@pandino/pandino

The core Pandino runtime: an OSGi-style service registry, bundle system, and built-in services for building modular TypeScript applications. Services discover each other dynamically at runtime instead of being statically wired at compile time.

Where it fits in the Pandino ecosystem

 @pandino/decorators            @pandino/rollup-bundle-plugin
 (declare components) ──┐         (auto-package bundles)
                        ▼                     │
              ┌──────────────────────────┐    │
              │   @pandino/pandino       │ ◀──┘
              │   • Service Registry     │
              │   • Bundle Lifecycle     │
              │   • EventAdmin           │     @pandino/react-hooks
              │   • ConfigurationAdmin   │ ──▶ (consume services in React)
              │   • LogService           │
              │   • SCR (runtime)        │
              └──────────────────────────┘

This package is the heart of any Pandino application. Every other package either produces artifacts it consumes (decorators, rollup plugin) or provides an adapter layer to interact with it (react-hooks).

Installation

npm install @pandino/pandino reflect-metadata

If you plan to use decorators, also install @pandino/decorators:

npm install @pandino/decorators

Import reflect-metadata once at your application's entry point:

import 'reflect-metadata';

TypeScript configuration

Enable decorators and metadata emission in tsconfig.json:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

Core concepts

Services and service references

A service is any object registered in Pandino's central registry under one or more interface names. Consumers don't import service implementations directly — they look them up by interface, optionally filtering by properties.

| Concept | What it is | Analogy | | ----------------------- | ------------------------------------------- | --------------------------- | | Service | The object that does the work | A person you want to call | | Service Reference | A handle used to look up and release access | The phone-book entry | | Service Registration| Handle returned when you publish a service | Your listing in the book |

Bundles

A bundle is a self-contained module with its own lifecycle (install, start, stop, uninstall). Each bundle can publish services, consume services, and register event listeners through a BundleContext. Bundles are the unit of modularity in Pandino.

Dynamic dependencies

Services can appear and disappear at runtime. Dependents are wired automatically as soon as their requirements become available — bundle start-up order does not matter.

Declarative services (SCR)

The Service Component Runtime activates classes annotated with @Component (from @pandino/decorators) and resolves their @Reference dependencies automatically. This eliminates the boilerplate of manual registerService() calls.

Quick start

1. Bootstrap the framework

import 'reflect-metadata';
import { OSGiBootstrap, LogLevel } from '@pandino/pandino';

const bootstrap = new OSGiBootstrap({
  frameworkLogLevel: LogLevel.INFO,
});

const framework = await bootstrap.start();
const context = framework.getBundleContext();

2. Register and consume a service imperatively

interface GreetingService {
  sayHello(name: string): string;
}

class SimpleGreetingService implements GreetingService {
  sayHello(name: string): string {
    return `Hello, ${name}!`;
  }
}

// Publish
const registration = context.registerService('GreetingService', new SimpleGreetingService());

// Look up
const ref = context.getServiceReference<GreetingService>('GreetingService')!;
const service = context.getService(ref)!;
console.log(service.sayHello('World'));

// Clean up
context.ungetService(ref);
registration.unregister();

3. Or declare a component with decorators

import { Component, Service, Reference, Activate } from '@pandino/decorators';
import type { LogService } from '@pandino/pandino';

@Component({ name: 'greeting.service', immediate: true })
@Service({ interfaces: ['GreetingService'] })
export class GreetingServiceImpl implements GreetingService {
  @Reference({ interface: 'LogService' })
  private logger!: LogService;

  @Activate
  activate(): void {
    this.logger.info('GreetingService ready');
  }

  sayHello(name: string): string {
    return `Hello, ${name}!`;
  }
}

Decorated classes are activated by the SCR when they are included in a bundle. See the @pandino/decorators and @pandino/rollup-bundle-plugin documentation for how to ship them as bundles.

Service properties and LDAP filters

Services carry metadata. Consumers can select specific implementations using LDAP filter expressions:

context.registerService('DatabaseService', new MySQLService(), {
  'db.type': 'mysql',
  'db.host': 'localhost',
  'service.ranking': 100,
});

const refs = context.getServiceReferences<DatabaseService>('DatabaseService', '(db.type=mysql)');

Common filter forms:

| Filter | Matches | | --------------------------------------- | ---------------------------------- | | (db.type=mysql) | MySQL database services | | (service.ranking>=100) | High-priority services | | (&(db.host=localhost)(db.port>=3000)) | Local services on ports ≥ 3000 | | (\|(category=urgent)(priority=1)) | Urgent OR priority-1 services |

When multiple services are registered under the same interface, the one with the highest service.ranking wins by default.

Built-in services

These services are registered by the framework itself and are available through the bundle context as soon as it is started.

