Coordinator Interface

A service state coordinator and log collector interface, built on top of an event-driven logging system.

Installation

npm install @silyze/coordinator @silyze/logger @silyze/typed-event-target

Overview

The Coordinator class provides:

• Typed events for logs (LogEvent) and service status changes (StatusEvent).
• A scoped logger (CoordinatorLogger) that emits LogEvent instances.
• Abstract methods to manage and observe service states.

Use it as a base class for any component that needs to coordinate multiple services and collect their logs in a type-safe, event-driven fashion.

Basic Usage

import {
  Coordinator,
  ServiceStatus,
  CoordinatorLog,
} from "@silyze/coordinator";

class MyCoordinator extends Coordinator {
  get url() {
    return "https://api.example.com";
  }

  async setServiceStatus(
    resourceId: string,
    service: string,
    status: ServiceStatus
  ) {
    // update internal state or remote store
    this.dispatchEvent(new StatusEvent(resourceId, service, status));
  }

  async getServiceStatus(
    resourceId: string,
    service: string
  ): Promise<ServiceStatus | null> {
    // retrieve state
    return null;
  }

  async waitForServiceStatus(
    resourceId: string,
    service: string,
    expectedStatus: ServiceStatus
  ) {
    // optional: wait until a StatusEvent matches expectedStatus
  }
}

const coordinator = new MyCoordinator();

// Listen for logs
coordinator.addEventListener("log", (evt) => {
  console.log(`[${evt.log.severity}] ${evt.log.area}: ${evt.log.message}`);
});

// Listen for status changes
coordinator.addEventListener("status", (evt) => {
  console.log(`Service ${evt.service} is now ${evt.status}`);
});

// Create a scoped logger
const logger = coordinator.createLogger("resource-123");
logger.log({
  severity: "info",
  area: "startup",
  message: "Coordinator started",
});

// Emit a service status
await coordinator.setServiceStatus("resource-123", "database", "running");

API Reference

Types

• ServiceStatus: "running" | "stopped"

• CoordinatorLog:

  interface CoordinatorLog {
    context: LoggerContext;
    severity: LogSeverity;
    message: string;
    area: string;
    object?: unknown;
  }

Classes

class LogEvent extends Event

Emitted when a log entry is created.

• Properties:

  • resourceId: string | undefined
  • log: CoordinatorLog
  • shouldDistribute: boolean

class StatusEvent extends Event

Emitted when a service status changes.

• Properties:

  • resourceId: string
  • service: string
  • status: ServiceStatus

abstract class Coordinator implements TypedEventTarget<LogEvent | StatusEvent, "log" | "status">

Base class for coordinating services and collecting logs.

• Event Methods:

  • addEventListener(type: "log" | "status", listener): void
  • removeEventListener(type: "log" | "status", listener): void
  • dispatchEvent(event: LogEvent | StatusEvent): boolean

• Abstract Methods (must be implemented):

  • setServiceStatus(resourceId: string, service: string, status: ServiceStatus): Promise<void>
  • getServiceStatus(resourceId: string, service: string): Promise<ServiceStatus | null>
  • waitForServiceStatus(resourceId: string, service: string, expectedStatus: ServiceStatus): Promise<void>
  • get url(): string

• Helper:

  • createLogger(resourceId?: string, ...loggers: Logger[]): Logger

    • Returns a combined logger that emits LogEvents and delegates to any provided Logger instances.