to read, and maintain. One of the most important patterns is the separation of presentation logic and business logic into components.
This not only improves readability but also facilitates unit testing and makes it easier to make changes.
Distinguishing between Presentation Logic and Business Logic
- Presentation Logic: This refers to the part of the component that is in charge of how it looks and presents itself in the user interface. It includes JSX elements, styles, and anything related to the visual representation of the component.
- Business Logic: This refers to the part of the component that handles the underlying operations and calculations, such as data manipulation, API calls, and state management. This logic is independent of how the component is represented.
Categorization into Containers and Submission Components
This pattern is based on the idea of dividing your components into two categories: containers and presentations.
Containers take care of business logic and state management. Presentation components, on the other hand, focus on how the user interface looks and is represented.
This makes it easy to reuse and test presentation components without worrying about the underlying logic.
Enhancing Components with High Order Components (HOC)
HOCs are functions that take a component and return a new component with additional functionality. This is useful for adding common logic to several components.
<!-- Arrow Functions -->
import React from 'react';
const MyComponent = () => {
return <div>My Component</div>;
};
export default MyComponent;
<!-- Function Declarations -->
import React from 'react';
function MyComponent() {
return <div>My Component</div>;
}
export default MyComponent;
<!-- Function Expressions -->
import React from 'react';
const MyComponent = function() {
return <div>My Component</div>;
};
export default MyComponent;Promoting Modularity and Reuse of Components
A fundamental principle of React is the division of the user interface into small, reusable components. This approach promotes the creation of more efficient and maintainable applications by breaking down the user interface into smaller, more manageable parts. Each component should have a single responsibility and be easy to understand. This modularity not only improves code readability but also facilitates reuse in different parts of the application, which saves time and effort in development.
By breaking down your UI into smaller components, you are following React development best practices. This allows you to build applications that are scalable and easy to maintain. Each component becomes an independent unit that can be tested and improved separately, which simplifies the development and debugging process.
Instead of having one massive code file containing all the logic of your application, you can create a modular structure of components that communicate with each other through properties (props). Each component focuses on a specific task and becomes a reusable tool that you can leverage in different parts of your application.
Benefits of the Single Responsibility Principle in React
One of the fundamental principles in React application development is the “Single Responsibility Principle”. This principle dictates that each component in your application should have a single responsibility, focusing on a specific functionality or task. By following this principle, components become more reusable, easier to understand, and less error-prone. Let’s see how this principle applies to creating components in React.
When a component has a single responsibility, there are several benefits:
- Reusability: Components can be used in different parts of the application, as their functionality is clear and specific.
- Maintainability: Components are easier to maintain because changes or fixes are applied to a specific part of the application.
- Readability: Code is more readable as components have a clear purpose and do not perform multiple tasks.
- Debugging: Bugs are easier to locate and fix when a component has a single responsibility.
Example of Single Responsibility
Let’s say you are building an e-commerce application in React. Here is an example of how the single responsibility principle is applied:
- “Product” component: this component is exclusively responsible for displaying information about a product, such as its name, price and description. It does not handle shopping interactions or shopping cart management.
- Shopping Cart” Component: This component is dedicated solely to managing the products that are added to or removed from the shopping cart. It is not concerned with the visual representation of the products.
- Component “Buy Button”: This component has the sole responsibility of managing the action of adding a product to the cart.
Securing Trust with Property Types and Defaults
It is essential to define properties (property types) and defaults (default props) to ensure the reliability of your components in React. Prop types validate the expected types of props, allowing you to catch potential errors early. On the other hand, default props provide fallback values if a prop is not explicitly passed, preventing unexpected behavior.
It is critical to understand the difference between props and states in React. Props are static data that are passed between components and are immutable, i.e. they do not change within the component. State, on the other hand, is used to manage dynamic data within a component. It represents the internal state of the component. This allows it to respond to user interactions, events, or changes in its internal logic.
Simplifying the Code with the Local State
If a component needs to maintain an internal state, it is recommended to use the local state (state). Instead of a global state (Redux, Context) whenever possible. This simplifies the code and improves scalability, as the local state is more bounded and easier to handle on specific components.
Ensuring Quality with React Testing
Testing is fundamental in React component development. Here are some best practices to consider:
- Use Jest and Cypress
Use libraries like Jest and Cypress to write unit and end-to-end tests. Jest is great for logic and functions, while Cypress is perfect for user interactions. - Test Props and State
Make sure your components handle props and state correctly. This helps identify bugs that may go unnoticed in the user interface. - Test User Interactions
Verify that your components properly handle user actions and events. This ensures a friendly and responsive user experience. - Automate your Testing
Automating testing ensures consistency and prevents errors in future updates.
Optimizing Performance with React.memo and shouldComponentUpdate
To achieve performance, it is essential to avoid unnecessary rendering of your components. Two key techniques to achieve this are React.memo (for functional components) and shouldComponentUpdate (for class components).
React.memo for Functional Components
When working with functional components in React, React.memo is your ally. This higher-order function (HOC) memorizes the result of a functional component and returns it when the props haven’t changed. This means that if a part of your application uses components that rarely change, you can use React.memo to avoid unnecessary re-rendering.
shouldComponentUpdate for Class Components
For class components in React, you can take advantage of the shouldComponentUpdate method to control when a rendering should be performed. This method takes the new props and new state as arguments and returns a boolean value indicating whether or not the rendering should take place.
<!-- REACT MEMO -->
import React from 'react';
const MiComponente = React.memo(({ data }) => {
// Renderizado basado en las props data
return <div>{data}</div>;
});
<!-- shouldComponentUpdate -->
import React, { Component } from 'react';Moving Forward with Confidence in the React World
In conclusion, by following these best practices for component design in React, you are on the right path to creating more robust, maintainable, and efficient applications. Modularity, single accountability, proper handling of props and state, choosing a consistent styling approach, and implementing robust testing are fundamental to developing high-quality components.