LogService

Centralised logging with bundle-aware context.

const logRef = context.getServiceReference<LogService>('LogService')!;
const logger = context.getService(logRef)!;

logger.info('Server starting', undefined, { port: 8080 });

EventAdmin

Topic-based publish–subscribe messaging.

import { EventAdmin, Event } from '@pandino/pandino';

const eventAdmin = context.getService(context.getServiceReference<EventAdmin>('EventAdmin')!)!;

// Publish
eventAdmin.sendEvent(new Event('user/login', { userId: '123' }));

// Subscribe
context.registerService('EventHandler', {
  handleEvent: (event) => console.log(event.getTopic(), event.getProperty('userId')),
}, {
  'event.topics': 'user/*',
});

ConfigurationAdmin

Runtime configuration updates delivered to ManagedService instances.

import type { ConfigurationAdmin, ManagedService } from '@pandino/pandino';

const configAdmin = context.getService(context.getServiceReference<ConfigurationAdmin>('ConfigurationAdmin')!)!;

const config = await configAdmin.getConfiguration('database.connection');
await config.update({ host: 'localhost', port: 5432 });

// Services can receive updates by implementing ManagedService
class DatabaseService implements ManagedService {
  updated(props: Record<string, any> | null): void {
    if (props) this.reconnect(props);
  }
}
context.registerService('DatabaseService', new DatabaseService(), {
  'service.pid': 'database.connection',
});

ServiceTracker

A helper that tracks the availability of services matching an interface or filter.

import { ServiceTracker } from '@pandino/pandino';

const tracker = new ServiceTracker<DatabaseService>(context, 'DatabaseService', {
  addingService: (ref) => context.getService(ref),
  removedService: (ref) => context.ungetService(ref),
});

tracker.open();
const current = tracker.getService();

ServiceComponentRuntime (SCR)

Activates and manages declaratively defined components. You usually don't interact with it directly — bundles register their components via SCR automatically. For manual control:

import type { BundleActivator, BundleContext, ServiceComponentRuntime } from '@pandino/pandino';

const activator: BundleActivator = {
  async start(context: BundleContext) {
    const scr = context.getService(context.getServiceReference<ServiceComponentRuntime>('ServiceComponentRuntime')!)!;
    const bundleId = context.getBundle().getBundleId();
    await scr.registerComponent(GreetingServiceImpl, bundleId);
  },
};

Writing a bundle

A bundle is a plain module whose default export describes itself:

import type { BundleActivator, BundleContext } from '@pandino/pandino';

class DatabaseService {
  query(sql: string) { /* ... */ }
}

const activator: BundleActivator = {
  async start(context: BundleContext) {
    context.registerService('DatabaseService', new DatabaseService());
  },
  async stop() {
    // optional manual cleanup; services registered via the context are released automatically
  },
};

export default {
  headers: {
    bundleSymbolicName: 'com.example.database',
    bundleVersion: '1.0.0',
    bundleName: 'Database Bundle',
  },
  activator,
  components: [
    // classes decorated with @Component — optional
  ],
};

Bundles can be loaded at startup by passing them to the bootstrap, installed via context.installBundle(), or produced automatically by the @pandino/rollup-bundle-plugin.

Fragment bundles

A fragment is a bundle that attaches to a host and contributes components or resources without its own lifecycle. Typical uses: localisation packs, platform-specific overrides, theming.

export default {
  headers: {
    bundleSymbolicName: 'com.example.database.german',
    bundleVersion: '1.0.0',
    fragmentHost: 'com.example.database',
  },
  activator: { start: async () => {}, stop: async () => {} },
  components: [{ name: 'GermanTranslations', translations: {/* ... */} }],
};

More details in the Fragment Pattern documentation.

Recommended patterns

Common architectural patterns used with Pandino bundles:

• Extender pattern — observe other bundles and react to their metadata.
• Whiteboard pattern — collect contributions as services instead of plugin registries.
• Fragment pattern — attach to a host bundle.
• Creating decorator extenders — add your own decorator-driven behaviours.

Public API cheatsheet

| Export | Purpose | | ------------------------------ | ------------------------------------------------------ | | OSGiBootstrap | Start and stop the framework | | OSGiFramework | The running framework instance | | BundleContext | Register / look up services, install bundles | | Bundle, BundleActivator | Bundle lifecycle model | | ServiceReference<T> | Handle used to look up and release a service | | ServiceRegistration<T> | Handle to unregister or update a registered service | | ServiceTracker<T> | Tracks service availability with customiser callbacks | | EventAdmin, Event, EventHandler | Publish/subscribe messaging | | ConfigurationAdmin, ManagedService, ManagedServiceFactory | Runtime configuration | | LogService, LogLevel | Framework-provided logger | | ServiceComponentRuntime, ComponentContext | Declarative-service runtime | | BUNDLE_STATES, SERVICE_EVENT_TYPES | Lifecycle / event enumerations | | getDecoratorInfo(ClassRef) | Inspect decorator metadata on a component class |

Related packages

• @pandino/decorators — Decorator-based component declarations.
• @pandino/rollup-bundle-plugin — Package your source files into Pandino bundles at build time.
• @pandino/react-hooks — Use Pandino services from React components.

License

Eclipse Public License - v 2.0