Extension System

The KIMU extension system provides a powerful, modular architecture that allows developers to create reusable, independent components that can be dynamically loaded and integrated into applications.

Overview

The extension system enables:

• Modular development with independent, reusable components
• Dynamic loading of extensions at runtime
• Dependency management between extensions
• Lifecycle management with automatic cleanup
• Hot reloading during development
• Version management and compatibility checking

Key Concepts

Extensions vs Components

• Extensions are packaged, distributable modules that can contain multiple components
• Components are individual Web Components that implement specific functionality
• Extensions can bundle components, assets, styles, and configuration together

Extension Architecture

Extension Package
├── component.ts        # Main entry point
├── manifest.json      # Extension metadata
├── assets/           # Static resources
│   ├── styles.css
│   ├── images/
│   └── fonts/
├── components/       # Additional components
├── services/         # Business logic
└── types/           # TypeScript definitions

Extension Lifecycle

1. Discovery - Extensions are found through manifest files
2. Loading - Extension code is dynamically imported
3. Registration - Components are registered with the DOM
4. Initialization - Extension setup and configuration
5. Runtime - Active use and inter-extension communication
6. Cleanup - Resource cleanup and unloading

Core Features

Dynamic Loading

Extensions are loaded on-demand to optimize application startup time:

const extensionManager = KimuExtensionManager.getInstance();

// Load specific extension
await extensionManager.loadExtension('data-visualization');

// Load all extensions
await extensionManager.loadAllExtensions();

Dependency Management

Extensions can declare dependencies that are automatically resolved:

{
  "tag": "advanced-chart",
  "dependencies": ["chart-library", "data-processor"],
  "version": "2.1.0"
}

Asset Management

Extensions can bundle assets that are managed by the framework:

import { KimuAssetManager } from '../core/kimu-asset-manager';

const assetManager = KimuAssetManager.getInstance();
const iconUrl = await assetManager.getAsset('my-extension/icon.svg');

Inter-Extension Communication

Extensions communicate through events and shared state:

// Extension A
this.dispatchEvent(new CustomEvent('data-updated', {
  detail: { newData: processedData }
}));

// Extension B
document.addEventListener('data-updated', (event) => {
  this.updateVisualization(event.detail.newData);
});

Extension Types

UI Extensions

Provide user interface components and widgets:

• Navigation components
• Form controls
• Data visualization widgets
• Modal dialogs and overlays

Service Extensions

Provide business logic and data processing:

• API clients
• Data transformers
• Authentication services
• Notification systems

Integration Extensions

Connect with external systems and services:

• Third-party API integrations
• Database connectors
• Analytics providers
• Payment processors

Utility Extensions

Provide common functionality and tools:

• Date/time utilities
• Validation libraries
• Formatting helpers
• Development tools

Development Workflow

1. Create Extension Structure

mkdir src/extensions/my-extension
cd src/extensions/my-extension
touch component.ts

2. Define Component

import { KimuComponent } from '../../decorators/kimu-component';

@KimuComponent({
  tag: 'my-extension',
  name: 'My Extension',
  version: '1.0.0'
})
export class MyExtension extends HTMLElement {
  connectedCallback() {
    this.innerHTML = '<h1>Hello from My Extension!</h1>';
  }
}

3. Update Manifest

{
  "tag": "my-extension",
  "path": "my-extension",
  "name": "My Extension",
  "version": "1.0.0",
  "description": "A sample extension",
  "author": "Developer"
}

4. Build and Test

npm run build:extension my-extension
npm run test:extension my-extension

Configuration and Customization

Extension Configuration

Extensions can be configured through the manifest or runtime:

{
  "tag": "configurable-widget",
  "config": {
    "theme": "dark",
    "maxItems": 10,
    "autoRefresh": true
  }
}

Runtime Configuration

const config = this.getExtensionConfig();
const theme = config.theme || 'light';
const maxItems = config.maxItems || 5;

