Trackit Console module

Allows you to output your logs like this

or like this

Trackit is a lightweight and modular logging system for Dart and Flutter. Trackit has a modular structure, which allows to avoid unused functionality.

trackit_console module for for Trackit. It is used to format and output logger events to the console. Thanks to the formatter system, it allows you to flexibly customize the output of events to the console. Using packages like ansicolor, you can add colors to your console.

In addition, you can use formatters separately, for example, to format the output before sending it to the log collection system or for displaying it in an application.

How to use

import 'package:trackit/trackit.dart';
import 'package:trackit_console/trackit_console.dart';

void main() {
  Trackit().listen(TrackitConsole(
    formatter: TrackitPatternFormater(),
  ).onData);

  final log = Trackit.create('MAIN');

  log.info('Hello world!');
  log.info('Log info message');
  log.info('Multiline\nlog\nmessage');

  log.debug('Debug message');
  try {
    throw Exception('Test Error exception message');
  } catch (exception, stackTrace) {
    log.error('catch error exception', exception, stackTrace);
  }
  try {
    throw Exception('Test Fatal exception message');
  } catch (exception, stackTrace) {
    log.fatal('catch fatal exception', exception, stackTrace);
  }
}

Formatters

TrackitJsonFormatter

Converts a log event to a Map<String,dynamic> that can be sent to a log collection system.

TrackitSimpleFormatter

Used to minimally convert a logger event into a string like this:

[info] 2024-11-19T13:20:52.488727 {MAIN} Log info message

It has two configuration parameters:

bool withException - Specifies whether to display error information if it exists (default is true)
bool withStackTrace - Specifies whether to display stackTrace information if it exists (default is true)

TrackitPatternFormater

Formats log output according to a template. This is a fairly flexible formatter. It allows you to flexibly customize the event string by adding or excluding parameters, for each of which you can specify methods for converting to a string.

The template is specified in the template parameter and is a string with replacers that will be replaced with the current values from the logger event. Template replacers can take the following values:

Pattern	Description
{L}	LogLevel first
{T}	Logger instance title
{D}	Log event time
{M}	Log event message
{E}	Log event exception
{S}	Log event stackTrace

In addition, you can specify how the string values of the logger event fields will be formed. To do this, use the stringify parameter. Pass it a function that forms a LogEventString object containing the string values of the fields. This parameter can be used to add colors to part of the output and to format the output. Here is an example of usage:

import 'package:trackit/trackit.dart';
import 'package:trackit_console/trackit_console.dart';

LogEventString stringifyEvent(LogEvent event) {
  String color() => switch (event.level) {
    LogLevelTrace() => '37m',
    LogLevelDebug() => '34m',
    LogLevelInfo() => '32m',
    LogLevelWarn() => '33m',
    LogLevelError() => '31m',
    LogLevelFatal() => '31m',
  };
  
  return LogEventString(
    level:
        '\x1B[${color()}${event.level.name.toUpperCase().substring(0, 1)}\x1B[0m',
    title: event.title.toUpperCase(),
    time: (event.time.millisecondsSinceEpoch ~/ 1000).toString(),
    message: event.message?.toString() ?? '',
  );
}

void main(){
  Trackit().listen(TrackitConsole(
    formatter: TrackitPatternFormater(
      pattern: '[{L}] <{D}> ({T}): {M}\n{E}\n{S}',
      stringify: stringifyEvent,
    ),
  ).onData);

  final log = Trackit.create('MAIN');
  log.info('Hello world!');
  log.debug('Debug message');

  try {
    throw Exception('Test Fatal exception message');
  } catch (exception, stackTrace) {
    log.fatal('catch fatal exception', exception, stackTrace);
  }
}

In addition, using the post parameter, you can post-process the generated string. For example, add color or a frame to it. Here is an example of use:

import 'package:trackit/trackit.dart';
import 'package:trackit_console/trackit_console.dart';

String color(LogEvent event) => switch (event.level) {
  LogLevelTrace() => '37m',
  LogLevelDebug() => '34m',
  LogLevelInfo() => '32m',
  LogLevelWarn() => '33m',
  LogLevelError() => '31m',
  LogLevelFatal() => '31m',
};

void main(){
  Trackit().listen(TrackitConsole(
    formatter: TrackitPatternFormater(
      pattern: '[{L}] <{D}> ({T}): {M}\n{E}\n{S}',
      post: (event, value) => [
        '\x1B[${color(event)}┌──────────────────────────────────────────────────────────────────\x1B[0m',
        ...value.split('\n').map((str) => '\x1B[${color(event)}│ $str\x1B[0m'),
        '\x1B[${color(event)}└──────────────────────────────────────────────────────────────────\x1B[0m',
      ].join('\n'),
    ),
  ).onData);

  final log = Trackit.create('MAIN');
  log.info('Hello world!');
  log.debug('Debug message');

  try {
    throw Exception('Test Fatal exception message');
  } catch (exception, stackTrace) {
    log.fatal('catch fatal exception', exception, stackTrace);
  }
}

See full documentation for details.