Utility Functions - Overview

Status: ✅ Fully documented

Introduction

The p2d2 application uses an extensive collection of utility functions organized into various categories. These utilities form the technical foundation for the entire application, providing reusable functions for data processing, API integrations, event handling, and more.

Categories

🗺️ Map & Geo Utilities

• CRS Management - Coordinate transformation and projection management
• Layer Management - Map layer and interaction management
• Map State - Central state management for the map
• Map Navigation - Navigation and zoom functions

📡 API & Service Utilities

• WFS Integration - GeoServer WFS client with authentication
• WFS Layer Management - Dynamic WFS layer management
• Event System - Robust event handling with retry mechanism

🏗️ Core Utilities

• Kommune Utilities - Data management for municipalities
• Click Handler - Touch-optimized interaction handling
• Logger - Consistent logging infrastructure
• Storage Management - Persistence and state management

🔧 Integration & Build

• Polygon Sync Plugin - Automatic polygon synchronization
• Type Definitions - TypeScript interfaces and types

Architectural Principles

1. Separation of Concerns

Each utility category has clearly defined responsibilities and is independent of other modules.

2. Reusability

Utilities are designed to be reusable in different contexts.

3. Error Handling

Robust error handling with sensible fallbacks and detailed logging.

4. Type Safety

Comprehensive TypeScript support with clearly defined interfaces.

5. Performance

Optimized implementations with caching and efficient algorithms.

Usage Example

// Typical usage of utilities
import { getAllKommunen } from '../utils/kommune-utils';
import { dispatchKommunenFocus } from '../utils/events';
import { logger } from '../utils/logger';

// Load municipalities
const kommunen = await getAllKommunen();

// Trigger event
dispatchKommunenFocus({
  center: [6.95, 50.94],
  zoom: 12,
  slug: 'koeln'
});

// Logging
logger.info('Utilities initialized successfully');

Best Practices

1. Import Guidelines

// ✅ Correct - Named imports for specific functions
import { getAllKommunen, getKommuneBySlug } from '../utils/kommune-utils';

// ❌ Avoid - Wildcard imports
import * as kommuneUtils from '../utils/kommune-utils';

2. Error Handling

// ✅ Correct - Explicit error handling
try {
  const kommune = await getKommuneBySlug('koeln');
} catch (error) {
  logger.error('Error loading municipality', error);
  // Implement fallback logic
}

3. Performance Optimization

// ✅ Correct - Use caching
const kommunen = await getAllKommunen(); // Will be cached

// ✅ Correct - Event throttling
dispatchThrottledEvent('kommunen:focus', detail, 200);

Testing

All utilities are designed for easy testability:

// Example unit test
describe('Kommune Utilities', () => {
  it('should load all kommunen', async () => {
    const kommunen = await getAllKommunen();
    expect(kommunen).toBeInstanceOf(Array);
    expect(kommunen.length).toBeGreaterThan(0);
  });
});

Further Documentation

• CRS & Coordinate Utilities
• Layer Management & Interaction
• Storage & State Management
• Event System & API Integration
• Kommune Data Management
• WFS Integration

Changelog

v1.0.0 (2024-12-19)

• ✅ Complete documentation of all utility categories
• ✅ TypeScript interfaces for all main modules
• ✅ Robust error handling implementations
• ✅ Performance optimizations with caching