Environment-Specific Loading

// Load different extensions based on environment
const extensions = process.env.NODE_ENV === 'development' 
  ? ['debug-tools', 'performance-monitor']
  : ['analytics', 'error-tracker'];

for (const ext of extensions) {
  await extensionManager.loadExtension(ext);
}

Performance Considerations

Lazy Loading

Extensions are loaded only when needed:

• Initial page load includes only critical extensions
• Additional extensions load on user interaction
• Background loading for predictive loading

Code Splitting

Extensions are built as separate bundles:

• Reduces main bundle size
• Enables parallel loading
• Supports caching strategies

Resource Optimization

• Asset compression and optimization
• Tree shaking for unused code
• Shared dependency management

Security and Isolation

Sandboxing

Extensions run in isolated environments:

• Shadow DOM encapsulation
• Scoped CSS and JavaScript
• Controlled API access

Permission System

Extensions declare required permissions:

{
  "permissions": ["storage", "network", "notifications"]
}

Content Security Policy

Extensions must comply with CSP rules:

• No inline scripts or styles
• Restricted external resource loading
• Secure communication channels

Documentation Sections

Creating Extensions

Step-by-step guide to building your first extension with complete examples and best practices.

Extension Lifecycle

Detailed explanation of the extension lifecycle with hooks and event handling.

Extension Manifest

Complete reference for extension manifest configuration and metadata.

Build and Deployment

Build system configuration, optimization, and deployment strategies.

Best Practices

Comprehensive guide to extension development best practices, patterns, and anti-patterns.

Examples

Simple Extension

@KimuComponent({
  tag: 'weather-widget',
  name: 'Weather Widget'
})
export class WeatherWidget extends HTMLElement {
  async connectedCallback() {
    const weather = await this.fetchWeather();
    this.innerHTML = `
      <div class="weather-widget">
        <h3>${weather.location}</h3>
        <p>${weather.temperature}°C</p>
        <p>${weather.description}</p>
      </div>
    `;
  }

  private async fetchWeather() {
    // Weather API integration
    return {
      location: 'New York',
      temperature: 22,
      description: 'Sunny'
    };
  }
}

Advanced Extension with Dependencies

@KimuComponent({
  tag: 'data-dashboard',
  name: 'Data Dashboard',
  dependencies: ['chart-library', 'data-source']
})
export class DataDashboard extends HTMLElement {
  private chartLib: any;
  private dataSource: any;

  async connectedCallback() {
    // Wait for dependencies
    await this.waitForDependencies();
    
    // Initialize dashboard
    this.setupDashboard();
  }

  private async waitForDependencies() {
    const manager = KimuExtensionManager.getInstance();
    
    // Ensure dependencies are loaded
    if (!manager.isExtensionLoaded('chart-library')) {
      await manager.loadExtension('chart-library');
    }
    
    if (!manager.isExtensionLoaded('data-source')) {
      await manager.loadExtension('data-source');
    }
  }

  private setupDashboard() {
    // Use loaded dependencies
    this.chartLib = window.ChartLibrary;
    this.dataSource = window.DataSource;
    
    this.render();
  }
}

Migration and Versioning

Version Compatibility

Extensions specify compatible framework versions:

{
  "kimuVersion": "^1.0.0",
  "engines": {
    "node": ">=14.0.0"
  }
}

Migration Guides

When updating extensions:

1. Check compatibility with new framework version
2. Update dependencies and APIs
3. Test thoroughly
4. Update documentation

Deprecation Strategy

• Clear deprecation warnings
• Migration path documentation
• Gradual phase-out timeline
• Backward compatibility when possible

The extension system is the heart of KIMU's modularity, enabling developers to create rich, reusable components that can be easily shared and integrated into any KIMU application.

References

• KimuExtensionManager - Core extension management
• KimuComponent Decorator - Component registration
• Pattern Overview - Architectural patterns
• Framework Reference - Complete framework documentation