Create a Custom Driver

Implement LumberjackLogDriver and register it with lumberjackLogDriverToken (multi: true) so Lumberjack forwards matching logs to your sink.

Before you start

Familiarity with how log drivers work.
Lumberjack registered via provideLumberjack().

Steps

Implement the driver

Each method receives a LumberjackLogDriverLog with formattedLog and log.

import { inject, Injectable } from '@angular/core';
import {
  LumberjackLogDriver,
  LumberjackLogDriverConfig,
  LumberjackLogDriverLog,
  lumberjackLogDriverConfigToken,
} from '@ngworker/lumberjack';

@Injectable()
export class AnalyticsDriver implements LumberjackLogDriver {
  static readonly driverIdentifier = 'AnalyticsDriver';

  readonly config: LumberjackLogDriverConfig = {
    ...inject(lumberjackLogDriverConfigToken),
    identifier: AnalyticsDriver.driverIdentifier,
  };

  logCritical({ formattedLog }: LumberjackLogDriverLog): void {
    console.error(formattedLog);
  }

  logDebug({ formattedLog }: LumberjackLogDriverLog): void {
    console.debug(formattedLog);
  }

  logError({ formattedLog }: LumberjackLogDriverLog): void {
    console.error(formattedLog);
  }

  logInfo({ formattedLog }: LumberjackLogDriverLog): void {
    console.info(formattedLog);
  }

  logTrace({ formattedLog }: LumberjackLogDriverLog): void {
    console.trace(formattedLog);
  }

  logWarning({ formattedLog }: LumberjackLogDriverLog): void {
    console.warn(formattedLog);
  }
}

Provide it with the multi token

import { Provider } from '@angular/core';
import { lumberjackLogDriverToken } from '@ngworker/lumberjack';

import { AnalyticsDriver } from './analytics.driver';

export function provideAnalyticsDriver(): Provider[] {
  return [
    {
      provide: lumberjackLogDriverToken,
      useClass: AnalyticsDriver,
      multi: true,
    },
  ];
}

Register at bootstrap

import { bootstrapApplication } from '@angular/platform-browser';
import { provideLumberjack } from '@ngworker/lumberjack';

import { AppComponent } from './app/app.component';
import { provideAnalyticsDriver } from './app/logging/provide-analytics-driver';

bootstrapApplication(AppComponent, {
  providers: [provideLumberjack(), provideAnalyticsDriver()],
});

Variations

Driver-specific config

Mirror the console/HTTP drivers: create a config token, merge lumberjackLogDriverConfigToken with your options (and a stable identifier), then inject that token on the driver. See provideLumberjackConsoleDriver and provideLumberjackHttpDriver in the reference.

Typed payloads

Parameterize LumberjackLogDriver<MyPayload> and read log.payload inside each method. Feature loggers must use the same payload type.

Verify

Emit a log through LumberjackService or a logger and confirm your driver’s method runs (breakpoint or sink assertion).