Logger

An Angular Logger service with multiple Appenders.

Install

$ npm i @stomp/logger

Usage

Create an Injectable class and a way to create it in logger-service.ts

// Define a class that can be injected by Angular DI
@Injectable({
  providedIn: 'root',
})
export class LoggerService extends Logger {}

// As per your application logic
const userId = '9be7ecd3-b706-43ee-9114-628241a808bd';
const sessionId = '972e139d-2426-4955-b2f9-74532e790722';

export function initLoggerService(rxStomp: RxStompService): LoggerService {
  // STOMP Appender will publish each log message to the provided destination
  const stompAppenderConfig = {
    // mandatory, the STOMP destination, typically a header/topic Exchange
    dest: '/exchange/user-log',
    // Minimum severity level to log
    level: LogLevel.DEBUG,
    // Provide a header for each log message
    // You may also alter the message
    formatter: message => ({
      headers: {
        user: userId,
        session: sessionId,
        ts: `${Date.now()}`,
      },
      message,
    }),
  };
  const stompAppender = new StompAppender(stompAppenderConfig, rxStomp);

  // Console Appender will show the messages on the console
  // The console does not have a call for `fatal` to that will be logged using
  // `console.error`
  const consoleAppender = new ConsoleAppender({
    // Minimum severity level to log
    level: LogLevel.DEBUG,
    // This is optional - it allows to modify the message being logged.
    // You can return an Array which will be passed to the console method
    // You may also alter the message.
    formatter: message => [new Date(), message],
  });

  const config: LoggerConfig = {
    // You can use any number of appenders
    appenders: [stompAppender, consoleAppender],
  };

  return new LoggerService(config);
}

Provide a LoggerService, typically in app.modules.ts

@NgModule({
  // ...
  providers: [
    // ...
    {
      provide: LoggerService,
      useFactory: initLoggerService,
      deps: [RxStompService],
    },
  ],
  bootstrap: [AppComponent],
})

To log messages:

// debug, info, warn, error, fatal (same as Ruby logger, or Log4J
logger.debug('my debug message');

New Appender

Implementing a new Appender is not complicated. See code for existing Appenders for help.

Watching the messages live

To watch the messages live, please use the watch.rb ruby script (using bunny gem for AMQP).