Attaching a Transport

How Transport Attachment Works

When you call registerServer(registration), the EdgeStream facade immediately calls createTransport(registration.transportConfig) and passes the result to the Server constructor. You never instantiate transports directly in application code.

// Internal — EdgeStream.registerServer()
registerServer(registration: IServerRegistration): void {
  const transport = createTransport(registration.transportConfig); // factory
  const server = new Server(registration, transport);
  this.servers.set(registration.id, server);
}

TransportFactory

// TransportFactory selects the implementation based on type
export function createTransport(config: TransportConfig): ITransport {
  const id = generatePrefixedId('transport');
  switch (config.type) {
    case 'signalr':      return new SignalRTransport(id, config);
    case 'websocket':    return new RawWebSocketTransport(id, config);
    case 'sse':          return new SseTransport(id, config);
    case 'http-polling': return new HttpPollingTransport(id, config);
    default:
      throw new Error(`Unknown transport type: ${(config as any).type}`);
  }
}

TransportConfig Options

export interface TransportConfig {
  type: 'signalr' | 'websocket' | 'sse' | 'http-polling';
  url: string;            // hub URL or endpoint
  accessToken?: string;   // JWT for SignalR auth
  timeoutMs?: number;     // connection timeout in ms
  headers?: Record<string, string>;    // for HTTP-based transports
  queryParams?: Record<string, string>; // URL query parameters
  reconnect?: {
    maxAttempts: number;      // 0 = infinite
    initialDelayMs: number;   // delay before first retry
    maxDelayMs: number;       // max backoff cap
    backoffMultiplier: number; // exponential factor
  };
}

Accessing the Transport After Registration

const server = edgeStream.server('bas')!;

// Access transport for status monitoring
console.log(server.transport.type);    // 'signalr'
console.log(server.transport.status);  // 'disconnected' until start()
console.log(server.transport.id);      // 'transport-xxxx'

// Listen to transport status changes
server.transport.onStatusChange((status) => {
  console.log('Transport status:', status);
  // 'connecting' | 'connected' | 'reconnecting' | 'disconnected' | 'error'
});

server.transport.onError((error) => {
  console.error('Transport error:', error.message);
});