Component Development

Overview

This section covers advanced component development patterns and techniques for building high-quality, performant UI components in our React Native application. Learn how to create components that are maintainable, testable, and optimized for production use.

What You'll Learn

Master advanced techniques including:

Complex component patterns and composition
Comprehensive testing strategies
Performance optimization techniques
Smooth animation implementations

Development Topics

Component Patterns

Advanced patterns for building flexible, reusable components

Testing Patterns

Comprehensive testing strategies for UI components

Performance Guide

Optimization techniques for fast, responsive components

Animation Patterns

Creating smooth, performant animations in React Native

Key Principles

1. Component Quality

Every component should meet our quality standards:

Type Safety: Full TypeScript coverage with no any types
Accessibility: WCAG 2.1 AA compliance built-in
Performance: Optimized rendering and minimal re-renders
Testing: Comprehensive test coverage including edge cases
Documentation: Clear props documentation and usage examples

2. Development Process

Follow a consistent development process:

Design First: Start with clear requirements and API design
Type Interfaces: Define TypeScript interfaces before implementation
Test-Driven: Write tests alongside or before implementation
Performance Check: Profile and optimize before finalizing
Documentation: Document as you build, not after

3. Code Organization

Maintain consistent structure across all components:

ComponentName/
├── ComponentName.tsx          # Main implementation
├── ComponentName.test.tsx     # Unit tests
├── ComponentName.stories.tsx  # Storybook stories
├── types.ts                   # TypeScript interfaces
├── hooks.ts                   # Component-specific hooks
├── utils.ts                   # Helper functions
├── styles.ts                  # Styled components (if used)
└── index.ts                   # Barrel exports

Common Development Patterns

Composition Over Configuration

Build flexible components through composition:

// ✅ GOOD - Composable
<Card>
  <Card.Header>
    <Card.Title>Product</Card.Title>
    <Card.Actions>
      <IconButton icon="edit" />
    </Card.Actions>
  </Card.Header>
  <Card.Body>Content</Card.Body>
</Card>
 
// ❌ AVOID - Configuration heavy
<Card
  title="Product"
  showActions
  actionButtons={['edit']}
  body="Content"
/>

Custom Hooks for Logic

Extract reusable logic into custom hooks:

// ui/patterns/Form/hooks.ts
export function useFormValidation(rules: ValidationRules) {
  const [errors, setErrors] = useState<ValidationErrors>({});
  const [touched, setTouched] = useState<Set<string>>(new Set());
  
  const validate = useCallback((values: FormValues) => {
    // Validation logic
  }, [rules]);
  
  return { errors, touched, validate, setTouched };
}

Performance by Default

Build performance into components from the start:

// Use memo for expensive components
export const ExpensiveList = memo(({ items }: Props) => {
  return items.map(item => <Item key={item.id} {...item} />);
});
 
// Use callbacks for stable references
const handlePress = useCallback(() => {
  // Handle press
}, [dependencies]);