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4.1.9 • Public • Published

npm version

NGX Logger

NGX Logger is a simple logging module for angular (currently supports angular 6+). It allows "pretty print" to the console, as well as allowing log messages to be POSTed to a URL for server-side logging.

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We need your help!

As open source projects grow, they become more and more work to maintain. Feature requests and bug fixes take up more and more time. We need your help to make sure we can support our community well. If you're interested in supporting ngx-logger by answering question on github, or submitting PRs for bug fixes or feature requests, please reach out to us! We would love your help!

Breaking changes for NGX Logger 3.* to 4.*

  • Importing mocks and the logger testing module should now be imported from the new testing entrypoint
    • import {LoggerTestingModule} from 'ngx-logger/testing';

Latest Updates to NGX Logger

  • Support for Custom Color Schemes in the config
    • uses the LoggerColorScheme type, it is an array of 7 colors, each color matches to a log level. see LogLevelEnum
  colorScheme: ['purple', 'teal', 'gray', 'gray', 'red', 'red', 'red']
  • Support to set WithCredentials on your HTTP requests.
  • Support for custom parsing of source maps. In order to use it, you must set enableSourceMaps: true in your logger config

    • Note: In order for the enableSourceMaps flag to work, your app must generate the source maps during the build process. If your using AngularCli you can generate Source Maps by setting "sourceMap": {"scripts": true} (or for older version of angularCli "sourceMap": true) in your angular.json
  • Support of responseType for HTTP Requests. A new config option httpResponseType now allows you to set your server's response type.

  • Custom HTTP Params

    • If you need to pass in custom HTTP Params to your backend server, you can now use setCustomParams().
  this.logger.setCustomParams(new HttpParams());
  • Using the NGXLoggerMonitor and want to disable console logs? Now you can!

    • New config option disableConsoleLogging will disable console logs, but still alert to the log monitor.
  • Custom HTTP Headers

    • If you use an auth token, or need to pass in a custom header, now you can!
  this.logger.setCustomHttpHeaders(new HttpHeaders({'X-Custom-Header': '123456'}));
  • Custom Log Monitoring is now available.
    • Only one monitor can be registered at a time; registering a new monitor overwrites the previous monitor.
    • This should be registered as soon as possible so that it does not miss any logs.
  import {NGXLoggerMonitor, NGXLogInterface} from 'ngx-logger';
  export class MyLoggerMonitor implements NGXLoggerMonitor {
    onLog(log: NGXLogInterface) {
      console.log('myCustomLoggerMonitor', log);
  import {NGXLogger} from 'ngx-logger';
  import {MyLoggerMonitor} from './my-logger-monitor';
  export class MyService {
    constructor(private logger: NGXLogger) {
      this.logger.registerMonitor(new MyLoggerMonitor());
  • Updating your config after importing the module has never been easier...
  this.logger.updateConfig({ level: NgxLoggerLevel.DEBUG });
  • You can now create a standalone logger with its own config!
  export class MyService {
    private logger: NGXLogger;
    constructor(customLogger: CustomNGXLoggerService) {
      this.logger = customLogger.create({ level: NgxLoggerLevel.ERROR });


  • @angular/common
  • @angular/core


npm install --save ngx-logger

Once installed you need to import our main module:

import { LoggerModule, NgxLoggerLevel } from 'ngx-logger';

The only remaining part is to list the imported module in your application module, passing in a config to intialize the logger.

  declarations: [AppComponent, ...],
  imports: [LoggerModule.forRoot({serverLoggingUrl: '/api/logs', level: NgxLoggerLevel.DEBUG, serverLogLevel: NgxLoggerLevel.ERROR}), ...],
  bootstrap: [AppComponent]
export class AppModule {


To use the Logger, you will need import it locally, then call one of the logging functions

import { Component } from '@angular/core';
import { NGXLogger } from 'ngx-logger';
  selector: 'your-component',
  templateUrl: './your.component.html',
  styleUrls: ['your.component.scss']
export class YourComponent {
  constructor(private logger: NGXLogger) {
    this.logger.debug('Your log message goes here');
    this.logger.debug('Multiple', 'Argument', 'support');

Config Options

  • level {NgxLoggerLevel}: only log messages of this level or higher (OFF disables the logger for the client).
  • disableConsoleLogging {boolean}: disables console logging, while still alerting the log monitor.
  • serverLogLevel {NgxLoggerLevel}: only send log messages of this level or higher to the server (OFF disables the logger for the server).
  • serverLoggingUrl {string}: URL to POST logs.
  • httpResponseType {'arraybuffer' | 'blob' | 'text' | 'json'}: the response type of the HTTP Logging request.
  • enableSourceMaps {boolean}: enables manual parsing of Source Maps
    • Note: In order for the enableSourceMaps flag to work, your app must generate the source maps during the build process. If your using AngularCli you can generate Source Maps by setting "sourceMap": {"scripts": true} (or for older version of angularCli "sourceMap": true) in your angular.json
  • timestampFormat {string}: format for the timestamp displayed with each log message. Can be any of the formatting options accepted by the classic Angular DatePipe.
  • colorScheme {LoggerColorScheme}: a color scheme that defines which color should be used for each log level
    • Note: the index of the scheme relates to the log level value


Server-Side Logging

If serverLoggingUrl exists, NGX Logger will attempt to POST that log to the server.

The payload body is of type NGXLogInterface

Testing Your App When Using NGXLogger

If you inject any of the NGX Logger services into your application, you will need to provide them in your Testing Module. All services have mocked classes that can be used for testing:

  • NGXLoggerHttpService: NGXLoggerHttpServiceMock
  • CustomNGXLoggerService: CustomNGXLoggerServiceMock
  • NGXLogger: NGXLoggerMock

To provide them in your Testing Module:

  imports: [

Demo App

There is a demo application with examples of how to use ngx-logger. To run it perform the following:

  • Clone the repo
  • Run npm ci or npm install
  • Build ngx-logger using ng build
  • Run ng serve demo to serve the app

A convenience script has been added to package.json that performs the above steps. Simply run npm run demo to have the demo built and served.


All are welcome to contribute to NGX Logger. A couple quick notes to get started:

  • NGX Logger is built with angular-cli
  • To use npm link, you must link the /src (or /dist after it is built) directory not root.
  • When possible, try to follow patterns that have already been established in the library
  • Try to make your code as simple as possible
    • Even if the code could be made shorter, having code that is readable and easily understood is way more valuable
  • Have fun!


npm i ngx-logger

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